Environmental Science › Nature and Landscape Conservation

Fish biology, ecology, and behavior

Works Count: 54387

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Description

This cluster of papers focuses on the biogeography, conservation, and ecological dynamics of Neotropical freshwater fishes, with an emphasis on the Amazon River system. It covers topics such as fish biodiversity, impacts of hydropower dams, aging research using short-lived fish species, tropical river fisheries, electroreception in fishes, and the effects of habitat degradation on fish assemblages. The papers also explore the historical biogeography and evolutionary history of Neotropical freshwater fishes.

Keywords

Freshwater Ecoregions; Fish Biodiversity; Amazon River System; Hydropower Dams; Neotropical Fish Assemblages; Aging Research; Tropical River Fisheries; Electroreception in Fishes; Habitat Degradation; Biogeographical Patterns

Fish Biogeography and Molecular Clocks: Perspectives from the Panamanian Isthmus

1997-01-01

Eldredge Bermingham , S. Shawn McCafferty , Andrew Martin

The lateral line can mediate rheotaxis in fish

1997-10-01

John C. Montgomery , Cindy F. Baker , Alexander G. Carton

The vulnerability of Amazon freshwater ecosystems

2013-01-01

Leandro Castello , David McGrath , Laura L. Hess +6 more

Abstract The hydrological connectivity of freshwater ecosystems in the Amazon basin makes them highly sensitive to a broad range of anthropogenic activities occurring in aquatic and terrestrial systems at local … Abstract The hydrological connectivity of freshwater ecosystems in the Amazon basin makes them highly sensitive to a broad range of anthropogenic activities occurring in aquatic and terrestrial systems at local and distant locations. Amazon freshwater ecosystems are suffering escalating impacts caused by expansions in deforestation, pollution, construction of dams and waterways, and overharvesting of animal and plant species. The natural functions of these ecosystems are changing, and their capacity to provide historically important goods and services is declining. Existing management policies—including national water resources legislation, community‐based natural resource management schemes, and the protected area network that now epitomizes the Amazon conservation paradigm—cannot adequately curb most impacts. Such management strategies are intended to conserve terrestrial ecosystems, have design and implementation deficiencies, or fail to account for the hydrologic connectivity of freshwater ecosystems. There is an urgent need to shift the Amazon conservation paradigm, broadening its current forest‐centric focus to encompass the freshwater ecosystems that are vital components of the basin. This is possible by developing a river catchment‐based conservation framework for the whole basin that protects both aquatic and terrestrial ecosystems.

The Electric Sense of Sharks and Rays

1971-10-01

Ad. J. Kalmijn

ABSTRACT Previous experiments have demonstrated that (a) the shark Scyliorhinus canicula and the ray Raja clavata are extremely sensitive to weak electric fields ; (b) their electrical sensitivity is due … ABSTRACT Previous experiments have demonstrated that (a) the shark Scyliorhinus canicula and the ray Raja clavata are extremely sensitive to weak electric fields ; (b) their electrical sensitivity is due to the ampullae of Lorenzini; (c) the sharks and rays can be stimulated by the bioelectric fields emanating from the flatfish Pleuronectes platessa. When hungry, Scyliorhinus and Raja perform well-aimed feeding responses to flatfish, even if the prey have covered themselves with sand. The object of the present study was to determine whether the sharks and rays use the bioelectric fields of the flatfish to detect the position of their prey. To analyse the feeding responses of the sharks and rays, a flatfish was put into an agar chamber. The predators responded to the so screened prey from the same distance, and tried to feed on it in the same way as if there were no agar at all. As the flatfish in the agar chamber was completely hidden from view, the sharks and rays were thus shown not to need visual contact to locate the prey. If the agar chamber was filled with cut-up pieces of whiting, the sharks and rays did not respond to the food, although the odour of whiting juice normally attracts them strongly. Therefore, the sharks and rays did not detect the position of the agarscreened flatfish by smell. The feeding responses to the flatfish could be entirely abolished by covering the agar chamber with a very thin sheet of plastic. The mechanical attenuation offered by the plastic film was too weak to explain its dramatic inhibitory effect, and, thus, a purely mechanical detection of the agar-screened flatfish without plastic film was also ruled out. As the responses to the agar-screened flatfish were not merely due to visual, chemical, or mechanical stimuli, it was tentatively concluded that the sharks and rays perceived the prey electrically. This conclusion was fully in agreement with the results of the experiments, for the agar chamber did not appreciably distort the bioelectric fields of the flatfish, and the electrical impedance of the plastic film was extremely high. Further, the bioelectric field of a flatfish was simulated with a pair of electrodes, buried in the sand. Now, the sharks and rays displayed exactly the same feeding responses to the electrodes as they did previously to the real prey. This crucial experiment confirmed the electrical hypothesis in a very direct way. The experiments described demonstrate clearly that the shark Scyliorhinus canicula and the ray Raja clavata make a biologically significant use of their electrical sensitivity. Therefore, we now are justified in accrediting the animals with an electric sense and in designating the ampullae of Lorenzini as electroreceptors. When the sharks and rays were offered a piece of whiting in the vicinity of two electrodes simulating a flatfish, they were attracted by the odour of the food but usually performed their well-aimed responses to the electrodes. Thus, at short range» the electric fields act as a much stronger directive force than do the visual and chemical stimuli. Only direct mechanical contact dominates over the electrical stimuli. Theoretically, the sharks and rays can detect the electric fields resulting from oceanic and tidal currents. Whether they make use of the available information for orientation in the open sea is not yet known. Furthermore, the observations and measurements described indicate that, in studying shark attacks, the electric fields of the prey and the electric sense of the predators should be taken into account.

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The Mechanism of Object Location in Gymnarchus Niloticus and Similar Fish

1958-06-01

H. W. Lissmann , K. E. Machin

ABSTRACT Experiments with moving electrostatic and magnetic fields show that Gymnarchus niloticus is sensitive to a potential gradient of about 0 · 03 µ V./cm. Alternative explanations of some previous … ABSTRACT Experiments with moving electrostatic and magnetic fields show that Gymnarchus niloticus is sensitive to a potential gradient of about 0 · 03 µ V./cm. Alternative explanations of some previous experiments are given in terms of this high d.c. sensitivity. An explanation in similar terms is given of experiments in which Gymnotus carapo is trained to detect a stationary magnet. The mechanisms available for the location of objects by electric fish are reviewed. It is concluded from the results of a critical experiment (described in a succeeding section) that Gymnarchus niloticus can detect objects by the disturbance of its own electric field in the water. The approximate theory of this method of object location is derived. The effect on the receptors of the perturbing field due to an object depends on the electrical properties of the receptors: in the extreme cases the stimulation of the receptors is proportional either to the potential or to its second derivative. Graphs are given showing the effect of an object on the potential and on its second derivative around the surface of the fish. Experiments are described using Gymnarchus niloticus which (a) confirm that the mechanism of object location employs electric field distortion ; (i) indicate the limits of the sensitivity of the fish. The second derivative mode appears to be the most probable one operating in Gymnarchus. The experimentally determined limits of detection are discussed in relation to the random noise in the receptor circuit : it is concluded that both spatial and temporal integration are likely to be employed. The thresholds for object location and for response to direct currents are compared : it is concluded that the same receptors are probably operating in both cases.

Electric and Magnetic Field Detection in Elasmobranch Fishes

1982-11-26

Ad. J. Kalmijn

Sharks, skates, and rays receive electrical information about the positions of their prey, the drift of ocean currents, and their magnetic compass headings. At sea, dogfish and blue sharks were … Sharks, skates, and rays receive electrical information about the positions of their prey, the drift of ocean currents, and their magnetic compass headings. At sea, dogfish and blue sharks were observed to execute apparent feeding responses to dipole electric fields designed to mimic prey. In training experiments, stingrays showed the ability to orient relative to uniform electric fields similar to those produced by ocean currents. Voltage gradients of only 5 nanovolts per centimeter would elicit either behavior.

A Classification of Major Naturally-Occurring Amazonian Lowland Wetlands

2011-07-07

Wolfgang J. Junk , María Teresa Fernández Piedade , Jochen Schöngart +3 more

Proliferation of Hydroelectric Dams in the Andean Amazon and Implications for Andes-Amazon Connectivity

2012-04-18

Matt Finer , Clinton N. Jenkins

Due to rising energy demands and abundant untapped potential, hydropower projects are rapidly increasing in the Neotropics. This is especially true in the wet and rugged Andean Amazon, where regional … Due to rising energy demands and abundant untapped potential, hydropower projects are rapidly increasing in the Neotropics. This is especially true in the wet and rugged Andean Amazon, where regional governments are prioritizing new hydroelectric dams as the centerpiece of long-term energy plans. However, the current planning for hydropower lacks adequate regional and basin-scale assessment of potential ecological impacts. This lack of strategic planning is particularly problematic given the intimate link between the Andes and Amazonian flood plain, together one of the most species rich zones on Earth. We examined the potential ecological impacts, in terms of river connectivity and forest loss, of the planned proliferation of hydroelectric dams across all Andean tributaries of the Amazon River. Considering data on the full portfolios of existing and planned dams, along with data on roads and transmission line systems, we developed a new conceptual framework to estimate the relative impacts of all planned dams. There are plans for 151 new dams greater than 2 MW over the next 20 years, more than a 300% increase. These dams would include five of the six major Andean tributaries of the Amazon. Our ecological impact analysis classified 47% of the potential new dams as high impact and just 19% as low impact. Sixty percent of the dams would cause the first major break in connectivity between protected Andean headwaters and the lowland Amazon. More than 80% would drive deforestation due to new roads, transmission lines, or inundation. We conclude with a discussion of three major policy implications of these findings. 1) There is a critical need for further strategic regional and basin scale evaluation of dams. 2) There is an urgent need for a strategic plan to maintain Andes-Amazon connectivity. 3) Reconsideration of hydropower as a low-impact energy source in the Neotropics.

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Dams and the fish fauna of the Neotropical region: impacts and management related to diversity and fisheries

2008-11-01

Ângelo Antônio Agostinho , FM. Pelicice , Luiz Carlos Gomes

Reservoirs have been built in almost all of the hydrographic basins of Brazil. Their purposes include water supply for cities, irrigation and mainly, generation of electricity. There are more than … Reservoirs have been built in almost all of the hydrographic basins of Brazil. Their purposes include water supply for cities, irrigation and mainly, generation of electricity. There are more than 700 large dams and associated reservoirs in the large rivers of the country. These reservoirs favor local and regional economic development, but they also bring serious and irreversible alterations in the natural hydrologic regime of rivers, affecting habitat quality and the dynamics of the biota. In the impounded area, the main impact is the change from lotic to lentic water, which influences aquatic fauna, including fishes. Impacts of reservoirs present relevant spatiotemporal variations. Immediately after reservoir formation, fish species richness usually increases due to incorporation of surrounding habitats, but richness decreases as reservoirs age. However, impacts downstream of dams appear to be similar or stronger than those that occur within the reservoir. Dams promote discharge control, altering the seasonal cycles of floods. These effects are augmented when dams are constructed in cascades. Therefore, dams profoundly influence composition and structure of fish assemblages. Most affected species are the rheophilics and long distance migratory that require distinct habitats to fulfill their life cycles. Populations of migratory species may collapse or even disappear in intensely regulated stretches. Management actions taken to minimize impacts of dams in Brazil historically considered construction of fish passages, fishery control and stocking. The results of these actions are questionable and/or with clear failures. In this paper, we give emphasis to the Paraná River basin, the most affected by dams in Brazil. We describe some patterns in the alteration and decline in fish diversity in areas influenced by dams. We also discuss negative consequences in the fishery and ecosystems functioning. Finally, we argue the relevance and the success of the management actions taken and present some suggestions to improve conservation of the ichthyofauna in South American basins influenced by dams.

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Homing by path integration in a mammal

1980-11-01

Marie-Luise Mittelstaedt , H Mittelstaedt

The Adequacy of Body Size as a Niche Difference

1975-11-01

David Sloan Wilson

Patterns of variation in life history among South American fishes in seasonal environments

1989-10-01

Kirk O. Winemiller

Habitat Structure and Stream Fish Communities

1978-05-01

Owen T. Gorman , James R. Karr

Flood regime, dam regulation and fish in the Upper Paran� River: effects on assemblage attributes, reproduction and recruitment

2004-03-01

Ângelo Antônio Agostinho , Luiz Carlos Gomes , Samuel Ver�ssimo +1 more

Competition in Tropical Stream Fishes: Support for the Competitive Exclusion Principle

1971-03-01

Thomas M. Zaret , A. Stanley Rand

Two collections of fish were made from the same Panama lowland stream, one during the dry season, and a second during the wet season. Food overlaps among nine sympatric fish … Two collections of fish were made from the same Panama lowland stream, one during the dry season, and a second during the wet season. Food overlaps among nine sympatric fish species were calculated for each collection by examining fish stomach contents. Species habitats and feeding methods were determined from field and laboratory observations. Estimates of food abundance, measured independently from food overlap, were made by direct and indirect methods, and were used to determine relative levels of competition. The results show that food overlaps among the fishes are at a minimum during the dry season. Food abundance is also lowest during the dry season, which suggests increased competition for food at this time. This seasonal coincidence of the most distinct species separations with the time of increased competition are exactly those consequences predicted by the principle of competitive exclusion. It is concluded that this study provides strong support for the validity of this principle.

The Tree of Life and a New Classification of Bony Fishes

2013-01-01

Ricardo Betancur‐R , Richard E. Broughton , E. O. Wiley +7 more

Vertebrate bone is composed of three main cell types: osteoblasts, osteoclasts and osteocytes, the latter being by far the most numerous.Osteocytes are thought to play a fundamental role in bone … Vertebrate bone is composed of three main cell types: osteoblasts, osteoclasts and osteocytes, the latter being by far the most numerous.Osteocytes are thought to play a fundamental role in bone physiology and homeostasis, however they are entirely absent in most extant species of teleosts, a group that comprises the vast majority of bony 'fishes', and approximately half of vertebrates.Understanding how this acellular (anosteocytic) bone appeared and was

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Further contributions to the study of the evolution of the forebrain

1923-08-01

J. B. Johnston

River dynamics and the diversity of Amazon lowland forest

1986-07-01

Jukka Salo , Risto Kalliola , Ilmari Häkkinen +4 more

Global diversity of fish (Pisces) in freshwater

2007-12-17

Christian Lévêque , Thierry Oberdorff , Didier Paugy +2 more

Species Introduction in a Tropical Lake

1973-11-02

Thomas M. Zaret , Robert T. Paine

Probably in early 1967, a piscivore from South America, Cichla ocellaris , was introduced to Gatun Lake in the Panama Canal Zone. As this predator population spread through the lake, … Probably in early 1967, a piscivore from South America, Cichla ocellaris , was introduced to Gatun Lake in the Panama Canal Zone. As this predator population spread through the lake, the initial effect was dramatic reductions in almost all secondary consumers. These species reductions produced, in turn, second- and third-order changes at other trophic levels of the ecosystem. The resulting changes in the lake community can be seen best by examining the general Gatun Lake food web. The decrease in numbers of the important planktivore Melaniris has resulted in changes within the zooplankton community, as illustrated by the cladoceran Ceriodaphnia . The tertiary-consumer populations, such as tarpon, black terns, kingfishers, and herons, formerly dependent on small fishes for food, appear less frequently in the Cichla areas of the lake. There has also been, possibly, a resurgence of the local mosquito populations (which are malaria vectors), caused by the reduction in the populations of insect-eating fishes. Even the primary producers may be affected by this introduction. Although at present the Gatun Lake ecosystem is undergoing rapid changes, we anticipate an eventual return to some form of equilibrium. However, it will be some time before we can evaluate the permanence or transience of the many changes produced in the trophic levels by the introduction of a single, top-level predator to this lake system.

THE FUNCTIONING and SIGNIFICANCE OF THE LATERAL‐LINE ORGANS

1963-02-01

S. Dijkgraaf

Spatial and Temporal Variation in Tropical Fish Trophic Networks

1990-09-01

Kirk O. Winemiller

Observed properties of natural food webs have both important theoretical and important management implications. Four lowland aquatic food webs were investigated over the course of two years: a large swamp … Observed properties of natural food webs have both important theoretical and important management implications. Four lowland aquatic food webs were investigated over the course of two years: a large swamp and a small stream in Costa Rica, and a similar swamp and stream in the Venezuelan llanos. Each local ecosystem differed from the three others with respect to environmental changes associated with seasonal rainfall. Phylogenetic composition and diversity of biotas also varied among systems. Volumetric proportional utilization coefficients from fish gut contents were used as estimates of the intensity of predator—prey interactions. An annual and two or more seasonal food webs were constructed for each local community. Aquatic communities were defined operationally using common fish species as consumers, and using the sink subweb associated with the top predator of each system. A computer calculated a variety of food—web statistics and plotted food—web diagrams containing either (a) all observed trophic links (predator—prey interactions), or (b) subsets with weak links eliminated at prescribed thresholds. Individual community food webs contained from 58 (stream, Costa Rica) to 104 (swamp, Venezuela) interactive taxonomic units and from 208 to 1243 total trophic links. Food—web parameters were very sensitive to changes in level of link threshold. Web connectance and related parameters converged near link threshold 0.04 (utilization coefficients <0.04 eliminated) in a variety of inter—web comparisons. Despite large differences in assemblage composition and attributes of the physical environment, distributions of trophic levels calculated according to a trophic continuum algorithm were very similar among study systems. Herbivores, detritivores, and their direct predators formed the largest proportions of fishes in each assemblage, followed by omnivores and secondary carnivores. Fishes that fed at more than one trophic interval were extremely common in all food webs. Analysis of covariance was used to compare structural features of different webs across a range of link thresholds. Extensive among—site variation in food—web parameters was associated with differences in species richness and environmental differences associated with rainfall patterns, physiography, and gross primary production. Seasons generally influenced food—web parameters less than did site differences. Relative importance of detritus, aquatic primary production, and terrestrial production in aquatic food webs varied seasonally in each system. Detritus, derived primarily from aquatic macrophytes, was an important pathway in both tropical swamp ecosystems. Aquatic primary productivity comprised the largest fraction of fish diets during the wet season in the Venezuelan swamp, but it formed the major component of fish diets during the dry season at all other sites. Based on comparisons using 13 webs, two—thirds of the pairings among six food—web parameters used (number of nodes, compartmentation, connectance, average number of prey per node, average number of predators per node, ratio of consumer nodes to total nodes) were positively intercorrelated. Several food—web relationships previously described as constant (e.g., connectance x species richness constancy, species scaling law, link—species scaling law) were not confirmed by my data. These earlier food—web trends are extremely sensitive to methodological biases, especially decisions regarding the degree of taxonomic lumping of species into trophic units. Although food webs have unique emergent properties and spinoff a number of potentially informative macrodescriptors, empirical studies must achieve greater precision and uniformity before analyses can be performed across different systems. Several problems and potential resolutions are discussed.

Ecological opportunity and sexual selection together predict adaptive radiation

2012-06-08

Catherine E. Wagner , Luke J. Harmon , Ole Seehausen

Ecomorphological Diversification in Lowland Freshwater Fish Assemblages from Five Biotic Regions

1991-12-01

Kirk O. Winemiller

This study investigates the relationships among species diversity, community structure, and convergent evolution among divergent fish faunas. Morphological traits can be used as surrogates for ecological data in the comparative … This study investigates the relationships among species diversity, community structure, and convergent evolution among divergent fish faunas. Morphological traits can be used as surrogates for ecological data in the comparative study of community niche relationships. In the present study I examined 30 morphological features related to the ecology of the dominant fish species from lowland stream and backwater habitats in five widely separated geographic regions: nearctic Alaska, temperate North America, Central America, South America, and tropical Africa. The study regions exhibited a general gradient of species richness from a minimum of 6 dominant species at one of the high—latitude sites (65° N) to a maximum of 43 numerically dominant species at a neotropical site (8° N). Fishes from Alaskan sites near the edge of the polar circle tended to be larger than fishes at other sites. Mean values for most morphological characters varied little between regions, indicating similar faunal centroids in morphological space. Morphological diversification within fish assemblages was estimated from species similarities based on Euclidean distances plus species projections on the principal axes from multivariate analysis. The total morphological space encompassed by ichthyofaunas in both stream and backwater sites was generally concordant with the latitudinal and species—richness gradient, with low—diversity nearctic assemblages exhibiting little morphological diversification relative to high—diversity tropical faunas. The Central American assemblages showed a greater range of ecomorphological diversification than African assemblages that contained a few more species, and this pattern may be related to greater seasonal stability at the Central American site. Phenetic patterns of dispersion reflect ecological relationships in which greater numbers of coexisting species are associated with higher levels of niche diversification and ecological specialization, leading to enhanced resource partitioning. Without additional ecological information, a community morphological analysis cannot directly determine whether or not increased ecological specialization is associated with the addition of new resources on the fringes of resource space or with increased subdivision of previously utilized core resources. Based on ecological information gathered concurrently with the fishes used in this analysis, I conclude that close species packing in morphological space is associated with niche generalists rather than with niche compression. With the possible exception of the two high—latitude sites, assemblages that contained more fish species generally did not exhibit tighter packing in niche space than species—poor assemblages, and this result was observed for comparisons both within and between regions. In contrast with several earlier studies, I interpret the lack of correlation between species richness and the average minimum distance between species in assemblage morphospace as being entirely consistent with the observed expansion of morphospace with species richness and latitude. Morphological patterns show that average spacing is held more or less constant as the variety of ecomorphological configurations increases in more—speciose fish assemblages. Even though morphological characters reflect community relationships, tight packing near the center of faunal morphospace actually indicates the opposite of species packing (niche compression) in the traditional sense of resource—utilization curves. The analysis supports the thesis that species interactions are important determinants of community morphological features, particularly in species—rich tropical regions. Relative to assemblages in the other four regions, the two Alaskan fish assemblages were hyperdispersed within a comparatively small morphological space. The Alaskan fish assemblages probably formed via geologically recent, and perhaps repeated, colonizations of polar freshwaters by species with evolutionary histories in more diverse southern and coastal fish faunas. I interpret evidence of greater niche diversification at lower latitudes within a habitat type as being derived primarily from the influence of competition and predation, whereas differences between habitats within regions seems to be associated with the combined effects of biotic interactions and differences in habitat volume and heterogeneity. Even though different regions within ecomorphological space were dominated by different fish orders, numerous ecomorphological convergences and several one—for—one ecological equivalents were identified within different biotic regions.

Phylogeny and tempo of diversification in the superradiation of spiny-rayed fishes

2013-07-15

Thomas J. Near , Alex Dornburg , Ron I. Eytan +7 more

Spiny-rayed fishes, or acanthomorphs, comprise nearly one-third of all living vertebrates. Despite their dominant role in aquatic ecosystems, the evolutionary history and tempo of acanthomorph diversification is poorly understood. We … Spiny-rayed fishes, or acanthomorphs, comprise nearly one-third of all living vertebrates. Despite their dominant role in aquatic ecosystems, the evolutionary history and tempo of acanthomorph diversification is poorly understood. We investigate the pattern of lineage diversification in acanthomorphs by using a well-resolved time-calibrated phylogeny inferred from a nuclear gene supermatrix that includes 520 acanthomorph species and 37 fossil age constraints. This phylogeny provides resolution for what has been classically referred to as the “bush at the top” of the teleost tree, and indicates acanthomorphs originated in the Early Cretaceous. Paleontological evidence suggests acanthomorphs exhibit a pulse of morphological diversification following the end Cretaceous mass extinction; however, the role of this event on the accumulation of living acanthomorph diversity remains unclear. Lineage diversification rates through time exhibit no shifts associated with the end Cretaceous mass extinction, but there is a global decrease in lineage diversification rates 50 Ma that occurs during a period when morphological disparity among fossil acanthomorphs increases sharply. Analysis of clade-specific shifts in diversification rates reveal that the hyperdiversity of living acanthomorphs is highlighted by several rapidly radiating lineages including tunas, gobies, blennies, snailfishes, and Afro-American cichlids. These lineages with high diversification rates are not associated with a single habitat type, such as coral reefs, indicating there is no single explanation for the success of acanthomorphs, as exceptional bouts of diversification have occurred across a wide array of marine and freshwater habitats.

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Synaptic plasticity in a cerebellum-like structure depends on temporal order

1997-05-01

Curtis C. Bell , Victor Z. Han , Yoshiko Sugawara +1 more

ALLOMETRY AND SIZE IN ONTOGENY AND PHYLOGENY

1966-11-01

Stephen Jay Gould

Biodiversity and its conservation in the Pantanal of Mato Grosso, Brazil

2006-08-11

Wolfgang J. Junk , Cátia Nunes da Cunha , Karl M. Wantzen +4 more

The Geochemistry of the Amazon River System: Part I. The Factors that Control the Salinity and the Composition and Concentration of the Suspended Solids

1967-01-01

Ronald J. Gibbs

Research Article| October 01, 1967 The Geochemistry of the Amazon River System: Part I. The Factors that Control the Salinity and the Composition and Concentration of the Suspended Solids RONALD … Research Article| October 01, 1967 The Geochemistry of the Amazon River System: Part I. The Factors that Control the Salinity and the Composition and Concentration of the Suspended Solids RONALD J GIBBS RONALD J GIBBS Dept. Geology, University of California, Los Angeles, California (in co-operation with the Instituto Nacional de Pesquisas da Amazônia, Manaus, Brazil) Search for other works by this author on: GSW Google Scholar GSA Bulletin (1967) 78 (10): 1203–1232. https://doi.org/10.1130/0016-7606(1967)78[1203:TGOTAR]2.0.CO;2 Article history received: 14 Feb 1967 first online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation RONALD J GIBBS; The Geochemistry of the Amazon River System: Part I. The Factors that Control the Salinity and the Composition and Concentration of the Suspended Solids. GSA Bulletin 1967;; 78 (10): 1203–1232. doi: https://doi.org/10.1130/0016-7606(1967)78[1203:TGOTAR]2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract On the basis of wet- and dry-season sampling along the Amazon River, at its mouth, and from its 16 large tributaries, the factors that control the salinity and the composition and concentration of the suspended solids of the Amazon River were determined.The multiple regression analysis of the analytical results of 74 river-water samples and numerous in situ measurements revealed: (1) of the 92 percent of the variability of the salinity accounted for, 85 percent was accounted for by relief—86 percent of the total dissolved salts discharged by the Amazon was supplied from the 12 percent of the total area of the Basin comprising the mountainous-environment type; (2) of the 62 percent of the variability of the concentration of the suspended solids accounted for, 43 percent was accounted for by relief—82 percent of the total suspended solids discharged by the Amazon was supplied from the mountainous environment-type.The multiple regression analysis of the analytical results obtained by X-ray diffraction from 50 suspended solids samples revealed: (1) increased-relief physical weathering controlled the percentages of quartz, plagioclase, K-feldspar, mica, chlorite, and amphibole; (2) the percentage of “calcic” rocks in the upper portions of tributary basins controlled montmorillonite concentrations; and (3) a combination of low-relief chemical weathering and the percentage of igneous and metamorphic rocks controlled the percentages kaolinite and gibbsite.The increased-relief physical weathering dominant in the Andean mountainous environment controls the geochemistry of the Amazon River, indicated by the following observations: (1) the over-all composition of the suspended solids discharged by the Amazon differs only slightly from that of the suspended solids eroded from the mountainous environment; and (2) 84 percent of the total amount of dissolved salts and suspended solids discharged is eroded from the 12 percent of the total area of the Amazon Basin comprising the mountainous Andean environment-type. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

The sensory basis of fish schools: Relative roles of lateral line and vision

1980-01-01

Brian L. Partridge , Tony J. Pitcher

Interrelationships of the ostariophysan fishes (Teleostei)

1981-08-01

Sara V. Fink , William L. Fink

The history of ostariophysan classification is summarized and it is noted that traditional concepts of relationships have never been supported by characters found to be unique to the taxa. We … The history of ostariophysan classification is summarized and it is noted that traditional concepts of relationships have never been supported by characters found to be unique to the taxa. We present a new hypothesis of relationships among four of the five major ostariophysan lineages: Cypriniformes, Characiformes, Siluroidei, and Gymnotoidei (Otophysi). Cypriniforms are the sister-group of the remaining three (Characiphysi), and characiforms are the sister-group of siluroids plus gymnotoids (Siluriformes). Placement of the Gonorynchiformes as the sister-group of the Otophysi is supported by additional evidence. Each of the five lineages is monophyletic. Analysis was concentrated upon species thought to be the least specialized within each lineage; choices of these species are discussed. Chanos is determined to be a relatively primitive gonorynchiform morphologically and the sister-guoup of all other Recent members of the order. Opsariichthys and Zacco are found to be morphologically primitive cypriniforms. We propose that a monophyletic group comprising the Citharinidae and Distichodontidae forms the sister-group of all other characiforms. Within the two families, Xenocharax is the least specialized. We suggest that Hepsetus, the erythrinids, and the ctenoluciids are more derived than the distichodontids and citharinids, and may form a monophyletic group within the characiforms. The traditional hypothesis that Diplomystes is the primitive sister-group of all Recent siluroids is substantiated. Our evidence suggests that Sternopygus is the most primitive gymnotoid morphologically; but rather than being the sister-group of all other gymnotoids, it is the primitive sister-group within a lineage called the Sternopygidae by Mago-Leccia. Previous explanations of otophysan distribution have been based on notions of relationships which are unsupported by the evidence presented herein. Our own analysis of relationships serves primarily to make clear the extent of sympatry, and therefore the probability of dispersal, among the major ostariophysan lineages. The extent of sympatry, together with the widespread distribution of ostariophysans, suggests that the group is older than previously supposed, and our hypotheses of relationships among the characiforms implies that many of the extent characiform lineages evolved before the separation of Africa and South America. Further understanding of ostariophysan distribution must await phylogenetic analysis within each of the five major lineages so that distributiona linked with vicariance patterns and dispersal events can be sorted out.

Zebrin II: A polypeptide antigen expressed selectively by purkinje cells reveals compartments in rat and fish cerebellum

1990-01-22

G. Brochu , Leonard Maler , Richard Hawkes

Abstract Monoclonal antibody mab‐zebrin II was generated against a crude homogenate of cerebellum and electrosensory lateral line lobe from the weakly electric fish Apteronotus leptorhynchus . On Western blots of … Abstract Monoclonal antibody mab‐zebrin II was generated against a crude homogenate of cerebellum and electrosensory lateral line lobe from the weakly electric fish Apteronotus leptorhynchus . On Western blots of fish cerebellar proteins, mab‐zebrin II recognizes a single polypeptide antigen of apparent molecular weight 36 kD. Immunocytochemistry of apteronotid brains reveals that zebrin II immunoreactivity is confined exclusively to Purkinje cells in the corpus cerebelli, lateral valvula cerebelli, and the eminentia granularis anterior. Other Purkinje cells, in the medial valvula cerebelli and eminentia granularis posterior, are not zebrin II immunoreactive. Immunoreactive Purkinje cells are stained completely, including dendrites, axons, and somata. The antigen seems to be absent only from the nucleus. A similar distribution is seen in catfish, goldfish, and a mormyrid fish. Zebrin II immunoreactivity is also found in the rat cerebellum. Western blotting of rat cerebellar proteins reveals a single immunoreactive polypeptide, with apparent, molecular weight 36 kD, as in the fish. Also as in the fish, staining in the adult rat cerebellum is confined to a subset of Purkinje cells. Peroxidase reaction product is deposited throughout the immunoreactive Purkinje cells with the exception of the nucleus. No other cells in the cerebellum express zebrin II. At higher antibody concentrations, a weak glial cross reactivity is seen in most other brain regions: we believe that this is probably nonspecific. Zebrin II + Purkinje cells are clustered together to form roughly parasagittal bands interposed by similar non‐immunoreactive clusters. In all there are 7 zebrin II + and 7 zebrin II − compartments in each hemicerebellum. One immunoreactive band is adjacent to the midline; two others are disposed laterally to each side in the vermis; there is a paravermal band; and finally three more bands are identified in each hemisphere. Both in number and position, these compartments correspond precisely to the bands revealed by using another antibody, mabQ113 (anti‐zebrin I). In both fish and rat the compartmentation revealed by zebrin II immunocytochemistry is related to the organization of cerebellar afferent and efferent projections and may provide clues as to the fundamental architecture of the vertebrate cerebellum.

Evolutionary Strategies and Morphological Innovations: Cichlid Pharyngeal Jaws

1973-12-01

Karel F. Liem

Liem, Karel F. (Museum of Comparative Zoology, Harvard University, Cambridge, Mass. 02138) 1974. Evolutionary strategies and morphological innovations: Cichlid pharyngeal jaws. Syst. Zool. 22:425–441.—The percoid fish family Cichlidae possesses a … Liem, Karel F. (Museum of Comparative Zoology, Harvard University, Cambridge, Mass. 02138) 1974. Evolutionary strategies and morphological innovations: Cichlid pharyngeal jaws. Syst. Zool. 22:425–441.—The percoid fish family Cichlidae possesses a phenomenal ability to colonize lakes and to diversify to an extent unmatched by any other vertebrate family in the presence of predator pressure and strong competition. The invading cichlids successfully occupy contiguous and occasionally overlapping adaptive zones and specialize progressively into diversified subzones, ramifying prodigiously and covering a breadth of total adaptation that would have been entirely unpredictable if we were aware only of the rudiments of the evolutionary process. This evolutionary avalanche can be attributed to the cooccurrence of a wide range of prospective adaptive zones in the lacustrine environment, and the presence of a unique morphological key innovation of maximum versatility. The new adaptive complex has been revealed in this study by electromyographic analysis synchronized with cineradiography of the cichlid pharyngeal jaw apparatus. The morphological novelty characterizing the family Cichlidae involves the development of: a synarthrosis between the lower pharyngeal jaws, a strategic shift of insertion of the two fourth levator externi muscles, and synovial joints between upper pharyngeal jaws and basicranium. This specialized, highly integrated key innovation enables the cichlids not only to transport (deglutination) but also to prepare food, freeing the premaxillary and mandibular jaws to evolve numerous specializations dealing with the collection of dramatically diverse foods. The functional integration of the innovation is so basic and its potential adaptive versatility so rich that it is maintained throughout the adaptive radiation even though numerous nondisruptive evolutionary changes do take place, providing prodigious opportunities for explosive evolution during the exploitation of rich resources of food in the lacustrine environment. The conversion of the preexisting elements into a new and significantly improved cichlid adaptive complex of high selective value may have evolved by rapid steps under influence of strong selection pressure acting on the minor reconstruction of the genotype which is involved in evolutionary changes of the pertinent ontogenetic mechanisms. Such relatively simple evolutionary processes are probably the cause for the general phenomenon that only slight reconstructions of existing structures are necessary for successful and rapid adaptation to drastic shifts of adaptive zones.

Effects of seasonality and fish movement on tropical river food webs

1998-12-01

Kirk O. Winemiller , David B. Jepsen

Tropical rivers and their associated floodplain habitats are dynamic habitat mosaics to which fishes are challenged to respond in an adaptive manner. Migratory fishes create linkages among food webs that … Tropical rivers and their associated floodplain habitats are dynamic habitat mosaics to which fishes are challenged to respond in an adaptive manner. Migratory fishes create linkages among food webs that are partitioned along a nested hierarchy of spatial scales. Such linkages are examined across a hierarchy of spatio‐temporal scales, ranging from small streams to entire drainage basins, for rivers in South America and Africa. Migratory herbivorous fishes originating from eutrophic, productive ecosystems may subsidize resident predators of oligotrophic river ecosystems, which may result in cascading direct and indirect Effects on other species in local food webs. Successful management of many of the most important stocks of tropical river fishes requires conceptual models of how fish movement influences food web structure and dynamics.

Atlantic reef fish biogeography and evolution

2007-10-09

Sergio R. Floeter , Luiz A. Rocha , D. Ross Robertson +7 more

Abstract Aim To understand why and when areas of endemism (provinces) of the tropical Atlantic Ocean were formed, how they relate to each other, and what processes have contributed to … Abstract Aim To understand why and when areas of endemism (provinces) of the tropical Atlantic Ocean were formed, how they relate to each other, and what processes have contributed to faunal enrichment. Location Atlantic Ocean. Methods The distributions of 2605 species of reef fishes were compiled for 25 areas of the Atlantic and southern Africa. Maximum‐parsimony and distance analyses were employed to investigate biogeographical relationships among those areas. A collection of 26 phylogenies of various Atlantic reef fish taxa was used to assess patterns of origin and diversification relative to evolutionary scenarios based on spatio‐temporal sequences of species splitting produced by geological and palaeoceanographic events. We present data on faunal (species and genera) richness, endemism patterns, diversity buildup (i.e. speciation processes), and evaluate the operation of the main biogeographical barriers and/or filters. Results Phylogenetic (proportion of sister species) and distributional (number of shared species) patterns are generally concordant with recognized biogeographical provinces in the Atlantic. The highly uneven distribution of species in certain genera appears to be related to their origin, with highest species richness in areas with the greatest phylogenetic depth. Diversity buildup in Atlantic reef fishes involved (1) diversification within each province, (2) isolation as a result of biogeographical barriers, and (3) stochastic accretion by means of dispersal between provinces. The timing of divergence events is not concordant among taxonomic groups. The three soft (non‐terrestrial) inter‐regional barriers (mid‐Atlantic, Amazon, and Benguela) clearly act as ‘filters’ by restricting dispersal but at the same time allowing occasional crossings that apparently lead to the establishment of new populations and species. Fluctuations in the effectiveness of the filters, combined with ecological differences among provinces, apparently provide a mechanism for much of the recent diversification of reef fishes in the Atlantic. Main conclusions Our data set indicates that both historical events (e.g. Tethys closure) and relatively recent dispersal (with or without further speciation) have had a strong influence on Atlantic tropical marine biodiversity and have contributed to the biogeographical patterns we observe today; however, examples of the latter process outnumber those of the former.

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CHECK LIST OF THE FRESHWATER FISHES OF SOUTH AND CENTRAL AMERICA

2004-08-01

Warren E. Burgess

Ichthyology & Herpetology (formerly Copeia) publishes work on the biology of fishes, amphibians, and reptiles, or work using those organisms as models for testing hypotheses of broad significance. Ichthyology & Herpetology (formerly Copeia) publishes work on the biology of fishes, amphibians, and reptiles, or work using those organisms as models for testing hypotheses of broad significance.

Large‐scale degradation of Amazonian freshwater ecosystems

2015-12-23

Leandro Castello , Márcia N. Macedo

Abstract Hydrological connectivity regulates the structure and function of Amazonian freshwater ecosystems and the provisioning of services that sustain local populations. This connectivity is increasingly being disrupted by the construction … Abstract Hydrological connectivity regulates the structure and function of Amazonian freshwater ecosystems and the provisioning of services that sustain local populations. This connectivity is increasingly being disrupted by the construction of dams, mining, land‐cover changes, and global climate change. This review analyzes these drivers of degradation, evaluates their impacts on hydrological connectivity, and identifies policy deficiencies that hinder freshwater ecosystem protection. There are 154 large hydroelectric dams in operation today, and 21 dams under construction. The current trajectory of dam construction will leave only three free‐flowing tributaries in the next few decades if all 277 planned dams are completed. Land‐cover changes driven by mining, dam and road construction, agriculture and cattle ranching have already affected ~20% of the Basin and up to ~50% of riparian forests in some regions. Global climate change will likely exacerbate these impacts by creating warmer and dryer conditions, with less predictable rainfall and more extreme events (e.g., droughts and floods). The resulting hydrological alterations are rapidly degrading freshwater ecosystems, both independently and via complex feedbacks and synergistic interactions. The ecosystem impacts include biodiversity loss, warmer stream temperatures, stronger and more frequent floodplain fires, and changes to biogeochemical cycles, transport of organic and inorganic materials, and freshwater community structure and function. The impacts also include reductions in water quality, fish yields, and availability of water for navigation, power generation, and human use. This degradation of Amazonian freshwater ecosystems cannot be curbed presently because existing policies are inconsistent across the Basin, ignore cumulative effects, and overlook the hydrological connectivity of freshwater ecosystems. Maintaining the integrity of these freshwater ecosystems requires a basinwide research and policy framework to understand and manage hydrological connectivity across multiple spatial scales and jurisdictional boundaries.

Manual de peixes marinhos do sudeste do Brasil

1977-01-01

José Lima de Figueiredo , Naércio A. Menezes

Todas as outras são marinhas, mas algumas espécies de peixe-serra (Família Pristidae) entram nos grandes rios, como é o caso de Pristis perotteti no Rio Amazonas.De modo geral, as raias Todas as outras são marinhas, mas algumas espécies de peixe-serra (Família Pristidae) entram nos grandes rios, como é o caso de Pristis perotteti no Rio Amazonas.De modo geral, as raias

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Checklist of catfishes, recent and fossil (Osteichthyes: Siluriformes), and catalogue of siluriform primary types

2007-03-08

Carl J. Ferraris

A checklist of Recent and fossil catfishes (Order Siluriformes) is presented, summarizing taxonomic literature published through 2005. From 4624 nominal species group names and 810 genus group names, 3093 species … A checklist of Recent and fossil catfishes (Order Siluriformes) is presented, summarizing taxonomic literature published through 2005. From 4624 nominal species group names and 810 genus group names, 3093 species are recognized as valid, and are distributed among 478 genera and 36 families. Distributional summaries are provided for each species, and nomenclatural synonymies, including relevant information on all name-bearing types, are included for all taxa. One new name is proposed herein: Clariallabes teugelsi, as a replacement for Clarias (Allabenchelys) dumerili longibarbis David & Poll, 1937, which is preoccupied by Clarias longibarbis Worthington, 1933, but has been treated as a valid species of Clariallabes by Teugels. Acrochordonichthys melanogaster Bleeker, 1854, is designated as type species of Acrochordonichthys Bleeker, 1857, inasmuch as no earlier valid designation has been found. A new genus Pseudobagarius, is proposed for the “pseudobagarius group” of species formerly placed in Akysis. The status of 228 species group names remains unresolved and 31 names based on otoliths ascribed to catfishes are listed but not placed into the checklist. The current emphasis given to catfish taxonomy at present is likely to result in a dramatic increase in the total number of valid taxa as well as major changes in the membership of some of the higher level taxa recognized here.

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On the Function and Evolution of Electric Organs in Fish

1958-03-01

H. W. Lissmann

ABSTRACT The electric discharges of Gymnarchus niloticus and of representative species of seven genera of the Mormyridae have been examined in their natural habitat in Africa and in the laboratory. … ABSTRACT The electric discharges of Gymnarchus niloticus and of representative species of seven genera of the Mormyridae have been examined in their natural habitat in Africa and in the laboratory. Comparable investigations of the South American Gymnotidae have shown the existence of two discharge types in both these unrelated fish families. The first type of electric discharge consists of very regular sequences of continuously emitted, monophasic pulses, varying from species to species in frequency, and within narrower limits from individual to individual. Fish emitting this first type of pulses include Gymnarchus, Hypopomus and Eigenmannia. The frequency range for these fish lies between 60 and 400 discharges/sec. The frequency does not alter with the state of excitation of the fish. The duration of individual pulses is relatively long, i.e. 2–10 msec. The second type of discharge is less regular in frequency, the pulse duration much shorter and the pulse shape more complex. The individual discharge from the whole electric organ lasts about 0.2 msec, in Petrocephalus. This type of discharge is found in all the examined species of the Mormyridae and in such forms as Gymnotus carapo and Staetogenes elegans. The basic discharge rate of a resting mormyrid is somewhat variable and not strictly rhythmical. It usually lies between 1 and 6 pulses/sec. Stimuli which excite the mormyrids cause an increase in the discharge frequency. The recorded maximum is about 130 pulses/sec. Suitable stimuli can inhibit the discharges of the Mormyridae for prolonged periods. In Gymnotus carapo and Staetogenes elegans the basic discharge rate is higher and of regular rhythmicity. Depending on temperature the frequencies lie between 30 and 87 pulses/sec. When these fish are excited the frequencies are increased up to 200 pulses/sec, for a short time. The shape of the electric field, which is set up with each pulse around the fish, has been examined. A theory has been proposed which suggests that these fish, by means of their electric pulses, can locate objects if their electrical conductivity differs from that of water. These fish have shown themselves extremely sensitive to influences affecting the electric field. This has been studied by applying artificial electric stimuli, by studying the effects of conductors and non-conductors introduced into the field, and the reactions towards magnetic fields and electrostatic charges. Conditioned reflex experiments with Gymnarchus niloticus and Gymnotus carapo have shown that these fish can detect the presence of a stationary magnet, and that they can discriminate between conductors and non-conductors. The prey of these fish does not appear to be affected by the discharges. Inter alia, the electric pulses have a social significance. This locating mechanism may be considered as an adaptation to life in turbid water. Gymnotidae and Mormyridae (taken to include Gymnarchus) show striking features of convergent evolution. Unusual locomotory adaptations such as swimming by means of the dorsal fin (Gymnarchus), the anal fin (Gymnotidae) and ‘Gemminger‘s bones’ (Mormyridae) may be considered as a means which tends to make the axis of symmetry of the fish and of its electric field coincide during active movements. A new theory for the evolution of electric organs has been suggested. A major prerequisite appears to be a receptor sensitive to electrical stimulation. It is suggested that special sensory and nervous differentiations of the lateralis system (‘mormyromasts’, valvulae cerebelli) are concerned with the perception and integration of electric stimuli. Muscular action potentials have been recorded in the water at some distance from non-electric fish. The easiest explanation for the evolution of strong electric organs would appear to start from such muscular action potentials, and proceed via weak electric organs used for orientation, to the powerful offensive and defensive electric organs."

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Fish biodiversity and conservation in South America

2016-06-17

Roberto Esser dos Reis , James S. Albert , Fabio Di Dario +3 more

The freshwater and marine fish faunas of South America are the most diverse on Earth, with current species richness estimates standing above 9100 species. In addition, over the last decade … The freshwater and marine fish faunas of South America are the most diverse on Earth, with current species richness estimates standing above 9100 species. In addition, over the last decade at least 100 species were described every year. There are currently about 5160 freshwater fish species, and the estimate for the freshwater fish fauna alone points to a final diversity between 8000 and 9000 species. South America also has c. 4000 species of marine fishes. The mega-diverse fish faunas of South America evolved over a period of >100 million years, with most lineages tracing origins to Gondwana and the adjacent Tethys Sea. This high diversity was in part maintained by escaping the mass extinctions and biotic turnovers associated with Cenozoic climate cooling, the formation of boreal and temperate zones at high latitudes and aridification in many places at equatorial latitudes. The fresh waters of the continent are divided into 13 basin complexes, large basins consolidated as a single unit plus historically connected adjacent coastal drainages, and smaller coastal basins grouped together on the basis of biogeographic criteria. Species diversity, endemism, noteworthy groups and state of knowledge of each basin complex are described. Marine habitats around South America, both coastal and oceanic, are also described in terms of fish diversity, endemism and state of knowledge. Because of extensive land use changes, hydroelectric damming, water divergence for irrigation, urbanization, sedimentation and overfishing 4-10% of all fish species in South America face some degree of extinction risk, mainly due to habitat loss and degradation. These figures suggest that the conservation status of South American freshwater fish faunas is better than in most other regions of the world, but the marine fishes are as threatened as elsewhere. Conserving the remarkable aquatic habitats and fishes of South America is a growing challenge in face of the rapid anthropogenic changes of the 21st century, and deserves attention from conservationists and policy makers.

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Whole-genome sequences of Malawi cichlids reveal multiple radiations interconnected by gene flow

2018-11-19

Milan Malinsky , Hannes Svardal , Alexandra M. Tyers +4 more

Abstract The hundreds of cichlid fish species in Lake Malawi constitute the most extensive recent vertebrate adaptive radiation. Here we characterize its genomic diversity by sequencing 134 individuals covering 73 … Abstract The hundreds of cichlid fish species in Lake Malawi constitute the most extensive recent vertebrate adaptive radiation. Here we characterize its genomic diversity by sequencing 134 individuals covering 73 species across all major lineages. The average sequence divergence between species pairs is only 0.1–0.25%. These divergence values overlap diversity within species, with 82% of heterozygosity shared between species. Phylogenetic analyses suggest that diversification initially proceeded by serial branching from a generalist Astatotilapia -like ancestor. However, no single species tree adequately represents all species relationships, with evidence for substantial gene flow at multiple times. Common signatures of selection on visual and oxygen transport genes shared by distantly related deep-water species point to both adaptive introgression and independent selection. These findings enhance our understanding of genomic processes underlying rapid species diversification, and provide a platform for future genetic analysis of the Malawi radiation.

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Freshwater fishes of Mexico

2006-07-01

Robert Rush Miller , W. L. Minckley , Steven M. Norris

Though is only one-fifth the size of the continental United States, it is home to nearly two-thirds as many freshwater fishes as those that swim the waters of the United … Though is only one-fifth the size of the continental United States, it is home to nearly two-thirds as many freshwater fishes as those that swim the waters of the United States and Canada combined. Mexico's diverse freshwater fauna can be attributed to the country's highly varied physical geography, a wide latitudinal range, the largest river system in middle America, and, ironically, its oceans many marine groups left the brine for the inland springs and never returned to the sea. No one knew these Mexican freshwaters or the fish that inhabit them better than the late world-renowned ichthyologist Robert Rush Miller. A pioneer of the field, Miller undertook his first field excursion more than fifty years ago and, in the decades following, amassed the information necessary to write the first encyclopedia of Mexican inland ichthyology. Providing keys to more than 500 native species accompanied by detailed distribution maps and illustrations Freshwater Fishes of Mexico offers a historical overview of the country's ichthyology, as well as syntheses of the unique biogeography of Mexican fishes and their current conservation status. Organized by family, the species accounts are supplemented with color galleries containing photographs of live fishes in their native environments and natural habitats. Exploring ecological, biological, and taxonomic issues, the book also considers the evolutionary history of the ichthyofauna itself and the human history of the scientists who researched it during the last several centuries. The life's work of Robert Rush Miller, the long-awaited Freshwater Fishes of Mexico will be welcomed not only by students of Mexican fishes, but by all ichthyologists working in Central and North America. This book will also find an audience among home aquarium hobbyists, fishery managers, conservation biologists, and environmental planners and managers.

ZUEC-AMP - Coleção de Anfíbios do Museu de Zoologia da UNICAMP

2024-01-01

Luı́s Felipe Toledo

A coleção de anfíbios do ZUEC constitiu-se principalmente de animais do Brasil, mas também possui exemplares da Ásia, África, América do Norte, América Central e outros países da América do … A coleção de anfíbios do ZUEC constitiu-se principalmente de animais do Brasil, mas também possui exemplares da Ásia, África, América do Norte, América Central e outros países da América do Sul. Os 23.400 lotes da coleção incluem 3 ordens, 50 famílias, 180 gêneros e aproximadamente 500 espécies. Tais lotes estão divididos entre: ninhos, óvulos, desovas, girinos, animais diafanizados, holótipos, parátipos, e indivíduos adultos.

Museu Paraense Emílio Goeldi - Mastozoology Collection

2023-01-01

José de Sousa e Silva Júnior

The Mastozoology collection of the Museu Paraense Emílio Goeldi has over 41,000 records. The Mastozoology collection of the Museu Paraense Emílio Goeldi has over 41,000 records.

The Amazon and its main affluents: Hydrography, morphology of the river courses, and river types

1984-01-01

Harald Sioli

Ficha de Aleuron carinata

2025-06-24

Felipe Wanderley Amorim , Alexandre Soares , Amabílio José Aires de Camargo +3 more | Datasets - Sistema SALVE - ICMBio

REVISÃO SOBRE A ESPÉCIE Dipteryx Alata Vogel: POTENCIAL DE USO E ASPECTOS SILVICULTURAIS

2025-06-24

Wislan Pereira Leão , Argel Costa Souza , Gabriele Silva Gomes +3 more | Aracê.

Dipteryx alata Vogel (baru) is a native species of the Brazilian Cerrado with high socioeconomic, nutritional and environmental potential. However, despite its wide distribution and regional importance, technical-scientific information on … Dipteryx alata Vogel (baru) is a native species of the Brazilian Cerrado with high socioeconomic, nutritional and environmental potential. However, despite its wide distribution and regional importance, technical-scientific information on the silvicultural, ecological and technological aspects of the species is still scarce and scattered, limiting its adoption in reforestation programs, agroextractivism and sustainable production chains. This study aimed to gather, organize and systematize the knowledge available in the literature on the main aspects related to the cultivation, management, potential uses and challenges associated with the exploitation of D. alata. For this, a comprehensive bibliographic review was carried out, using scientific databases, books and technical documents, addressing national and international publications. The results demonstrate that baru has high adaptability to different edaphoclimatic conditions, standing out for its ecological importance in the conservation of biodiversity and for the production of fruits with high nutritional and commercial value. Technological advances in the processing, storage and use of waste, including the production of solid biofuels, were also identified. However, there are still gaps in knowledge about silvicultural practices, genetic improvement and economic viability in commercial plantations, especially in regions such as Maranhão. It is concluded that baru has great potential to be integrated into environmental recovery and income generation programs in agroextractive communities, requiring the intensification of applied research and the development of public policies that encourage its production and sustainable management.

Ficha de Aellopos tantalus

2025-06-24

Felipe Wanderley Amorim , Alexandre Soares , Amabílio José Aires de Camargo +3 more | Datasets - Sistema SALVE - ICMBio

AVALIAÇÃO DE TÉCNICAS COMPENSATÓRIAS PARA ATENUAÇÃO DE ALAGAMENTOS NA SUB-BACIA DA LAGOA RODRIGO DE FREITAS

2025-06-23

Rodrigo dos Santos Barbosa , Júlio César da Silva , Lúcio Silva de Souza +1 more | Revista Contemporânea

O problema das inundações e dos alagamentos está a tornar-se cada vez mais recorrente nos centros urbanos. O processo de urbanização das cidades promoveu modificações no uso e ocupação do … O problema das inundações e dos alagamentos está a tornar-se cada vez mais recorrente nos centros urbanos. O processo de urbanização das cidades promoveu modificações no uso e ocupação do solo, dificultando que a água permeie, causando tais eventos e situações de risco para a população e causar prejuízos. A sub-bacia da Lagoa Rodrigo de Freitas é uma região de grande importância econômica para a cidade do Rio de Janeiro e de grande interesse imobiliário. O seu processo de ocupação foi, em alguns momentos da história, carente de planeamento e, noutros, bastante acelerado e expansionista, tendo impacto na dinâmica e gestão das águas pluviais atualmente. Para essa região, foram também coletados (bibliográficos, geográficos e hidrográficos). No material bibliográfico foram abordados relatórios, trabalhos acadêmicos e manuais técnicos, passando por uma triagem em seguida. Os dados científicos foram tratados, calculados e gerados em gráficos no Excel para avaliação da intensidade de chuva em relação ao tempo. No QGIS, foi realizado todo o trabalho de SIG e geração de mapas temáticos da região. O presente trabalho identifica áreas com histórico de ocorrências, caracteriza e indica espaços públicos com potencial para receber algumas técnicas compensatórias.

Situación reproductiva del Flamenco Chileno (Phoenicopterus chilensis) en el Perú

2025-06-23

Enver Ortiz , Pablo Martínez , F.J. Suárez +5 more | El Hornero

El Flamenco Chileno o Austral (Phoenicopterus chilensis) o conocido localmente como Parihuana, Pariona o Paruela se distribuye principalmente en el Perú a lo largo de lagos, lagunas y humedales altoandinos … El Flamenco Chileno o Austral (Phoenicopterus chilensis) o conocido localmente como Parihuana, Pariona o Paruela se distribuye principalmente en el Perú a lo largo de lagos, lagunas y humedales altoandinos desde el lago Titicaca (Puno) hasta el lago Junín o Chinchaycocha (Junín), mientras que en la zona costera desde los humedales de Ite (Tacna) hasta los manglares de Tumbes, frontera con Ecuador. En este trabajo, reportamos cinco localidades como sitios reproductivos históricos, así como recientes donde se han reportado eventos reproductivos del Flamenco Chileno. Primero, en los humedales de Ite, segundo en la laguna Salinas (Arequipa), tercero en la laguna Yaurihuiri (Ayacucho), cuarto el lago Junín y el quinto y más importante en la laguna La Niña (Piura) este último lugar con una abundancia de cerca de 15.000 individuos y hasta de 7.000 polluelos, considerándosele actualmente como el principal núcleo reproductivo de la especie en el Perú y el más septentrional en toda la distribución de la especie.

Impact of magnetic fields on the early ontogeny of the jaguar cichlid Parachromis managuensis Günther, 1867 and the green terror Andinoacara rivulatus Günther, 1860

2025-06-23

Radosław Piesiewicz , Jan Krzystolik , Krzysztof Formicki | The European Zoological Journal

Ficha de Chilodus gracilis

2025-06-23

André Luiz Netto Ferreira , Bruno Francelino de Melo , Bruno Stefany Feitoza Barros +7 more | Datasets - Sistema SALVE - ICMBio

Gill evolution in Neotropical electric fishes: Comparative phylogenetic evidence for hypoxia‐driven adaptation

2025-06-22

William G. R. Crampton , Leilani B. Pathak , Francesco H. Janzen +2 more | Functional Ecology

Abstract Tropical freshwater fishes are often exposed to hypoxia, which limits aerobic metabolism and drives the evolution of diverse physiological, behavioural and morphological adaptations. In species from chronically hypoxic habitats, … Abstract Tropical freshwater fishes are often exposed to hypoxia, which limits aerobic metabolism and drives the evolution of diverse physiological, behavioural and morphological adaptations. In species from chronically hypoxic habitats, gill morphology is frequently modified through traits that increase branchial surface area. However, the adaptive basis of these traits and the evolutionary origins of hypoxia tolerance remain poorly understood, partly because few studies have examined species‐rich clades in a phylogenetic context. The Neotropical electric knifefish family Hypopomidae, which inhabits environments with a broad range of dissolved oxygen (DO) conditions, represents an ideal model for examining respiratory adaptations to DO variability. Using phylogenetic comparative methods, we examined correlations between environmental DO and gill morphology in 27 species, focussing on three independently varying traits associated with branchial surface area: mean filament length (MFL), mean hemibranch length (MHL) and total filament number (TFN). Species specialized to hypoxic habitats exhibited significantly greater MFL (but not MHL or TFN) after phylogenetic corrections, supporting an adaptive basis for increased gill filament length. In contrast, species specialized to normoxic habitats had lower MFL, likely reflecting trade‐offs involving the energetic costs of gill development, functional constraints from adjacent morphological structures or physiological limitations. Many hypopomid species are eurytopic, with demes inhabiting both normoxic and hypoxic habitats. Like species specialized to hypoxic systems, hypoxia‐tolerant demes exhibit elevated MFL, but not MHL or TFN, suggesting a shared pathway for hypoxia tolerance across different evolutionary scales. Ancestral state reconstructions indicate that ancestors with lower MFL occupied normoxic environments, whereas those with elevated MFL likely evolved in hypoxic systems. A marked transition to greater MFL, accompanied by a simultaneous shift in ancestral habitat, occurs at the base of the Brachyhypopomus beebei group. The emergence of hypoxia tolerance and the onset of diversification in the B. beebei group occurred approximately 4 Ma, coincident with a Pliocene expansion of seasonally hypoxic Amazon whitewater floodplains—likely driven by increased Andean sedimentation during the Amazon's transition to its modern transcontinental course. Our findings highlight how environmental changes shaped by ancient geological events can drive ecomorphological innovation, potentially accelerating species diversification. Read the free Plain Language Summary for this article on the Journal blog.

Elucidating aspects of the life-history traits of small electric knifefish from the Eastern Amazon streams

2025-06-20

Nathalia C. López-Rodríguez , Érica Pellegrini Caramaschi , Bruno da Silveira Prudente +1 more | Environmental Biology of Fishes

Re‐describing and ascertaining to homeland <scp>Hypostomus vaillanti</scp> (<scp>S</scp>teindachner, 1877) (<scp>S</scp>iluriformes: <scp>L</scp>oricariidae), a golden and black pleco from <scp>N</scp>ortheast <scp>B</scp>razil

2025-06-18

Cláudio Henrique Zawadzki , Iago de Souza Penido , Silvia Yasmin Lustosa Costa +1 more | Journal of Fish Biology

Abstract Approximately 26 species of Hypostomus occur in the five freshwater ecoregions in Northeast Brazil. One of these ecoregions is the Parnaíba, which drains almost the entire state of Piauí, … Abstract Approximately 26 species of Hypostomus occur in the five freshwater ecoregions in Northeast Brazil. One of these ecoregions is the Parnaíba, which drains almost the entire state of Piauí, and part of the states of Maranhão and Ceará. Among the species of Hypostomus registered in this ecoregion, there is Hypostomus vaillanti . The type locality of H. vaillanti was assigned to the Rio Preto, a tributary of the median portion of the Rio São Francisco basin at the municipality of Villa de Santa Rita (currently Santa Rita de Cássia), Bahia State, Brazil. Despite these historical data, we only found H. vaillanti in the Rio Parnaíba basin. Some fish surveys were carried out in different times by the authors and by other skilled ichthyologists in the Rio Preto and other nearby rivers from the Rio São Francisco basin, and no specimen of H. vaillanti have been found. Additionally, although the original description of H. vaillanti was well written, searching its distinction from some congeners in the taxonomic literature is nowadays quite complicated. Therefore, this species is re‐described, and a new diagnosis is provided based on the analysis of recently found specimens in addition to an analysis of the type material. A lectotype of the Plecostomus vaillanti is designated herein. The results suggest that the distribution of H. vaillanti is restricted to the Rio Parnaíba basin; furthermore, we provide a molecular phylogenetic analysis that highlights some relationships between H. vaillanti and closely related species.

Captura de organismos ornamentais: contextos e dinâmicas em Santarém

2025-06-18

Gabriele Santos de Almeida , Elizangela Sant’Anna da Silva , Ana Paula Monschau Funck +1 more | Brazilian Journal of Development

O potencial para a produção de peixes ornamentais cresce anualmente no Brasil devido à grande diversidade de espécies ornamentais já catalogadas, tendo a indústria do aquarismo brasileiro uma grande importância … O potencial para a produção de peixes ornamentais cresce anualmente no Brasil devido à grande diversidade de espécies ornamentais já catalogadas, tendo a indústria do aquarismo brasileiro uma grande importância no mundo. Também é conhecido que a bacia amazônica é o celeiro das espécies de peixes ornamentais do Brasil, consequentemente o estado do Pará é favorecido em termos de recursos hídricos e diversidade de espécies de vertebrados como os peixes. No entanto, estudos relacionados aos organismos aquáticos ornamentais são escassos, há dados subestimados afetando esta atividade gerando como consequência perdas para os produtores. Estes fatores contribuem para dificultar ações de incentivo à atividade. Assim, os estudos oficiais como o levantamento de demanda impossibilitam conhecer a importância deste agronegócio. Considerando estes fatores supracitados este estudo teve o objetivo geral de identificar a logística das capturas realizadas pelos aquariofilistas de Santarém, região Oeste do Estado do Pará utilizando a técnica de amostragem snowball e questionários enviados via google formulários com perguntas abertas e fechadas. Os resultados desta pesquisa mostraram que nesta região os homens representam a maioria dos aquariofilistas possuindo ensino médio e/ou ensino médio técnico e utilizando diversas artes de pesca que são ativas para capturar vertebrados e invertebrados ornamentais que possuem hábitos noturnos e diurnos tanto em rio de água clara e preta.

Ficha de Kinnapotiguara troglobia

2025-06-17

Diego de Medeiros Bento , Marconi Souza‐Silva , Maria Elina Bichuette +1 more | Datasets - Sistema SALVE - ICMBio

Ficha de Tangara cyanocephala cearensis

2025-06-17

Helder Farias Pereira de Araújo , Alexandre M. Fernandes , Antônio Emanuel Barreto Alves de Sousa +7 more | Datasets - Sistema SALVE - ICMBio

Ficha de Charinus caatingae

2025-06-17

Ana Caroline Oliveira Vasconcelos , Alessandro Ponce de Leão Giupponi , Diego de Medeiros Bento +2 more | Datasets - Sistema SALVE - ICMBio

Ficha de Brasileirinho cavaticus

2025-06-17

Rodrigo Lopes Ferreira , Rafaela Bastos‐Pereira , Marconi Souza‐Silva +2 more | Datasets - Sistema SALVE - ICMBio

Trophic organization of the fish assemblage in a subtropical coastal freshwater lagoon

2025-06-17

Sunshine de Ávila-Simas , Sarah Carvalho Sticca , David Augusto Reynalte‐Tataje +1 more | Studies on Neotropical Fauna and Environment

ESTUDO RETROSPECTIVO DE FRATURAS EM GAMBÁS-DE-ORELHA-BRANCA (Didelphis albiventris) ATENDIDOS NO HOSPITAL VETERINÁRIO DA UNESP, CAMPUS DE BOTUCATU, NO PERÍODO DE 2020 A 2024

2025-06-16

Juliana Pontes Tribucci , Bruno Cesar Schimming | Nucleus Animalium

Devido à proximidade dos centros urbanos com as áreas florestais, o contato entre seres humanos e a fauna silvestre, especialmente os marsupiais, é cada vez mais intensificado. Visto isso, animais … Devido à proximidade dos centros urbanos com as áreas florestais, o contato entre seres humanos e a fauna silvestre, especialmente os marsupiais, é cada vez mais intensificado. Visto isso, animais selvagens, como o gambá-de-orelha-branca, são cada vez mais atendidos nos centros veterinários. Assim, o objetivo deste estudo foi relatar a casuística de fraturas e luxações dessa espécie atendida no Hospital Veterinário, FMVZ, UNESP, campus de Botucatu, durante os anos 2020 a 2024. Até o momento, foi realizado um estudo retrospectivo das fichas cadastrais e radiografias desses marsupiais atendidos de 2020 a 2022. Essa análise evidenciou que de 50 animais cadastrados nesse período, 22 apresentavam fraturas (44%), sendo a maioria dos casos ocorridos durante o inverno e a primavera, sendo 8 ocorrências (36,4%) em cada uma das estações citadas. O estudo demonstra que a principal origem das fraturas foi ataque de cão, 7 casos (32%). Em relação à localização, o conjunto de ossos mais acometido foi o crânio, 14 fraturas (35%), seguido pela coluna vertebral, 11 (27,5%). Dessa forma, sugere-se que a casuística das fraturas em gambás-de-orelha branca seja maior na primavera e no inverno devido a ataques de cães, que resultaram em fraturas cranianas, majoritariamente.

QUALIDADE SANITÁRIA DA ÁGUA POTÁVEL EM PALMAS-TOCANTINS: AVALIAÇÃO MICROBIOLÓGICA E PARASITOLÓGICA POR MACROREGIÃO

2025-06-16

Kelly Rejane de Oliveira Araújo , M Silva , Sinara de Fátima Freire dos Santos +1 more | Revista fisio&terapia.

Este estudo teve como objetivo avaliar a qualidade sanitária da água potável distribuída nas quatro macroregiões da cidade de Palmas, Tocantins, durante o período de 2024 a 2025, com enfoque … Este estudo teve como objetivo avaliar a qualidade sanitária da água potável distribuída nas quatro macroregiões da cidade de Palmas, Tocantins, durante o período de 2024 a 2025, com enfoque na caracterização microbiológica e parasitológica. As amostras de água foram coletadas em diferentes pontos de abastecimento urbano e submetidas a análises laboratoriais padronizadas. A investigação microbiológica incluiu a detecção de coliformes totais e termotolerantes, especialmente Escherichia coli, indicadores clássicos de contaminação fecal e falhas no processo de desinfecção. Paralelamente, as análises parasitológicas foram realizadas por meio do método de sedimentação espontânea em tubo cônico, visando a identificação de estruturas como cistos, oocistos, ovos e larvas de parasitas com potencial patogênico, como Giardia spp., Cryptosporidium spp., Ascaris lumbricoides e Ancylostoma spp. Além dos dados laboratoriais, foram consideradas informações complementares de órgãos oficiais, como o Ministério da Saúde, para contextualização dos achados em relação às normas de potabilidade estabelecidas pela legislação vigente (Portaria GM/MS nº 888/2021). Os resultados demonstraram variações na qualidade da água entre as macroregiões analisadas, com presença de microrganismos patogênicos em amostras que, teoricamente, estariam aptas para o consumo humano. Tais achados apontam para possíveis falhas no sistema de abastecimento e/ou contaminação secundária durante o armazenamento doméstico. Conclui-se que a vigilância da qualidade da água deve ser contínua, abrangente e integrada às ações de saúde pública e educação sanitária, a fim de prevenir surtos de doenças de veiculação hídrica e assegurar o direito à água potável segura para toda a população palmense.

Diagnóstico da fauna recebida no CETRAS de Caldas Novas, Goiás, Brasil central

2025-06-15

Rosalinda dos Santos Damasceno Carvalho , Wellington Hannibal | Scientia Plena

Animais encontrados em situações de atropelamento, ferimentos ou filhotes que caem de seus ninhos, são resgatados e encaminhados para os Centros de Triagem e Reabilitação de Animais Silvestres (CETRAS). Neste … Animais encontrados em situações de atropelamento, ferimentos ou filhotes que caem de seus ninhos, são resgatados e encaminhados para os Centros de Triagem e Reabilitação de Animais Silvestres (CETRAS). Neste estudo, analisamos a fauna silvestre recebida no CETRAS de Caldas Novas, no Brasil central, entre 2022 e 2023. Acessamos as fichas de entrada de cada espécime recebido no CETRAS e registramos dados como data de entrada, tipo de entrega, agente responsável, táxon e tempo de permanência no centro. Um total de 447 animais, pertencentes a 80 espécies de vertebrados foi recebido. Aves foi o grupo mais representativo com 303 animais, pertencentes a 50 espécies, seguido por mamíferos (81 recebidos dentre 16 espécies) e répteis (63 recebimentos de 14 espécies). Três espécies de psitacídeos (arara-canindé, periquito-de-encontro-amarelo e periquitão) apresentaram danos nas asas, tórax, bico e pernas. Gambás e jabutis com algum tipo de injúria apresentaram danos no tórax e membros, e nas patas e carapaça, respectivamente. Os resgates desses animais foram realizados em grande parte em áreas urbanas. Este estudo oferece uma visão abrangente das dinâmicas e dos desafios enfrentados pela fauna silvestre.

High‐frequency electrical tuning and linear filter properties of Knollenorgan electroreceptors of mormyrid electric fish

2025-06-15

Indira M. Raman , Carl D. Hopkins | The Journal of Physiology

Abstract Electrical tuning allows auditory, vestibular, and electrosensory receptor cells to filter sensory signals and selectively transmit specific stimulus frequencies. In auditory hair cells, electrical tuning results from membrane potential … Abstract Electrical tuning allows auditory, vestibular, and electrosensory receptor cells to filter sensory signals and selectively transmit specific stimulus frequencies. In auditory hair cells, electrical tuning results from membrane potential resonance produced by voltage‐gated Ca and K(Ca) channels, with variable kinetics that generate different tuning properties. Such resonance has been observed only up to ∼1 kHz, however. Additionally, in most species that employ electrical tuning, hearing is constrained to this relatively low‐frequency range, raising the question of whether electrical tuning can extend to higher frequencies. Here we investigated this possibility by studying tuning and transduction properties of Knollenorgans, a class of tuberous electroreceptors of mormyrid electric fish. These organs, which generate spike‐like receptor potentials, detect species‐specific electric organ discharges (EODs). To test whether fish with brief EODs had correspondingly high‐frequency electrical tuning, we recorded tuning curves from Knollenorgans of three species, Brevimyrus niger, Gnathonemus petersii , and Pollimyrus adspersus , which have EODs with spectral components exceeding 5 kHz. All species had receptors tuned to a range of frequencies tiling the species‐specific EOD spectrum, with best frequencies extending beyond 10 kHz in P. adspersus . We also computed the impulse response of each Knollenorgan by reverse‐correlating spikes elicited by white noise stimuli. After incorporation of a spike threshold non‐linearity, convolving the impulse response with arbitrary stimulus waveforms successfully predicted spike patterns experimentally evoked by these inputs. These analyses demonstrate that differential electrical tuning properties of Knollenorgans produce distinct, well‐timed spike responses that reliably encode time‐varying electrical signals at frequencies up to 20 kHz. image Key points Knollenorgans, among the tuberous electroreceptors of mormyrid electric fish, are modified hair cells that transduce electrical signals into spike‐like receptor potentials. Knollenorgans in three species of mormyrids are tuned to frequencies matched to the frequencies present in the species‐typical electric organ discharges, suiting them for electric communication. The frequency of highest sensitivity of Knollenorgans can extend well beyond 10 kHz, far exceeding the limit for electrical tuning mechanisms estimated from mechanosensitive hair cells. The timing and probability of spiking by Knollenorgans are accurately predicted by a model composed of linear filtering followed by non‐linear rectification and spike thresholding. Differential filtering by different Knollenorgans produces distinct outputs to the same input, with high‐tuned receptors effectively transmitting well‐timed spikes, on a microsecond time scale, in response to electrical stimuli up to 20 kHz.

Ficha de Prionobrama filigera

2025-06-13

André Luiz Henriques Esguícero , André Luiz Netto Ferreira , Bruno Francelino de Melo +7 more | Datasets - Sistema SALVE - ICMBio

Ficha de Brycon melanopterus

2025-06-13

André Luiz Henriques Esguícero , André Luiz Netto Ferreira , Bruno Francelino de Melo +7 more | Datasets - Sistema SALVE - ICMBio

Ficha de Roeboexodon guyanensis

2025-06-13

André Luiz Henriques Esguícero , André Luiz Netto Ferreira , Bruno Francelino de Melo +7 more | Datasets - Sistema SALVE - ICMBio

Ficha de Prodontocharax alleni

2025-06-13

André Luiz Henriques Esguícero , André Luiz Netto Ferreira , Bruno Francelino de Melo +7 more | Datasets - Sistema SALVE - ICMBio

BIOSSORÇÃO DE COBRE EM AGUARDENTE UTILIZANDO CASCAS E SEMENTES DE Mouriri guianensis (CRIVIRI)

2025-06-13

Juliano Cordeiro , Ana M. B. Nunes , Lorena Sakamoto Dutra +5 more | Editora e-Publicar eBooks

Aspectos da pesca artesanal na ilha do Risco, Município de Itacoatiara, Amazonas, Brasil

2025-06-13

Thiago Marinho-Pereira , Charles Hanry Faria , Lian Valente Brandão +1 more | OBSERVATÓRIO DE LA ECONOMÍA LATINOAMERICANA

O objetivo deste estudo foi caracterizar a pesca artesanal na Ilha do Risco, município de Itacoatiara, Amazonas, Brasil, destacando sua importância socioeconômica e cultural para as comunidades ribeirinhas. Foram entrevistados … O objetivo deste estudo foi caracterizar a pesca artesanal na Ilha do Risco, município de Itacoatiara, Amazonas, Brasil, destacando sua importância socioeconômica e cultural para as comunidades ribeirinhas. Foram entrevistados 24 pescadores, revelando que a atividade é essencial para subsistência e renda, com 66,7% dos entrevistados dependendo exclusivamente da pesca. A produção mensal variou de 400 kg a 5.600 kg por pescador, com Captura por Unidade de Esforço (CPUE) média de 47,8 kg (pescador.dia)-1. As espécies mais relatadas pelos pescadores entrevistados foram o pacu (Mylossoma duriventre) e o dourado (Brachyplatystoma flavicans). A pesca é realizada principalmente em embarcações como canoas de madeira e botes de alumínio, utilizando apetrechos como malhadeiras e redes de arrasto. Os principais desafios incluem poluição ambiental, desvalorização do pescado, fluxo de navios e falta de políticas públicas. O estudo evidencia a necessidade de gestão sustentável e inclusiva para preservar os recursos pesqueiros e melhorar as condições de vida das comunidades locais.

DIET, WEIGHT-LENGTH RELATIONSHIP AND HABITAT USE OF PIABINA ARGENTEA REINHARDT 1867 IN A NEOTROPICAL RIVER

2025-06-12

Julia Fernanda de Camargo Teles Miranda , Talita Rolim de Freitas Lima , Thiago Mündel Ribeiro Santos +3 more | Oecologia Australis

Piabina argentea é um peixe caracídeo de pequeno porte com ampla distribuição pela América do Sul, incluindo nas bacias do Alto Paraná e São Francisco. Este estudo disponibiliza informações relevantes … Piabina argentea é um peixe caracídeo de pequeno porte com ampla distribuição pela América do Sul, incluindo nas bacias do Alto Paraná e São Francisco. Este estudo disponibiliza informações relevantes sobre a ecologia da espécie, incluindo dieta, estrutura populacional e uso de habitat. O estudo foi conduzido em um rio neotropical localizado na Floresta Nacional de Ipanema, SP, Brasil. A espécie ocorreu em trechos mais estreitos e profundos de substratos lodoso ou rochoso do rio, estando ausente nos trechos mais largos e rasos. Ao todo, foram capturados e analisados 125 espécimes com comprimento padrão variando de 2,5 cm a 5,5 cm. A população estudada apresentou alta frequência de indivíduos de maior porte e crescimento alométrico negativo (b = 2,83) e uma dieta herbívora, composta principalmente por algas filamentosas ou euglenófitas. A maior parte das classes de tamanho consumiu predominantemente algas, mas os indivíduos maiores consumiram predominantemente fragmentos de insetos. Nossos resultados permitem entender melhor os atributos ecológicos da espécie relacionados à sua distribuição.

Introgression dynamics of sex-linked chromosomal inversions shape the Malawi cichlid radiation

2025-06-12

Moritz Blumer , Valentina Burskaia , I. V. Artyushin +7 more | Science

Chromosomal inversions can contribute to adaptive speciation by linking coadapted alleles. By querying 1375 genomes of the species-rich Malawi cichlid fish radiation, we discovered five large inversions segregating in the … Chromosomal inversions can contribute to adaptive speciation by linking coadapted alleles. By querying 1375 genomes of the species-rich Malawi cichlid fish radiation, we discovered five large inversions segregating in the benthic subradiation that each suppress recombination over more than half a chromosome. Two inversions were transferred from deepwater pelagic Diplotaxodon through admixture, whereas the others established early in the deep benthic clade. Introgression of haplotypes from lineages inside and outside the Malawi radiation coincided with bursts of species diversification. Inversions show evidence for transient sex linkage, and a notable excess of protein changing substitutions points toward selection on neurosensory, physiological, and reproductive genes. These results indicate that repeated interplay between depth adaptation and sex-specific selection on large inversions has been central to the evolution of this iconic system.

Ficha de Heliotrygon rosai

2025-06-12

Ricardo de Souza Rosa , Patrícia Charvet , Maria Lúcia Góes Araujo +5 more | Datasets - Sistema SALVE - ICMBio

Ficha de Heliotrygon gomesi

2025-06-12

Ricardo de Souza Rosa , Patrícia Charvet , Maria Lúcia Góes Araujo +5 more | Datasets - Sistema SALVE - ICMBio

Ficha de Aegla leptochela

2025-06-12

Sérgio L. S. Bueno , Alessandra Angélica de Pádua Bueno , Sandro Santos +3 more | Datasets - Sistema SALVE - ICMBio

Ocorrências de fosfato sedimentar em coberturas fanerozoicas na região de Arraias - TO, borda oeste da Bacia do São Francisco, Brasil

2025-06-12

Alex J. Choupina A. Silva , J. Franco , Juliana Okubo +1 more | Geologia USP Série Científica

The region of Arraias (TO) and Campos Belos (GO) is characterized by the presence of phosphorites and phosphate siltstones interdigitated with siltstones in the basal portion of the Sete Lagoas … The region of Arraias (TO) and Campos Belos (GO) is characterized by the presence of phosphorites and phosphate siltstones interdigitated with siltstones in the basal portion of the Sete Lagoas Formation, belonging to the Bambuí Group. In the upper Phanerozoic strata, occurs partially lithified polymictic conglomerates containing variable phosphate contents, likely due to the presence of reworked clasts of phosphatic rocks derived from underlying units. This paper describes the occurrence of isolated strata of Phanerozoic sediments containing polymictic conglomerate and unconsolidated covers, which are juxtaposed to the pelitic carbonate succession of the Sete Lagoas Formation on the western edge of the São Francisco Basin (SFB). The upper lithotypes suggest a braided fluvial depositional system, similar to the Cretaceous deposits of the Urucuia Group. Field observations, semi-detailed mapping, geological and the integration of data allowed the identification of phosphatic siltstone clasts within the polymictic conglomerate, with P2O5 concentrations ranging from <1.0% to 20%. The new geological data will support future exploratory studies on phosphate deposits in the area and highlight the occurrence of phanerozoic layers with erratic phosphate contents.

A Esquistossomose na Amazônia brasileira

2025-06-10

Virgílio Almeida , Danilo Duarte Paz , Luciana Corrêa | Revista Eletrônica Acervo Saúde

Objetivo: Avaliar as evidências disponíveis na literatura em relação ao cenário epidemiológico da Esquistossomose na Amazônia brasileira. Métodos: Revisão integrativa realizada nas bases de dados Web of Science, PubMed, BVS … Objetivo: Avaliar as evidências disponíveis na literatura em relação ao cenário epidemiológico da Esquistossomose na Amazônia brasileira. Métodos: Revisão integrativa realizada nas bases de dados Web of Science, PubMed, BVS e SciELO no período de 1980 a 2025, por meio dos descritores “Esquistossomose” e “amazônia”, analisando as publicações em português, inglês e espanhol. Resultados: Foram obtidas 15 referências, tendo os dados analisados e descritos em duas categorias, sendo elas a epidemiologia da Esquistossomose e a etiologia da Esquistossomose na Amazônia brasileira. Observou-se predominância do público do sexo masculino em idade adulta e residentes em áreas rurais. Além disso, há uma maior produção de artigos científicos no estado do Pará, onde houve o primeiro registro da doença dentro do contexto amazônico. Considerações finais: As evidências científicas acerca do cenário epidemiológico da Esquistossomose na Amazônia brasileira sugerem que a doença está associada à vulnerabilidade social da população afetada, principalmente devido a fatores como o saneamento básico precário nas áreas onde foram estudadas. Apesar da análise ampla de anos, observou-se baixa produção científica na região do estudo, o que evidencia a necessidade de pesquisas futuras voltadas a essa temática, principalmente por ser uma ferramenta para vigilância em saúde.

River Resilience: Assessment Using Empirical Fish Assemblage Traits

2025-06-10

Paulina Vega , Konrad Górski , Evelyn Habit | Water

The Andean river basins of central–southern Chile face multiple anthropogenic disturbances, including water extraction, hydropower, mining, and industrial discharges, which affect their ability to adapt to new disturbances. Disturbance intensity … The Andean river basins of central–southern Chile face multiple anthropogenic disturbances, including water extraction, hydropower, mining, and industrial discharges, which affect their ability to adapt to new disturbances. Disturbance intensity forms a gradient from high (Maipo, Rapel, Biobío, Maule) through medium (Mataquito, Itata) to low (Imperial, Toltén). This study evaluated resilience in these eight river basins based on fish assemblages, using taxonomic and functional trait indices within the framework of the three Rs of resilience: resources, recruitment, and refugia. Taxonomic indices captured changes in species richness, abundance, diversity, evenness, and beta diversity, while functional traits reflected the fish species characteristics promoting resilience. Statistical tests revealed significant differences in resilience indices among basins. Recruitment was the most impacted resilience mechanism, with beta diversity revealing effects from river fragmentation in the Maipo, Rapel, and Biobío basins. The resources mechanism was also affected, primarily by land-use changes and water pollution, leading to low species richness in the Maipo, Rapel, Mataquito, and Maule river basins. Interestingly, basins with medium disturbance levels showed high resilience, indicating adaptive responses to moderate impacts. This study emphasizes the importance of multiple indicators to assess ecosystem resilience and calls for integrated strategies to address the complex challenges impacting freshwater biodiversity.