Earth and Planetary Sciences › Oceanography

Marine Biology and Ecology Research

Works Count: 81071

Wikipedia

Description

This cluster of papers focuses on marine biodiversity, ecosystem functioning, and the ecological dynamics of benthic communities in various marine environments, including deep-sea habitats, estuaries, and hydrothermal vents. It explores topics such as taxonomic diversity, biogeography, the impact of climate change on marine ecosystems, and the relationships between species richness and ecosystem functioning.

Keywords

Marine Biodiversity; Ecosystem Functioning; Deep-Sea Ecology; Estuarine Quality; Benthic Communities; Taxonomic Diversity; Hydrothermal Vents; Biogeography; Sediment Biodiversity; Phylogenetic Relationships

The Effects of Macrobenthos on Chemical Properties of Marine Sediment and Overlying Water

1982-01-01

Robert C. Aller

Relation of Shell Form to Life Habits of the Bivalvia (Mollusca)

1970-01-01

Steven M. Stanley

Study of 95 Western Atlantic bivalve mollusk species representing 29 families has demonstrated that morphologic features of the bivalve shell other than hinge type and microstructure primarily reflect life habits … Study of 95 Western Atlantic bivalve mollusk species representing 29 families has demonstrated that morphologic features of the bivalve shell other than hinge type and microstructure primarily reflect life habits and habitat preferences. Many morphologic features represent potentially powerful tools for paleoecologic and evolutionary interpretation.

The Estuarine Quality Paradox, Environmental Homeostasis and the difficulty of detecting anthropogenic stress in naturally stressed areas

2007-04-07

Michael Elliott , Victor Quintino

Biogeography, biodiversity and fluid dependence of deep-sea cold-seep communities at active and passive margins

1998-01-01

Myriam Sibuet , Karine Olu

Deep-Sea Species Richness: Regional and Local Diversity Estimates from Quantitative Bottom Samples

1992-02-01

J. Frederick Grassle , Nancy J. Maciolek

The deep-sea communities of the continental slope and rise off the eastern coast of the United States have a remarkably high diversity-measured regionally or locally either as species richness or … The deep-sea communities of the continental slope and rise off the eastern coast of the United States have a remarkably high diversity-measured regionally or locally either as species richness or as the evenness of relative abundance among species. In a 1,500-2,500-m depth range off New Jersey and Delaware, 233 30 x 30-cm samples contained 798 species in 171 families and 14 phyla. Addition of stations from sites to the north and south approximately doubled the number of samples and doubled the number of species to 1,597. Species-area curves do not level off within stations or when stations are added together. Moreover, the proportion of species represented by single individuals is high at all scales of sampling, which indicates that much more sampling is needed to adequately represent the species richness either locally or regionally. Diversity changes very little through time at a single site or with distance along a 180-km transect at a depth of 2,100 m. Diversity is maintained by a combination of biogenic microhabitat heterogeneity in a system with few barriers to dispersal, disturbance created by feeding activities of larger animals, and food resources divided into patches of a few square meters to square centimeters initiated by specific temporally separated events.

Prokaryotic Cells in the Hydrothermal Vent Tube Worm Riftia pachyptila Jones: Possible Chemoautotrophic Symbionts

1981-07-17

Colleen M. Cavanaugh , Stephen L. Gardiner , Meredith L. Jones +2 more

The existence of a symbiotic association between vestimentiferan tube worms from deep-sea hydrothermal vents and chemoautotrophic sulfur-oxidizing prokaryotes, based on histological and enzymatic evidence, is suggested. The existence of a symbiotic association between vestimentiferan tube worms from deep-sea hydrothermal vents and chemoautotrophic sulfur-oxidizing prokaryotes, based on histological and enzymatic evidence, is suggested.

Biotic Interactions in Recent and Fossil Benthic Communities

1983-01-01

Michael J. S. Tevesz , Peter L. McCall

How Many Species Are There on Earth and in the Ocean?

2011-08-23

Camilo Mora , Derek P. Tittensor , Sina M. Adl +2 more

The diversity of life is one of the most striking aspects of our planet; hence knowing how many species inhabit Earth is among the most fundamental questions in science. Yet … The diversity of life is one of the most striking aspects of our planet; hence knowing how many species inhabit Earth is among the most fundamental questions in science. Yet the answer to this question remains enigmatic, as efforts to sample the world's biodiversity to date have been limited and thus have precluded direct quantification of global species richness, and because indirect estimates rely on assumptions that have proven highly controversial. Here we show that the higher taxonomic classification of species (i.e., the assignment of species to phylum, class, order, family, and genus) follows a consistent and predictable pattern from which the total number of species in a taxonomic group can be estimated. This approach was validated against well-known taxa, and when applied to all domains of life, it predicts ∼8.7 million (±1.3 million SE) eukaryotic species globally, of which ∼2.2 million (±0.18 million SE) are marine. In spite of 250 years of taxonomic classification and over 1.2 million species already catalogued in a central database, our results suggest that some 86% of existing species on Earth and 91% of species in the ocean still await description. Renewed interest in further exploration and taxonomy is required if this significant gap in our knowledge of life on Earth is to be closed.

View PDF Chat

A Practical Strategy for Analysing Multispecies Distribution Patterns

1982-01-01

JG Field , KR Clarke , R.M. Warwick

A strategy is presented for analysing marine biological survey data and relating the biotic patterns to environmental data.To avoid circular argument, biotic and environmental data are kept separate.The strategy is … A strategy is presented for analysing marine biological survey data and relating the biotic patterns to environmental data.To avoid circular argument, biotic and environmental data are kept separate.The strategy is illustrated by a worked example using data on the distribution of 182 nematode species in 107 samples in the River Exe estuary.Nineteen stations are grouped Into 4 main clusters using complementary classification and multi-dimensional scaling (MDS) ordination techniques.These are both based on root-root transformed abundance data with the Bray-Curtis measure of similarity.Indicator species characterising each group are extracted using information statistics.Inverse analyses give clusters of CO-occurnng species which are strongly related to the station groups.Relationships of station groups to environmental variables are revealed by superimposing data for one variable a t a time on the MDS plot, showing that some station groups differ in sediment granulometry and others in salinity, for example.Some of the other factors plotted show no difference between station groups.Similarly, physiognomic charactcrlstics of the species are superimposed on the MDS plots of the inverse analysis of species groups, revealing differences in setal length and trophic status between the species groups.Finally, the 4 major station groups and species groups are related to one another in terms of morphological adaptation to the habitat.

View PDF Chat

A further biodiversity index applicable to species lists: variation in taxonomic distinctness

2001-01-01

KR Clarke , RM Warwick

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 216:265-278 (2001) - doi:10.3354/meps216265 … MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 216:265-278 (2001) - doi:10.3354/meps216265 A further biodiversity index applicable to species lists: variation in taxonomic distinctness K. R. Clarke*, R. M. Warwick Plymouth Marine Laboratory, Prospect Place, West Hoe, Plymouth PL1 3DH, United Kingdom *E-mail: [email protected] ABSTRACT: A further biodiversity index is proposed, based on taxonomic (or phylogenetic) relatedness of species, namely the 'variation in taxonomic distinctness¹ (VarTD, Λ+) between every pair of species recorded in a study. It complements the previously defined 'average taxonomic distinctness' (AvTD, Δ+), which is the mean path length through the taxonomic tree connecting every pair of species in the list. VarTD is simply the variance of these pairwise path lengths and reflects the unevenness of the taxonomic tree. For example, a species list in which there are several different orders represented only by a single species, but also some genera which are very species-rich, would give a high Λ+ by comparison with a list (of equivalent Δ+) in which all species tended to be from different families but the same order. VarTD is shown to have the same desirable sampling properties as AvTD, primarily a lack of dependence of its mean value on the sample size (except for unrealistically small samples). Such unbiasedness is of crucial importance in making valid biodiversity comparisons between studies at different locations or times, with differing or uncontrolled degrees of sampling effort. This feature is emphatically not shared by indices related to species richness and also not by properties of the phylogeny adapted from proposals in other, conservation contexts, such as 'average phylogenetic diversity' (AvPD, Φ+). As with AvTD, the VarTD statistic for any local study can be tested for 'departure from expectation', based on a master taxonomy for that region, by constructing a simulation distribution from random subsets of the master list. The idea can be extended to summarising the joint distribution of AvTD and VarTD, so that values from real data sets are compared with a fitted simulation 'envelope' in a 2 d (Δ+, Λ+) plot. The methodology is applied to 14 species lists of free-living marine nematodes, and related to a master list for UK waters. The combination of AvTD and VarTD picks out, in different ways, some degraded locations (low Δ+, low to normal Λ+) and the pristine island fauna of the Scillies (normal Δ+, high Λ+). The 2 indices are also demonstrated to be measuring effectively independent features of the taxonomic tree, at least for this faunal group (although it is shown theoretically that this will not always be the case). The combination of Δ+ and Λ+ is therefore seen to provide a statistically robust summary of taxonomic (or phylogenetic) relatedness patterns within an assemblage, which has the potential to be applied to a wide range of historical data in the form of simple species lists. KEY WORDS: Biodiversity · Taxonomic distinctness · Phylogenetic diversity · Sampling properties · Simulation · British marine nematodes Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 216. Online publication date: July 06, 2001 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2001 Inter-Research.

View PDF Chat

Reorganization of North Atlantic Marine Copepod Biodiversity and Climate

2002-05-31

Grégory Beaugrand , Philip C. Reid , Frédéric Ibañez +2 more

We provide evidence of large-scale changes in the biogeography of calanoid copepod crustaceans in the eastern North Atlantic Ocean and European shelf seas. We demonstrate that strong biogeographical shifts in … We provide evidence of large-scale changes in the biogeography of calanoid copepod crustaceans in the eastern North Atlantic Ocean and European shelf seas. We demonstrate that strong biogeographical shifts in all copepod assemblages have occurred with a northward extension of more than 10° latitude of warm-water species associated with a decrease in the number of colder-water species. These biogeographical shifts are in agreement with recent changes in the spatial distribution and phenology detected for many taxonomic groups in terrestrial European ecosystems and are related to both the increasing trend in Northern Hemisphere temperature and the North Atlantic Oscillation.

Extinction and Ecosystem Function in the Marine Benthos

2004-11-11

Martin Solan , Bradley J. Cardinale , Amy L. Downing +3 more

Rapid changes in biodiversity are occurring globally, yet the ecological impacts of diversity loss are poorly understood. Here we use data from marine invertebrate communities to parameterize models that predict … Rapid changes in biodiversity are occurring globally, yet the ecological impacts of diversity loss are poorly understood. Here we use data from marine invertebrate communities to parameterize models that predict how extinctions will affect sediment bioturbation, a process vital to the persistence of aquatic communities. We show that species extinction is generally expected to reduce bioturbation, but the magnitude of reduction depends on how the functional traits of individual species covary with their risk of extinction. As a result, the particular cause of extinction and the order in which species are lost ultimately govern the ecosystem-level consequences of biodiversity loss.

A method of linking multivariate community structure to environmental variables

1993-01-01

KR Clarke , Martyn Ainsworth

The method of choice for multivariate representation of community structure is often non-metric multi-dimensional scaling (MDS).This has great flexibility in accomn~odating biologically relevant (i.e.non correlation-based) definitions of similarity In species … The method of choice for multivariate representation of community structure is often non-metric multi-dimensional scaling (MDS).This has great flexibility in accomn~odating biologically relevant (i.e.non correlation-based) definitions of similarity In species composition of 2 samples, and in preserving the rank-order relations amongst those similarities in the placing of samples in an ordination.Correlation-based techniques (such as Canonical Correlation) are then inappropriate in linking the observed biotic structure to measured environmental variables; a more natural approach is simply to compare separate sample ordinations from biotic and abiotic variables and choose that subset of environmental variables which provides a good match between the 2 configurations.In fact, the fundamental constructs here are not the ordination plots but the (rank) similarity matrices which underlie them: a suitable measure of agreement between 2 such matrices is therefore proposed and used to define an optimal subset of environmental variables w h ~c h 'best explains' the biotic structure.This simple technique is illustrated wlth 3 data sets, from studles of macrobenthic, meiobenthic and diatom communities in estuarine and coastal waters.

Seasonal sedimentation of phytoplankton to the deep-sea benthos

1983-04-01

D. S. M. Billett , Richard S. Lampitt , A.L. Rice +1 more

New 'biodiversity' measures reveal a decrease in taxonomic distinctness with increasing stress

1995-01-01

RM Warwick , KR Clarke

View PDF Chat

Symbiotic diversity in marine animals: the art of harnessing chemosynthesis

2008-09-16

Nicole Dubilier , Claudia Bergin , Christian Lott

Diversity of Planktonic Foraminifera in Deep-Sea Sediments

1970-06-12

Wolfgang Berger , Frances L. Parker

The diversity of a planktonic foraminiferal assemblage on the ocean floor depends on the state of preservation of that assemblage. As dissolution progresses, species diversity (number of species in the … The diversity of a planktonic foraminiferal assemblage on the ocean floor depends on the state of preservation of that assemblage. As dissolution progresses, species diversity (number of species in the assemblage) decreases, but compound diversity (based on relative species abundance) first increases and then decreases; species dominance first decreases and then increases. The reason for these changes is that the species most susceptible to solution deliver moresediment to the ocean floor than do species with solution-resistant shells, possibly because the more soluble tests are produced in surface waters, where growth and production are greatest.

Benthic suspension feeders: their paramount role in littoral marine food webs

1998-08-01

Josep María Gili , Rafel Coma

Marine Benthic Diversity: A Comparative Study

1968-05-01

Howard L. Sanders

In this paper a methodology is presented for measuring diversity based on rarefaction of actual samples. By the use of this technique, a within-habitat analysis was made of the bivalve … In this paper a methodology is presented for measuring diversity based on rarefaction of actual samples. By the use of this technique, a within-habitat analysis was made of the bivalve and polychaete components of soft-bottom marine faunas which differed in latitude, depth, temperature, and salinity. The resulting diversity values were highly correlated with the physical stability and past history of these environments. A stability-time hypothesis was invoked to fit these findings, and, with this hypothesis, predictions were made about the diversities present in certain other environments as yet unstudied. The two types of diversity, based on numerical percentage composition and on number of species, were compared and shown to be poorly correlated with each other. Our data indicated that species number is the more valid diversity measurement. The rarefaction methodology was compared with a number of diversity indexes using identical data. Many of these indexes were markedly influenced by sample size. Good agreement was found between the rarefaction methodology and the Shannon-Wiener information function.

A new method for detecting pollution effects on marine macrobenthic communities

1986-09-01

R.M. Warwick

Mineralization of organic matter in the sea bed—the role of sulphate reduction

1982-04-01

Bo Barker Jørgensen

Expanding Oxygen-Minimum Zones in the Tropical Oceans

2008-05-02

Lothar Stramma , Gregory C. Johnson , Janet Sprintall +1 more

Oxygen-poor waters occupy large volumes of the intermediate-depth eastern tropical oceans. Oxygen-poor conditions have far-reaching impacts on ecosystems because important mobile macroorganisms avoid or cannot survive in hypoxic zones. Climate … Oxygen-poor waters occupy large volumes of the intermediate-depth eastern tropical oceans. Oxygen-poor conditions have far-reaching impacts on ecosystems because important mobile macroorganisms avoid or cannot survive in hypoxic zones. Climate models predict declines in oceanic dissolved oxygen produced by global warming. We constructed 50-year time series of dissolved-oxygen concentration for select tropical oceanic regions by augmenting a historical database with recent measurements. These time series reveal vertical expansion of the intermediate-depth low-oxygen zones in the eastern tropical Atlantic and the equatorial Pacific during the past 50 years. The oxygen decrease in the 300- to 700-m layer is 0.09 to 0.34 micromoles per kilogram per year. Reduced oxygen levels may have dramatic consequences for ecosystems and coastal economies.

View PDF Chat

Biological Accommodation in the Benthic Community at McMurdo Sound, Antarctica

1974-01-01

Paul K. Dayton , Gordon A. Robilliard , Robert T. Paine +1 more

Studies of the benthos between 30 and 60 m at Cape Armitage, McMurdo Sound. Antarctica, reveal an epifaunal community in which sponges and their asteroid and nudibranch predators predominate. Field … Studies of the benthos between 30 and 60 m at Cape Armitage, McMurdo Sound. Antarctica, reveal an epifaunal community in which sponges and their asteroid and nudibranch predators predominate. Field experiments demonstrated that, with the exception of Mycale accrata, the growth rates of the sponges are too slow to measure in one year. Mycale, however, was observed to increase its mass as much as 67%. Because of its more rapid growth rate, Mycale appears to be the potential dominant in competition for substratum space, the resource potentially limiting to the sessile species. This conclusion is supported by observations of Mycale growing over and, in some cases, apparently having smothered many other sessile species representing at least three phyla. The densities and size frequency distributions of all the predators were measured; numerous feeding observations allowed an accurate appraisal of dietary compositions. Because of the predators' very slow consumption rates, however, direct measures of ingestion and its impact on prey populations were not possible. Estimates of the ingestion rates were derived from measurements of predator respiration rates, growth rates, and gonad growth. Data from the field surveys and the energetics studies suggest that Mycale is prevented from dominating the space resource by the predation of two asteroids. Perknaster fuscus antarcticus and Acodontaster conspicuus. Adult Perknaster specialize on Mycale, and the sponge provides a small proportion of the diet of A. conspicuus. Acodontaster conspicuus and the dorid nudibranch Austrodoris memurdensis are the most important predators on three species of rossellid sponges (Rossella racovitzae, R. nuda, and Scolymastra joubini). Despite this relatively heavy consumption and despite the fact that none of these sponges has a refuge in growth from potential mortality from A. conspicuus, very large standing crops of the rossellid sponges have accumulated. This accumulation appears to result from predation on larval and young A. conspicuus and Austrodoris by Odontaster validus, which is primarily a detrital feeder and apparently acts as a filter against the settlement and survival of the A. conspicuus and Austrodoris larvae. In addition, predation upon adult A. conspicuus by O. validus and the actinian urticinopsis antarcticus annually kills approximately 3.5% of the A. conspicuus population. This mortality exceeds the apparent rate at which A. conspicuus escape the larval filter.

DNA Barcoding: Error Rates Based on Comprehensive Sampling

2005-11-18

Chris Meyer , Gustav Paulay

DNA barcoding has attracted attention with promises to aid in species identification and discovery; however, few well-sampled datasets are available to test its performance. We provide the first examination of … DNA barcoding has attracted attention with promises to aid in species identification and discovery; however, few well-sampled datasets are available to test its performance. We provide the first examination of barcoding performance in a comprehensively sampled, diverse group (cypraeid marine gastropods, or cowries). We utilize previous methods for testing performance and employ a novel phylogenetic approach to calculate intraspecific variation and interspecific divergence. Error rates are estimated for (1) identifying samples against a well-characterized phylogeny, and (2) assisting in species discovery for partially known groups. We find that the lowest overall error for species identification is 4%. In contrast, barcoding performs poorly in incompletely sampled groups. Here, species delineation relies on the use of thresholds, set to differentiate between intraspecific variation and interspecific divergence. Whereas proponents envision a "barcoding gap" between the two, we find substantial overlap, leading to minimal error rates of approximately 17% in cowries. Moreover, error rates double if only traditionally recognized species are analyzed. Thus, DNA barcoding holds promise for identification in taxonomically well-understood and thoroughly sampled clades. However, the use of thresholds does not bode well for delineating closely related species in taxonomically understudied groups. The promise of barcoding will be realized only if based on solid taxonomic foundations.

View PDF Chat

Non‐parametric multivariate analyses of changes in community structure

1993-03-01

K.R. Clarke

Abstract In the early 1980s, a strategy for graphical representation of multivariate (multi‐species) abundance data was introduced into marine ecology by, among others, Field, et al. (1982). A decade on, … Abstract In the early 1980s, a strategy for graphical representation of multivariate (multi‐species) abundance data was introduced into marine ecology by, among others, Field, et al. (1982). A decade on, it is instructive to: (i) identify which elements of this often‐quoted strategy have proved most useful in practical assessment of community change resulting from pollution impact; and (ii) ask to what extent evolution of techniques in the intervening years has added self‐consistency and comprehensiveness to the approach. The pivotal concept has proved to be that of a biologically‐relevant definition of similarity of two samples, and its utilization mainly in simple rank form, for example ‘sample A is more similar to sample B than it is to sample C’. Statistical assumptions about the data are thus minimized and the resulting non‐parametric techniques will be of very general applicability. From such a starting point, a unified framework needs to encompass: (i) the display of community patterns through clustering and ordination of samples; (ii) identification of species principally responsible for determining sample groupings; (iii) statistical tests for differences in space and time (multivariate analogues of analysis of variance, based on rank similarities); and (iv) the linking of community differences to patterns in the physical and chemical environment (the latter also dictated by rank similarities between samples). Techniques are described that bring such a framework into place, and areas in which problems remain are identified. Accumulated practical experience with these methods is discussed, in particular applications to marine benthos, and it is concluded that they have much to offer practitioners of environmental impact studies on communities.

Effects of nutrient enrichment in the nation's estuaries: A decade of change

2008-09-20

Suzanne B. Bricker , Ben Longstaff , William C. Dennison +4 more

View PDF Chat

Cladistics and polychaetes

1997-04-01

Greg W. Rouse , Kristian Fauchald

A series of cladistic analyses assesses the status and membership of the taxon Polychaeta. The available literature, and a review by Fauchald & Rouse (1997), on the 80 accepted families … A series of cladistic analyses assesses the status and membership of the taxon Polychaeta. The available literature, and a review by Fauchald & Rouse (1997), on the 80 accepted families of the Polychaeta are used to develop characters and data matrices. As well as the polychaete families, non‐polychaete taxa, such as the Echiura, Euarthropoda, Onychophora, Pogonophora (as Frenulata and Vestimentifera), Clitellata, Aeolosomatidae and Potamodrilidae, are included in the analyses. All trees are rooted using the Sipuncula as outgroup. Characters are based on features (where present) such as the prostomium, peristomium, antennae, palps, nuchal organs, parapodia, stomodaeum, segmental organ structure and distribution, circulation and chaetae. A number of analyses are performed, involving different ways of coding and weighting the characters, as well as the number of taxa included. Transformation series are provided for several of these analyses. One of the analyses is chosen to provide a new classification. The Annelida is found to be monophyletic, though weakly supported, and comprises the Clitellata and Polychaeta. The Polychaeta is monophyletic only if taxa such as the Pogonophora, Aeolosomatidae and Potamodrilidae are included and is also weakly supported. The Pogonophora is reduced to the rank of family within the Polychaeta and reverts to the name Siboglinidae Caullery, 1914. The new classification does not use Linnaean categories, and the Polychaeta comprises two clades, the Scolecida and Palpata. The Palpata has the clades Aciculata and Canalipalpata. The Aciculata contains the Phyllodocida and Eunicida. The Canalipalpata has three clades; the Sabellida (including the Siboglinidae) Spionida and Terebellida. The position of a number of families requires further investigation.

Effects of natural and human-induced hypoxia on coastal benthos

2009-10-08

Lisa A. Levin , Werner Ekau , Andrew J. Gooday +6 more

Abstract. Coastal hypoxia (defined here as <1.42 ml L−1; 62.5 μM; 2 mg L−1, approx. 30% oxygen saturation) develops seasonally in many estuaries, fjords, and along open coasts as a … Abstract. Coastal hypoxia (defined here as <1.42 ml L−1; 62.5 μM; 2 mg L−1, approx. 30% oxygen saturation) develops seasonally in many estuaries, fjords, and along open coasts as a result of natural upwelling or from anthropogenic eutrophication induced by riverine nutrient inputs. Permanent hypoxia occurs naturally in some isolated seas and marine basins as well as in open slope oxygen minimum zones. Responses of benthos to hypoxia depend on the duration, predictability, and intensity of oxygen depletion and on whether H2S is formed. Under suboxic conditions, large mats of filamentous sulfide oxidizing bacteria cover the seabed and consume sulfide. They are hypothesized to provide a detoxified microhabitat for eukaryotic benthic communities. Calcareous foraminiferans and nematodes are particularly tolerant of low oxygen concentrations and may attain high densities and dominance, often in association with microbial mats. When oxygen is sufficient to support metazoans, small, soft-bodied invertebrates (typically annelids), often with short generation times and elaborate branchial structures, predominate. Large taxa are more sensitive than small taxa to hypoxia. Crustaceans and echinoderms are typically more sensitive to hypoxia, with lower oxygen thresholds, than annelids, sipunculans, molluscs and cnidarians. Mobile fish and shellfish will migrate away from low-oxygen areas. Within a species, early life stages may be more subject to oxygen stress than older life stages. Hypoxia alters both the structure and function of benthic communities, but effects may differ with regional hypoxia history. Human-caused hypoxia is generally linked to eutrophication, and occurs adjacent to watersheds with large populations or agricultural activities. Many occurrences are seasonal, within estuaries, fjords or enclosed seas of the North Atlantic and the NW Pacific Oceans. Benthic faunal responses, elicited at oxygen levels below 2 ml L−1, typically involve avoidance or mortality of large species and elevated abundances of enrichment opportunists, sometimes prior to population crashes. Areas of low oxygen persist seasonally or continuously beneath upwelling regions, associated with the upper parts of oxygen minimum zones (SE Pacific, W Africa, N Indian Ocean). These have a distribution largely distinct from eutrophic areas and support a resident fauna that is adapted to survive and reproduce at oxygen concentrations <0.5 ml L−1. Under both natural and eutrophication-caused hypoxia there is loss of diversity, through attrition of intolerant species and elevated dominance, as well as reductions in body size. These shifts in species composition and diversity yield altered trophic structure, energy flow pathways, and corresponding ecosystem services such as production, organic matter cycling and organic C burial. Increasingly the influences of nature and humans interact to generate or exacerbate hypoxia. A warmer ocean is more stratified, holds less oxygen, and may experience greater advection of oxygen-poor source waters, making new regions subject to hypoxia. Future understanding of benthic responses to hypoxia must be established in the context of global climate change and other human influences such as overfishing, pollution, disease, habitat loss, and species invasions.

View PDF Chat

A Marine Biotic Index to Establish the Ecological Quality of Soft-Bottom Benthos Within European Estuarine and Coastal Environments

2000-12-01

Ángel Borja , Javier Franco , VR Burns Perez

Estimating the grazing impact of marine micro-zooplankton

1982-05-01

Michael R. Landry , R. P. Hassett

The ecology of deep-sea hydrothermal vents

2000-10-01

Cindy Lee Van Dover

Teeming with weird and wonderful life--giant clams and mussels, tubeworms, eyeless shrimp, and bacteria that survive on sulfur--deep-sea hot-water springs are found along rifts where sea-floor spreading occurs. The theory … Teeming with weird and wonderful life--giant clams and mussels, tubeworms, eyeless shrimp, and bacteria that survive on sulfur--deep-sea hot-water springs are found along rifts where sea-floor spreading occurs. The theory of plate tectonics predicted the existence of these hydrothermal vents, but they were discovered only in 1977. Since then the sites have attracted teams of scientists seeking to understand how life can thrive in what would seem to be intolerable or extreme conditions of temperature and fluid chemistry. Some suspect that these vents even hold the key to understanding the very origins of life. Here a leading expert provides the first authoritative and comprehensive account of this research in a book intended for students, professionals, and general readers. Cindy Lee Van Dover, an ecologist, brings nearly two decades of experience and a lively writing style to the text, which is further enhanced by two hundred illustrations, including photographs of vent communities taken in situ. The book begins by explaining what is known about hydrothermal systems in terms of their deep-sea environment and their geological and chemical makeup. The coverage of microbial ecology includes a chapter on symbiosis. Symbiotic relationships are further developed in a section on physiological ecology, which includes discussions of adaptations to sulfide, thermal tolerances, and sensory adaptations. Separate chapters are devoted to trophic relationships and reproductive ecology. A chapter on community dynamics reveals what has been learned about the ways in which vent communities become established and why they persist, while a chapter on evolution and biogeography examines patterns of species diversity and evolutionary relationships within chemosynthetic ecosystems. Cognate communities such as seeps and whale skeletons come under scrutiny for their ability to support microbial and invertebrate communities that are ecologically and evolutionarily related to hydrothermal faunas. The book concludes by exploring the possibility that life originated at hydrothermal vents, a hypothesis that has had tremendous impact on our ideas about the potential for life on other planets or planetary bodies in our solar system.

Multivariate dispersion as a measure of beta diversity

2006-04-25

Marti J. Anderson , Kari E. Ellingsen , Brian H. McArdle

Abstract Beta diversity can be defined as the variability in species composition among sampling units for a given area. We propose that it can be measured as the average dissimilarity … Abstract Beta diversity can be defined as the variability in species composition among sampling units for a given area. We propose that it can be measured as the average dissimilarity from individual observation units to their group centroid in multivariate space, using an appropriate dissimilarity measure. Differences in beta diversity among different areas or groups of samples can be tested using this approach. The choice of transformation and dissimilarity measure has important consequences for interpreting results. For kelp holdfast assemblages from New Zealand, variation in species composition was greater in smaller holdfasts, while variation in relative abundances was greater in larger holdasts. Variation in community structure of Norwegian continental shelf macrobenthic fauna increased with increases in environmental heterogeneity, regardless of the measure used. We propose a new dissimilarity measure which allows the relative weight placed on changes in composition vs. abundance to be specified explicitly.

DISTANCE-BASED REDUNDANCY ANALYSIS: TESTING MULTISPECIES RESPONSES IN MULTIFACTORIAL ECOLOGICAL EXPERIMENTS

1999-02-01

Pierre Legendre , Marti J. Anderson

We present a new multivariate technique for testing the significance of individual terms in a multifactorial analysis-of-variance model for multispecies response variables. The technique will allow researchers to base analyses … We present a new multivariate technique for testing the significance of individual terms in a multifactorial analysis-of-variance model for multispecies response variables. The technique will allow researchers to base analyses on measures of association (distance measures) that are ecologically relevant. In addition, unlike other distance-based hypothesis-testing techniques, this method allows tests of significance of interaction terms in a linear model. The technique uses the existing method of redundancy analysis (RDA) but allows the analysis to be based on Bray-Curtis or other ecologically meaningful measures through the use of principal coordinate analysis (PCoA). Steps in the procedure include: (1) calculating a matrix of distances among replicates using a distance measure of choice (e.g., Bray-Curtis); (2) determining the principal coordinates (including a correction for negative eigenvalues, if necessary), which preserve these distances; (3) creating a matrix of dummy variables corresponding to the design of the experiment (i.e., individual terms in a linear model); (4) analyzing the relationship between the principal coordinates (species data) and the dummy variables (model) using RDA; and (5) implementing a test by permutation for particular statistics corresponding to the particular terms in the model. This method has certain advantages not shared by other multivariate testing procedures. We demonstrate the use of this technique with experimental ecological data from intertidal assemblages and show how the presence of significant multivariate interactions can be interpreted. It is our view that distance-based RDA will be extremely useful to ecologists measuring multispecies responses to structured multifactorial experimental designs.

Global distribution of naturally occurring marine hypoxia on continental margins

2004-08-05

J. Helly , Lisa A. Levin

Out of the Tropics: Evolutionary Dynamics of the Latitudinal Diversity Gradient

2006-10-06

David Jablonski , Kaustuv Roy , James W. Valentine

The evolutionary dynamics underlying the latitudinal gradient in biodiversity have been controversial for over a century. Using a spatially explicit approach that incorporates not only origination and extinction but immigration, … The evolutionary dynamics underlying the latitudinal gradient in biodiversity have been controversial for over a century. Using a spatially explicit approach that incorporates not only origination and extinction but immigration, a global analysis of genera and subgenera of marine bivalves over the past 11 million years supports an “out of the tropics” model, in which taxa preferentially originate in the tropics and expand toward the poles without losing their tropical presence. The tropics are thus both a cradle and a museum of biodversity, contrary to the conceptual dichotomy dominant since 1974; a tropical diversity crisis would thus have profound evolutionary effects at all latitudes.

The maturity index: an ecological measure of environmental disturbance based on nematode species composition

1990-05-01

Tom Bongers

Disturbance to Marine Benthic Habitats by Trawling and Dredging: Implications for Marine Biodiversity

2002-11-01

Simon F. Thrush , Paul K. Dayton

▪ Abstract The direct effects of marine habitat disturbance by commercial fishing have been well documented. However, the potential ramifications to the ecological function of seafloor communities and ecosystems have … ▪ Abstract The direct effects of marine habitat disturbance by commercial fishing have been well documented. However, the potential ramifications to the ecological function of seafloor communities and ecosystems have yet to be considered. Soft-sediment organisms create much of their habitat's structure and also have crucial roles in many population, community, and ecosystem processes. Many of these roles are filled by species that are sensitive to habitat disturbance. Functional extinction refers to the situation in which species become so rare that they do not fulfill the ecosystem roles that have evolved in the system. This loss to the ecosystem occurs when there are restrictions in the size, density, and distribution of organisms that threaten the biodiversity, resilience, or provision of ecosystem services. Once the functionally important components of an ecosystem are missing, it is extremely difficult to identify and understand ecological thresholds. The extent and intensity of human disturbance to oceanic ecosystems is a significant threat to both structural and functional biodiversity and in many cases this has virtually eliminated natural systems that might serve as baselines to evaluate these impacts.

Local Adaptation in Marine Invertebrates

2010-12-15

Eric Sanford , Morgan W. Kelly

Local adaptation in the sea was regarded historically as a rare phenomenon that was limited to a handful of species with exceptionally low dispersal potential. However, a growing body of … Local adaptation in the sea was regarded historically as a rare phenomenon that was limited to a handful of species with exceptionally low dispersal potential. However, a growing body of experimental studies indicates that adaptive differentiation occurs in numerous marine invertebrates in response to selection imposed by strong gradients (and more complex mosaics) of abiotic and biotic conditions. Moreover, a surprisingly high proportion of the marine invertebrates known or suspected of exhibiting local adaptation are species with planktonic dispersal. Adaptive divergence among populations can occur over a range of spatial scales, including those that are fine-grained (i.e., meters to kilometers), reflecting a balance between scales of gene flow and selection. Addressing the causes and consequences of adaptive genetic differentiation among invertebrate populations promises to advance community ecology, climate change research, and the effective management of marine ecosystems.

Environmental Influences on Regional Deep-Sea Species Diversity

2001-11-01

Lisa A. Levin , Ron J. Etter , Michael A. Rex +6 more

▪ Abstract Most of our knowledge of biodiversity and its causes in the deep-sea benthos derives from regional-scale sampling studies of the macrofauna. Improved sampling methods and the expansion of … ▪ Abstract Most of our knowledge of biodiversity and its causes in the deep-sea benthos derives from regional-scale sampling studies of the macrofauna. Improved sampling methods and the expansion of investigations into a wide variety of habitats have revolutionized our understanding of the deep sea. Local species diversity shows clear geographic variation on spatial scales of 100–1000 km. Recent sampling programs have revealed unexpected complexity in community structure at the landscape level that is associated with large-scale oceanographic processes and their environmental consequences. We review the relationships between variation in local species diversity and the regional-scale phenomena of boundary constraints, gradients of productivity, sediment heterogeneity, oxygen availability, hydrodynamic regimes, and catastrophic physical disturbance. We present a conceptual model of how these interdependent environmental factors shape regional-scale variation in local diversity. Local communities in the deep sea may be composed of species that exist as metapopulations whose regional distribution depends on a balance among global-scale, landscape-scale, and small-scale dynamics. Environmental gradients may form geographic patterns of diversity by influencing local processes such as predation, resource partitioning, competitive exclusion, and facilitation that determine species coexistence. The measurement of deep-sea species diversity remains a vital issue in comparing geographic patterns and evaluating their potential causes. Recent assessments of diversity using species accumulation curves with randomly pooled samples confirm the often-disputed claim that the deep sea supports higher diversity than the continental shelf. However, more intensive quantitative sampling is required to fully characterize the diversity of deep-sea sediments, the most extensive habitat on Earth. Once considered to be constant, spatially uniform, and isolated, deep-sea sediments are now recognized as a dynamic, richly textured environment that is inextricably linked to the global biosphere. Regional studies of the last two decades provide the empirical background necessary to formulate and test specific hypotheses of causality by controlled sampling designs and experimental approaches.

Barium in Deep‐Sea Sediment: A Geochemical Proxy for Paleoproductivity

1992-04-01

Jack Dymond , Erwin Suess , Mitchell W Lyle

We used sediment traps to define the particulate fluxes of barium and organic carbon and investigate the use of barium as a proxy for ocean fertility. Strong correlations between C … We used sediment traps to define the particulate fluxes of barium and organic carbon and investigate the use of barium as a proxy for ocean fertility. Strong correlations between C org and Ba fluxes indicate a link between upper ocean biological processes and barium flux to the seafloor. The ratio of organic carbon to barium decreases systematically with water depth. Data from 10 sites indicate that organic debris settling from the 200‐m depth has a C org /Ba ratio of approximately 200. The systematic decrease in this ratio with increasing water depth results from the simultaneous decay of organic matter and uptake of Ba in settling particles. This behavior provides additional evidence that the formation of barite in oceanic particles is a consequence of decomposition/uptake in microenvironments rather than the secretion of barite by specific organisms. The decrease of the Corg/Ba ratio with depth is greatest in the North Pacific followed by the equatorial Pacific and is lowest in the western Atlantic. Since this spatial pattern is consistent with the variations in the deep‐ocean barium contents which increase along the path of bottom water flow from the Atlantic to the North Pacific, it suggests that the particulate barium uptake and flux is enhanced by higher barium contents in the intermediate and deep waters of the ocean. Consequently, we have combined our particle flux data with existing water column Ba data to define an algorithm relating new productivity, dissolved barium contents, water depth, and particulate barium flux. This relationship provides a basis of applying barium flux measurements in sediments to estimating new production. In order to use barium as an indicator of productivity, it will be necessary to evaluate inputs from hydrothermal and aluminosilicate sources and xenophyophors. The application of a sequential leach procedure to the trap material indicates that 50‐70% of the Ba in settling particles is in the form of barite and the remaining is adsorbed or bound to carbonates. Normative analysis demonstrates that in nearshore areas the contribution of barium from aluminosilicate sources can dominate that from biogenic inputs. It appears that normative estimates of biogenic barium contents can be made with accuracy if less than 50% of the Ba is associated with aluminosilicates; i.e., is of terrigenous origin. Since diagenetic mobilization of Ba can occur in reduced and suboxic sediments, highly productive nearshore areas also are likely to be inappropriate sites to use Ba measurements as productivity indicators. Comparisons between the rain rates of particulate Ba to the seafloor and the burial rate indicate that approximately 30% of the Ba rain is preserved. Although the preservation factor does not appear to be constant, it may be possible to predict the extent of preservation from an empirical relationship with the mass accumulation rate. These observations indicate that measurement of Ba burial fluxes in sediments can provide quantitative information on the paleoproductivity of the oceans. Joining the relationship between barium rain and burial with the barium and organic carbon algorithm, we make estimates of the new production in the northern California Current during the last 18,000 years. This calculation suggests that new production was at least a factor of 2 lower at this site during the last glacial maximum.

View PDF Chat

OXYGEN MINIMUM ZONE BENTHOS: ADAPTATION AND COMMUNITY RESPONSE TO HYPOXIA

2003-07-31

Lisa A. Levin

Mid-water oxygen minima (0.5ml l1 dissolved O2) intercept the continental margins along much of the eastern Pacific Ocean, off west Africa and in the Arabian Sea and Bay of Bengal, … Mid-water oxygen minima (0.5ml l1 dissolved O2) intercept the continental margins along much of the eastern Pacific Ocean, off west Africa and in the Arabian Sea and Bay of Bengal, creating extensive stretches of sea floor exposed to permanent, severe oxygen depletion. These seafloor oxygen minimum zones (OMZs) typically occur at bathyal depths between 200m and 1000m, and are major sites of carbon burial along the continental margins. Despite extreme oxygen depletion, protozoan and metazoan assemblages thrive in these environments. Metazoan adaptations include small, thin bodies, enhanced respiratory surface area, blood pigments such as haemoglobin, biogenic structure formation for stability in soupy sediments, an increased number of pyruvate oxidoreductases, and the presence of sulphide-oxidising symbionts. The organic-rich sediments of these regions often support mats of large sulphideoxidising bacteria (Thioploca, Beggiatoa, Thiomargarita), and high-density, low-diversity metazoan assemblages. Densities of protistan and metazoan meiofauna are typically elevated in OMZs, probably due to high tolerance of hypoxia, an abundant food supply, and release from predation. Macrofauna and megafauna often exhibit dense aggregations at OMZ edges, but depressed densities and low diversity in the OMZ core, where oxygen concentration is lowest. Taxa most tolerant of severe oxygen depletion (0.2ml l1) in seafloor OMZs include calcareous foraminiferans, nematodes, and annelids. Agglutinated protozoans, harpacticoid copepods, and calcified invertebrates are typically less tolerant. High dominance and relatively low species richness are exhibited by foraminiferans, metazoan meiofauna, and macrofauna within OMZs. At dissolved oxygen concentrations below 0.15ml l1, bioturbation is reduced, the mixed layer is shallow, and chemosynthesis-based nutrition (via heterotrophy and symbiosis) becomes important.

Deep, diverse and definitely different: unique attributes of the world's largest ecosystem

2010-09-22

Eva Ramírez-Llodra , Angelika Brandt , Roberto Danovaro +7 more

Abstract. The deep sea, the largest biome on Earth, has a series of characteristics that make this environment both distinct from other marine and land ecosystems and unique for the … Abstract. The deep sea, the largest biome on Earth, has a series of characteristics that make this environment both distinct from other marine and land ecosystems and unique for the entire planet. This review describes these patterns and processes, from geological settings to biological processes, biodiversity and biogeographical patterns. It concludes with a brief discussion of current threats from anthropogenic activities to deep-sea habitats and their fauna. Investigations of deep-sea habitats and their fauna began in the late 19th century. In the intervening years, technological developments and stimulating discoveries have promoted deep-sea research and changed our way of understanding life on the planet. Nevertheless, the deep sea is still mostly unknown and current discovery rates of both habitats and species remain high. The geological, physical and geochemical settings of the deep-sea floor and the water column form a series of different habitats with unique characteristics that support specific faunal communities. Since 1840, 28 new habitats/ecosystems have been discovered from the shelf break to the deep trenches and discoveries of new habitats are still happening in the early 21st century. However, for most of these habitats the global area covered is unknown or has been only very roughly estimated; an even smaller – indeed, minimal – proportion has actually been sampled and investigated. We currently perceive most of the deep-sea ecosystems as heterotrophic, depending ultimately on the flux on organic matter produced in the overlying surface ocean through photosynthesis. The resulting strong food limitation thus shapes deep-sea biota and communities, with exceptions only in reducing ecosystems such as inter alia hydrothermal vents or cold seeps. Here, chemoautolithotrophic bacteria play the role of primary producers fuelled by chemical energy sources rather than sunlight. Other ecosystems, such as seamounts, canyons or cold-water corals have an increased productivity through specific physical processes, such as topographic modification of currents and enhanced transport of particles and detrital matter. Because of its unique abiotic attributes, the deep sea hosts a specialized fauna. Although there are no phyla unique to deep waters, at lower taxonomic levels the composition of the fauna is distinct from that found in the upper ocean. Amongst other characteristic patterns, deep-sea species may exhibit either gigantism or dwarfism, related to the decrease in food availability with depth. Food limitation on the seafloor and water column is also reflected in the trophic structure of heterotrophic deep-sea communities, which are adapted to low energy availability. In most of these heterotrophic habitats, the dominant megafauna is composed of detritivores, while filter feeders are abundant in habitats with hard substrata (e.g. mid-ocean ridges, seamounts, canyon walls and coral reefs). Chemoautotrophy through symbiotic relationships is dominant in reducing habitats. Deep-sea biodiversity is among of the highest on the planet, mainly composed of macro and meiofauna, with high evenness. This is true for most of the continental margins and abyssal plains with hot spots of diversity such as seamounts or cold-water corals. However, in some ecosystems with particularly "extreme" physicochemical processes (e.g. hydrothermal vents), biodiversity is low but abundance and biomass are high and the communities are dominated by a few species. Two large-scale diversity patterns have been discussed for deep-sea benthic communities. First, a unimodal relationship between diversity and depth is observed, with a peak at intermediate depths (2000–3000 m), although this is not universal and particular abiotic processes can modify the trend. Secondly, a poleward trend of decreasing diversity has been discussed, but this remains controversial and studies with larger and more robust data sets are needed. Because of the paucity in our knowledge of habitat coverage and species composition, biogeographic studies are mostly based on regional data or on specific taxonomic groups. Recently, global biogeographic provinces for the pelagic and benthic deep ocean have been described, using environmental and, where data were available, taxonomic information. This classification described 30 pelagic provinces and 38 benthic provinces divided into 4 depth ranges, as well as 10 hydrothermal vent provinces. One of the major issues faced by deep-sea biodiversity and biogeographical studies is related to the high number of species new to science that are collected regularly, together with the slow description rates for these new species. Taxonomic coordination at the global scale is particularly difficult, but is essential if we are to analyse large diversity and biogeographic trends.

View PDF Chat

DNA primers for amplification of mitochondrial cytochrome c oxidase subunit I from diverse metazoan invertebrates.

1994-10-01

OLE FOLMER , Michael B. Black , Walter R. Hoeh +2 more

We describe "universal" DNA primers for polymerase chain reaction (PCR) amplification of a 710-bp fragment of the mitochondrial cytochrome c oxidase subunit I gene (COI) from 11 invertebrate phyla: Echinodermata, … We describe "universal" DNA primers for polymerase chain reaction (PCR) amplification of a 710-bp fragment of the mitochondrial cytochrome c oxidase subunit I gene (COI) from 11 invertebrate phyla: Echinodermata, Mollusca, Annelida, Pogonophora, Arthropoda, Nemertinea, Echiura, Sipuncula, Platyhelminthes, Tardigrada, and Coelenterata, as well as the putative phylum Vestimentifera. Preliminary comparisons revealed that these COI primers generate informative sequences for phylogenetic analyses at the species and higher taxonomic levels.

The ecology of marine nematodes

1985-01-01

C.H.R. Heip , Magda Vincx , G. Vranken

The Mesozoic marine revolution: evidence from snails, predators and grazers

1977-01-01

Geerat J. Vermeij

Tertiary and Recent marine gastropods include in their ranks a complement of mechanically sturdy forms unknown in earlier epochs. Open coiling, planispiral coiling, and umbilici detract from shell sturdiness, and … Tertiary and Recent marine gastropods include in their ranks a complement of mechanically sturdy forms unknown in earlier epochs. Open coiling, planispiral coiling, and umbilici detract from shell sturdiness, and were commoner among Paleozoic and Early Mesozoic gastropods than among younger forms. Strong external sculpture, narrow elongate apertures, and apertural dentition promote resistance to crushing predation and are primarily associated with post-Jurassic mesogastropods, neogastropods, and neritaceans. The ability to remodel the interior of the shell, developed primarily in gastropods with a non-nacreous shell structure, has contributed greatly to the acquisition of these antipredatory features. The substantial increase of snail-shell sturdiness beginning in the Early Cretaceous has accompanied, and was perhaps in response to, the evolution of powerful, relatively small, shell-destroying predators such as teleosts, stomatopods, and decapod crustaceans. A simultaneous intensification of grazing, also involving skeletal destruction, brought with it other fundamental changes in benthic community structure in the Late Mesozoic, including a trend toward infaunalization and the disappearance or environmental restriction of sessile animals which cannot reattach once they are dislodged. The rise and diversification of angiosperms and the animals dependent on them for food coincides with these and other Mesozoic events in the marine benthos and plankton. The new predators and prey which evolved in conjunction with the Mesozoic reorganization persisted through episodes of extinction and biological crisis. Possibly, continental breakup and the wide extent of climatic belts during the Late Mesozoic contributed to the conditions favorable to the evolution of skeleton-destroying consumers. This tendency may have been exaggerated by an increase in shelled food supply resulting from the occupation of new adaptive zones by infaunal bivalves and by shell-inhabiting hermit crabs. Marine communities have not remained in equilibrium over their entire geological history. Biotic revolutions made certain modes of life obsolete and resulted in other adaptive zones becoming newly occupied.

The Ecology of Deep-Sea Hydrothermal Vents

2000-12-31

Cindy Lee Van Dover

Chemical Oceanography

1976-01-01

Introduction to the study of meiofauna

1989-04-01

SIO Benthic Invertebrate Collection

2019-01-01

Charlotte Seid

The Scripps Institution of Oceanography Benthic Invertebrate Collection (SIO-BIC) is a research repository housing more than 50,000 lots, representing more than 800,000 specimens and more than 7,600 species from marine … The Scripps Institution of Oceanography Benthic Invertebrate Collection (SIO-BIC) is a research repository housing more than 50,000 lots, representing more than 800,000 specimens and more than 7,600 species from marine environments worldwide. The Collection includes extensive holdings from deep-sea environments (>1,000 m), chemosynthetic ecosystems (hydrothermal vents, hydrocarbon seeps, whale falls), Antarctica, and the eastern Pacific. Materials have been collected through a range of techniques, from intertidal hand collecting and SCUBA to trawls and deep-sea submersibles. SIO-BIC contains more than 700 type lots and considerable material properly preserved for genomic studies (95% ethanol and ultracold storage). Multiple preparation types are often available for each lot (e.g., fluid voucher, ethanol subsample, dry material). The searchable electronic database, including a map search feature and specimen images, is updated weekly and publicly accessible online at http://tinyurl.com/siobic. SIO-BIC supports scientific research by providing specimens for study of the taxonomy, biogeography, and evolution of benthic invertebrates, including the description of many new species. Specimens are available for examination at Scripps and for loan to researchers at recognized institutions worldwide, consistent with our loan policies. Collection staff and materials also support education and public outreach via undergraduate and graduate classes, school programs, guest lectures, artist collaborations, and exhibits and events at the Birch Aquarium.

The Biology of Calanoid Copepods

1998-01-01

J. Mauchline

A new species of Eurythenes (Crustacea: Amphipoda) from abyssal depths in the Peru-Chile Trench.

2025-06-25

Jennifer A. Wainwright , Johanna N. J. Weston , Todd Bond +1 more | Zootaxa

Eurythenes S.I. Smith in Scudder, 1882 (Crustacea: Amphipoda) are large amphipods found from shallow polar waters to the bottom of subduction trenches. They are key members of the benthopelagic scavenging … Eurythenes S.I. Smith in Scudder, 1882 (Crustacea: Amphipoda) are large amphipods found from shallow polar waters to the bottom of subduction trenches. They are key members of the benthopelagic scavenging guild in the deep sea and can swarm baited lander traps. A commonly documented species, Eurythenes gryllus (Lichtenstein in Mandt, 1822) was once considered a widespread cosmopolitan species, but is now recognised as a species complex, with five described cryptic lineages and several others identified but undescribed. One documented but undescribed species has been incorporated into phylogenetic studies as Eurythenes sp. “Peru-Chile Abyssal”. Herein, we formally describe Eurythenes inti sp. nov. as the 11th species within the genus. This species was sampled from 4602 to 6173 m water depth in the northern section of the Peru-Chile Trench, known as the Milne-Edwards sector, during the RV Sonne expedition SO209 in 2010. Eurythenes inti sp. nov. expresses key morphological traits that are diagnostic to this species, including the shape of coxa 2, the dorsal ridging from pereonite 5 to urosomite 1, the subchelate shape of the gnathopod 2 palm, and the three non-protruding nodular spines on the maxilliped inner plate. These morphological features diagnose Eurythenes inti sp. nov. to further clarify this cryptic genus.

Two new species of Vemana Barnard, 1964 (Crustacea, Amphipoda, Vemanidae) from abyssal depths in the eastern tropical Atlantic Ocean

2025-06-25

Ed A. Hendrycks , Michael H. Thurston | Zootaxa

Sampling at abyssal depths in the eastern tropical Atlantic Ocean has provided six specimens of the rarely collected amphipod genus Vemana (Crustacea, Amphipoda, Amphilochidea, Alicelloidea, Vemanidae). These new collections represent … Sampling at abyssal depths in the eastern tropical Atlantic Ocean has provided six specimens of the rarely collected amphipod genus Vemana (Crustacea, Amphipoda, Amphilochidea, Alicelloidea, Vemanidae). These new collections represent two distinct entities which are fully illustrated and described herein as Vemana cuspidata sp. nov. and Vemana hortonae sp. nov. With the addition of the new material, the total number of known specimens is increased by 67%. The five species currently accepted in the genus are diagnosed and a key to all seven species is provided.

Phylogenomic analyses of Pliocardiinae (Bivalvia: Vesicomyidae) update genus‐level taxonomy and shed light on trait evolution

2025-06-23

Kexin Gao , Xing He , H. Wang +7 more | Cladistics

Vesicomyid clams in the subfamily Pliocardiinae are chemosymbiotic and specific to deep-sea chemosynthetic ecosystems with wide bathymetric and geographic ranges, making them a suitable model to study molecular adaptation and … Vesicomyid clams in the subfamily Pliocardiinae are chemosymbiotic and specific to deep-sea chemosynthetic ecosystems with wide bathymetric and geographic ranges, making them a suitable model to study molecular adaptation and biogeography. Its phylogeny, however, still remains contentious due to limited molecular markers. Here, we elucidate the evolutionary relationships among pliocardiines based on phylogenomics data. By testing a wide range of matrices with methods including maximum likelihood, maximum parsimony, Bayesian inference, and a coalescent approach, we present a robust phylogenomic tree at the genus level supported by AU-test and GLS analyses. We revise the genus-level taxonomy of pliocardiines updating from Johnson et al. (Syst. Biodivers. 2017, 15, 346) synonymising a number of species in the "gigas-group" with Archivesica-also supported by a mitogenome phylogeny. Our fossil-calibrated tree based on the phylogenomic backbone reveals that Pliocardiinae originated earlier than [41.06, 42.00] Ma in the middle Eocene, while its diversification has been concurrent with global climatic cooling events. Ancestral state reconstruction analyses found two independent invasions into the abyssal zone, and a shift from harbouring the Ca. Ruthia symbionts to Ca. Vesicomyosocius symbionts. Our results present a solid backbone for future investigations into molecular adaptation, biogeography and symbiosis in this fascinating group of molluscs.

Interconnected robotic platforms inform deep-sea ecological restoration trends

2025-06-23

Ivan Masmitjà Rusiñol , Narcís Palomeras , Daniel Mihai Toma +7 more | Marine Pollution Bulletin

Rare Evolutionary Events Support the Phylogenetic Placement of Orthonectida Within Annelida

2025-06-21

O. V. Nikolaeva , Kirill V. Mikhailov , Maria S. Muntyan +5 more | International Journal of Molecular Sciences

Orthonectids are a group of highly simplified worm-like parasites that are placed within Lophotrochozoa by multigene mitochondrial and nuclear phylogenies. However, their exact position within Lophotrochozoa is uncertain due to … Orthonectids are a group of highly simplified worm-like parasites that are placed within Lophotrochozoa by multigene mitochondrial and nuclear phylogenies. However, their exact position within Lophotrochozoa is uncertain due to the high rate of molecular evolution and putative long branch attraction artifacts. To examine the phylogenetic placement of orthonectids, we applied an alternative approach that takes into account rare evolutionary events (gene order rearrangements in mitochondrial DNA and individual changes in mitochondrial proteins) with an assessment of their probabilities based on a reference sequence database (RefSeq, NCBI). This approach strongly supports the branching of orthonectids among annelids, but does not conclusively resolve their position among the annelid taxa.

Ribbon worms living on deep-sea trees: Alvinonemertes daitoensis sp. nov. (Nemertea, Monostilifera) associated with the glass sponge Walteria leuckarti (Porifera, Hexactinellida)

2025-06-20

Natsumi Hookabe , Geminne G. Manzano , Naoto Jimi +4 more | Systematics and Biodiversity

Life at oxygen minimum zone: bacterial symbiosis in the gills of the bivalve Kelliella miliaris

2025-06-20

Olga Utrilla , Enrique Viguera , Serge Gofas +3 more | Frontiers in Marine Science

Kelliella miliaris (Philippi, 1844) is a minute bivalve, living on the surface of soft sediments, from the continental shelf to bathyal depths, commonly in the oxygen minimum zones (OMZ) and/or … Kelliella miliaris (Philippi, 1844) is a minute bivalve, living on the surface of soft sediments, from the continental shelf to bathyal depths, commonly in the oxygen minimum zones (OMZ) and/or in reducing habitats. The scarcity of data on the biology of Kelliella prompted us to investigate, at ultrastructural level, specimens found in southern Spain. Kelliella miliaris shows several morphological characteristics that would be adaptive for living in the OMZ: (1) presence of numerous muscular fibers in the mantle, mantle edge and gills-visceral mass connection; all of which would allow to actively move the gills and/or enable a better control of the ventral opening in relation to vertical movements of the animal; (2) high number (in relation to body size) and large size of gill filaments, mainly in the large inner demibranch; and (3) long cilia which would provide a large surface for capture of oxygen and a highly effective uptake of oxygen from water. We have observed in all the specimens examined the presence of numerous rod shaped bacteria among the gill cilia. These bacteria show the typical double membrane of Gram-negative bacteria. The analysis of the bacterial DNA revealed that Gammaproteobacteria is the most abundant class, with 53.69% of total reads. The latter, together with the peak of oxygen and the presence of sulfur inside the electron dense granules from the bacteria, determined by TEM-EDX analysis, point to the involvement of these bacteria in the oxidization of the sulfide to thiosulfate. The presence of bacteria in the gills of Kelliella miliaris highlights the importance of the chemosynthetic symbiosis in the OMZs of the oceans that has been probably overlooked up to now. The presence of different microorganisms in the stomach indicates heterotrophy. We have found spermatozoids inside the female gonad, which confirms internal fertilization in K. miliaris . However, the presence of protoconch I and protoconch II, indicates planktotrophic larval development.

Comparison of Kızılırmak and Yeşilırmak (Southern Black Sea) estuarine ecosystems based on macrobenthic biodiversity and environmental variables and new records for the macroinvertebrate fauna of Turkey

2025-06-20

Melih Rüzgar , Aysun Gümüş | Aquatic Sciences

Abstract This study investigates the Kızılırmak and Yeşilirmak estuarine ecosystems in Turkey, which provide significant freshwater and nutrient inputs to the Samsun Shelf area along the midsouthern Black Sea. The … Abstract This study investigates the Kızılırmak and Yeşilirmak estuarine ecosystems in Turkey, which provide significant freshwater and nutrient inputs to the Samsun Shelf area along the midsouthern Black Sea. The objective was to determine the current ecological status and to detect any significant differences between two estuarine ecosystems (restored—Kızılırmak—and natural—Yeşilırmak) in terms of macrobenthic invertebrates and environmental variables. Macrobenthic invertebrates were collected with a 500 µm mesh size kick-net. A total of four samplings, one in each season, were collected during February, May, August, and November of 2017. A total of 90 taxa, mainly oligochaetas and chironomids, were identified, composed of 51 species in Kızılırmak and 60 in Yeşilırmak. Orthocladius (Orthocladius) dentifer , O. (O.) clarkei , O. (O.) dorenus , O. (O.) wetterenesis , O. (O.) mixtus , and Mystacides longicornis were found to be new records for Turkey. The distribution of macrobenthic invertebrates was compared between season, estuary, grain size and stations. In Kızılırmak and Yeşilırmak, the region characterized as estuarine was found to be small transitional waters. In Kızılırmak, a high similarity was observed among stations, accompanied by relatively low diversity across sampling sites. This phenomenon is thought to be a natural consequence of the reconstruction activities along the river, which have deleteriously affected the ecosystem. The Yeşilırmak estuary has a more diverse macrobenthic community and appeared to be better preserved than the Kızılırmak area.

Benthic Infauna in the Shallow-Water Hydrothermal System of Banderas Bay, Mexico: A Two-Period Comparison

2025-06-20

María Carolina Rodríguez-Uribe , Rosa María Chávez Dagóstino , Patricia Salazar-Silva +3 more | Diversity

At a depth of approximately 9 m off the coast of Banderas Bay, hydrothermal activity occurs through various seabed vents, discharging liquids and gases that reach temperatures of up to … At a depth of approximately 9 m off the coast of Banderas Bay, hydrothermal activity occurs through various seabed vents, discharging liquids and gases that reach temperatures of up to 89 °C and pH values lower than the surrounding seawater. This study examines the composition of the benthic infauna inhabiting the sediments of this hydrothermal system in two time periods: November 2017 (previously reported) and September 2023 (recorded for this study). In total, for both samplings, we identified 17 benthic infaunal groups—amphipods, isopods, cumaceans, tanaidaceans, crabs, shrimps, copepods, snails, limpets, caecids, chitons, bivalves, scaphopods, polychaetes, amphioxus, ophiuroids, and bryozoans—belonging to these ten taxonomic classes: Malacostraca, Maxillopoda, Gastropoda, Polyplacophora, Bivalvia, Scaphopoda, Polychaeta, Leptocardii, Ophiuroidea, and Stenolaemata. Additionally, we identified galleries of polychaetes, vermetids, and peracarids. Despite the stressful hydrothermal conditions, statistical analyses of both sampling campaigns revealed no significant differences in abundance, highlighting the potential persistence and adaptability of benthic communities in hydrothermally influenced habitats.

Sea slugs (Gastropoda: Heterobranchia) from Huatulco: new records and distribution range extensions for Oaxaca, Mexico

2025-06-20

Oscar Iván González-Romero , Xochitl G. Vital | Revista Mexicana de Biodiversidad

While the diversity of sea slugs in the northern area of the Pacific coast of Mexico has been studied thoroughly in the last decades, little is known about the composition … While the diversity of sea slugs in the northern area of the Pacific coast of Mexico has been studied thoroughly in the last decades, little is known about the composition of species in the southern states of Mexico. Several field trips were made in 5 localities of Bahías de Huatulco, Oaxaca, where specialized sampling methods focused on sea slugs were carried out. Herein, we documented 49 species of sea slugs, including 37 new records for the state, which increases to 58 species the total sea slug richness known for Oaxaca. This study updates the inventory of sea slugs for the Mexican Pacific coast and contributes to the knowledge of the marine fauna of the Natural Protected Area “Parque Nacional Huatulco”.

A new species of Pseudechinopsyllus George, 2006 (Copepoda, Harpacticoida, Cletodidae) from Campos Basin, Brazil (southwest Atlantic Ocean), with remarks on the phylogeny of the genus

2025-06-19

Kai Horst George , Adriane Pereira Wandeness , Paulo Jorge Parreira dos Santos | ZooKeys

The discovery and description of a new representative of the Ceratonotus group (Copepoda, Harpacticoida, Cletodidae T. Scott) in the Grussaí Canyon off the coast of Brazil opened up the possibility … The discovery and description of a new representative of the Ceratonotus group (Copepoda, Harpacticoida, Cletodidae T. Scott) in the Grussaí Canyon off the coast of Brazil opened up the possibility of clarifying the relationship between Echinopsyllus Sars and Pseudechinopsyllus George. Pseudechinopsyllus andrei sp. nov. is characterised by several autapomorphies, including (a) the extensive development of long spinules on the second and third segment of the female antennule, and the strong respectively extreme elongation of (b) the exopod and (c) the setophore on the female P5. Synapomorphies shared with P. sindemarkae include (d) the formation of long spinules at the bases of P2–P4 as well as (e) on exp1 of the P2, and (f) the strong elongation of a tube pore on P2 exp2. Furthermore, the sister group relationship of Pseudechinopsyllus and Echinopsyllus could be substantiated by eleven synapomorphies, among them (g) the large body size, (h) the development of long, rigid cephalothoracic ventrolateral anterior and posterior processes and (i) the loss of the syncoxal seta on the maxilliped. The present study represents a further step towards clarifying the systematic relationships within the Ceratonotus group. A key to the species is provided.

The effect of collinearity between observed and model derived training variables on estuarine algal species distribution models

2025-06-19

Dante M. L. Horemans , Jing-Xian Lin , Marjorie A. M. Friedrichs +3 more | Ecological Informatics

Description of a new species of Pseudobornella Baba, 1932 (Gastropoda, Nudibranchia, Dendronotidae) from the Yellow Sea

2025-06-18

Shuqian Zhang , J.Z. Wang | ZooKeys

The genus Pseudobornella Baba, 1932 (Gastropoda, Nudibranchia, Dendronotidae), which was previously thought to be monotypic and restricted to the Western Pacific, is here expanded with the description of a second … The genus Pseudobornella Baba, 1932 (Gastropoda, Nudibranchia, Dendronotidae), which was previously thought to be monotypic and restricted to the Western Pacific, is here expanded with the description of a second species, Pseudobornella qingdaoensis sp. nov. , discovered in the Yellow Sea, China. The new species is similar in general body shape to its sole congener, P. orientalis Baba, 1932, but these species can be distinguished based on both external morphology and internal anatomy. Phylogenetic analyses reconstructed by Bayesian inference and maximum-likelihood methods using concatenated mitochondrial (COI, 16S rRNA) and nuclear (H3) genes and species delimitation analyses support the monophyly of Pseudobornella as well as the separation of the two known species.

Revision of the genus Turrancilla (Neogastropoda: Olivoidea: Ancillariidae) in an integrative taxonomy framework

2025-06-18

Yuri I. Kantor , GIORGIO STRANO , FRED VERVAET +2 more | Zootaxa

Turrancilla, a small genus of Ancillariidae, is revised based on molecular (partial cox1 sequences) and morphological data. Six species are attributed to the genus based on both molecular and morphological … Turrancilla, a small genus of Ancillariidae, is revised based on molecular (partial cox1 sequences) and morphological data. Six species are attributed to the genus based on both molecular and morphological evidence, including one new species, T. heraldei sp. nov., from the Philippines. Two additional species are included based on morphological data alone. The status of one of these, T. apicalis Kira, 1959, from Japan, remains uncertain pending further data. One species, T. williamsoni Petuch, 1987, is excluded and provisionally assigned to Amalda. In conchological characteristics, Turrancilla can closely resemble Amalda but is readily distinguished by its radular features. The genus is primarily confined to upper bathyal depths of the Pacific, with one species, T. akontistes reaching western Indian Ocean (from Zanzibar to Mozambique and Madagascar) and one, T. sibuetae, recorded in the eastern Atlantic.

Prioritisation of ocean biodiversity data collection to deliver a sustainable ocean

2025-06-18

Amelia E.H. Bridges , Kerry L. Howell | Communications Earth & Environment

Intraspecific differences in habitat depth in a deep-sea isopod, Bathynomus doederleini (Crustacea: Isopoda: Cirolanidae), off the west coast of Kyushu, Japan

2025-06-18

Saori Anzai , Shogo Tanaka , Shimpei Tsuchida +7 more | bioRxiv (Cold Spring Harbor Laboratory)

Abstract The giant deep-sea isopod, Bathynomus doederleini , is a benthic scavenger distributed in the northwestern Pacific. Despite its ecological importance, little is known about its habitat use and intraspecific … Abstract The giant deep-sea isopod, Bathynomus doederleini , is a benthic scavenger distributed in the northwestern Pacific. Despite its ecological importance, little is known about its habitat use and intraspecific variation in body size in relation to depth. In this study, we examined the habitat depth, size structure, and distributional limits of B. doederleini off the western coast of Kyushu, Japan, using baited traps deployed at depths ranging from 151 to 821 m. A total of 1,152 individuals were collected, with the highest catch per unit effort (CPUE) observed between 300 and 500 m. CPUE declined sharply below 700 m, likely due to thermal constraints and interspecific competition. Body size distribution varied significantly with depth: minimum body size increased with depth, while maximum body size remained constant. Smaller individuals were more abundant in shallower, warmer waters, suggesting ontogenetic habitat segregation possibly driven by metabolic and competitive factors. No brooding individuals were captured, supporting previous findings that reproductive females avoid baited traps. These results suggest that B. doederleini forms a reproductively active population in the East China Sea, with ecological adaptations to thermal conditions and depth-related niche partitioning. This study highlights the importance of trap type and environmental gradients in understanding deep-sea species ecology.

Changes in a macrozoobenthic assemblage after beach nourishment based on local knowledge in a brackish lagoon

2025-06-17

Yasushi Miyamoto , Gen Kanaya , Masanori Taru +3 more | Ecological Research

New record of Ficopomatus uschakovi (Pillai, 1960) (Polychaeta: Serpulidae) from the Northern Bay of Bengal, India: A multivariate approach

2025-06-16

Mihir Bose , Santanu Mitra | Species

The tidepool alga Cystoseira humilis on an oceanic island exhibits partial adherence to Taylor’s Law.

2025-06-16

Ángela Gómez-Alcañíz , Rodrigo Riera | Vieraea Folia scientiarum biologicarum canariensium

Taylor’s Law is an empirical relationship between the variance (s2) and the mean (m) of abundance estimates described by the equation s2 = amb, where b is the aggregation index. … Taylor’s Law is an empirical relationship between the variance (s2) and the mean (m) of abundance estimates described by the equation s2 = amb, where b is the aggregation index. From this relationship it is possible to quantify the degree of aggregation. The present study checks the validity of Taylor’s Law using a benthic species, Cystoseira humilis in the intertidal pools of the island of Gran Canaria (NE Atlantic Ocean). Eight intertidal pools were sampled in three locations with a 25 x 25 cm grid. Thallus abundance and small, medium and large scale spatial variation were determined. The total number of thalli samples was 24,329 among the eight studied tide pools. The shallower the tide pool, the fewer thalli per stipe were found. Cystoseira humilis showed a regular distribution, and was not fully adapted to Taylor’s Law.

Community Structure of Benthic Macroinvertebrates in Jose Abad Santos, Davao Occidental, Philippines

2025-06-16

Jhun Rheil H Molina , Junior Ronilo Muda , Rafael A. Cruz | Davao Research Journal

Macroinvertebrates play a vital role in energy transfer and nutrient cycling in marine ecosystems and serve as important sources of food and livelihood for coastal communities. However, these critical resources … Macroinvertebrates play a vital role in energy transfer and nutrient cycling in marine ecosystems and serve as important sources of food and livelihood for coastal communities. However, these critical resources are currently under threat due to uncontrolled harvesting and habitat degradation. This study aimed to provide valuable information on the community structure of benthic macroinvertebrates within the marine protected area (MPA) of Butulan and the open-access area of Balangonan in Jose Abad Santos, Davao Occidental. Sampling was conducted using the belt transect method. A total of 749 individuals, representing 27 species were recorded across the two sites, with gastropods comprising the majority of species. The mean (± SE) population density was significantly higher in Butulan, at 3,540 ± 701.52 ind ha-1, compared to 1,560 ± 246.36 ind ha-1 in Balangonan (t = 3.25, P = 0.02). Diversity index results indicated significantly higher species diversity in Butulan (H' = 3.04, Hmax = 3.30) than in Balangonan (H' = 2.45, Hmax = 2.64) (t = 4.65, P = 0.001), with species evenly distributed and no single species dominating both sites. The higher density and diversity of benthic macroinvertebrates in Butulan may be attributed to the strict protection of the MPA by the local government. In contrast, unregulated collection in the open-access area of Balangonan likely contributed to its lower diversity and density. Regulatory measures such as catch limits, size quotas, restrictions on harvesting juveniles and gravid individuals, and stock enhancement should be implemented to ensure the sustainable use of this important resource.

A new species of the feather star Capillaster within C. multiradiatus species complex (Crinoidea, Comatulidae) in Palau and the Great Barrier Reef

2025-06-15

David L. Meyer , Anne K. Hoggett , Danwei Huang +4 more | Zootaxa

The feather star Capillaster AH Clark, 1909 (Crinoidea, Comatulidae) is a common feather star on coral reefs of the entire Indo-West Pacific region ranging from the Red Sea in the … The feather star Capillaster AH Clark, 1909 (Crinoidea, Comatulidae) is a common feather star on coral reefs of the entire Indo-West Pacific region ranging from the Red Sea in the west to reefs of the central Pacific. Extensive studies of crinoids from the 1970s to 2000s by SCUBA diving encountered Capillaster, identified as C. multiradiatus (L., 1758) on reefs in the Palau Islands, Micronesia, and around Lizard Island (northern Great Barrier Reef [GBR], central GBR reefs (Rib Reef, John Brewer Reef, Davies Reef), reefs at Heron Island (southern GBR), and other sites within the Coral Triangle of the Ind-West Pacific. At Lizard Island and some other GBR reefs, two morphotypes co-occur in close proximity, both identified as C. multiradiatus using existing taxonomic keys, one collected by SCUBA during daytime dives when the crinoids were fully exposed and forming feeding postures and the other emergent and forming a filtration fan only at night on the same reefs where the other form occurred. The Palau form was collected exclusively when emergent at night and forming a feeding fan. Molecular genetic analysis using cytochrome oxidase c subunit I (COI) shows that the Palau crinoids cluster with the nocturnally emergent Capillaster at GBR. Diurnally emergent Capillaster at GBR sites are distinct in COI analysis from sympatric nocturnally emergent specimens and also in newly recognized skeletal morphologic characters and distinct color variation. We utilize molecular genetic data, traditional skeletal morphology, coloration, along with differences in emergence and feeding habits to describe a new species, Capillaster crypticus sp. nov.,which is currently known from Palau reefs and GBR reefs. A single specimen collected in daytime at Raja Ampat, Indonesia, clustered with C. crypticus on COI yet we could not confirm whether it lacks the indentation in the center of the centrodorsal. This new species represents another example of “hidden diversity” among the species-rich feather star crinoid faunas of the Indo-West Pacific region. Our data emphasize the importance of utilizing all available data: genetic, skeletal morphologic, color and pattern, ecologic, behavioral, and reproductive in distinction of crinoid species.

A morphological character matrix describing shells from extant and extinct lucinid bivalves of the Western Atlantic

2025-06-15

Brooke Long-Fox | Historical Biology

First report of a giant protist Tricranastrum trinibrachium Takahashi 1991 (syn. Myelastrum trinibrachium) from the Indian Ocean

2025-06-13

D. Prabin Dora , E P Harshitha , Biraja Kumar Sahu | Journal of Plankton Research

ABSTRACT Rhizarians play an important role in ocean biogeochemistry and are used as paleoproxies. These organisms, specifically the giant ones, which are fragile in nature, are poorly studied and understood. … ABSTRACT Rhizarians play an important role in ocean biogeochemistry and are used as paleoproxies. These organisms, specifically the giant ones, which are fragile in nature, are poorly studied and understood. A rhizarian species Tricranastrum trinibrachium Takahashi 1991 (syn. Myelastrum trinibrachium Takahashi 1991), class Polycystine, order Spumellaria, Family Euchitoniidae was recorded for the first time in the Indian Ocean in plankton samples from the Arabian Sea. The species size ranged from 747 to 1575 μm. Until now, it has only been reported in the Pacific Ocean.

Evaluating Mathematical Concordance Between Taxonomic and Functional Diversity Metrics in Benthic Macroinvertebrate Communities

2025-06-13

Gonzalo Sotomayor , Henrietta Hampel , Raúl F. Vázquez +3 more | Biology

Understanding the structural concordance between taxonomic and functional diversity (FD) metrics is essential for improving the ecological interpretation of community patterns in biomonitoring programs. This study evaluated the concordance between … Understanding the structural concordance between taxonomic and functional diversity (FD) metrics is essential for improving the ecological interpretation of community patterns in biomonitoring programs. This study evaluated the concordance between taxonomic and FD metrics of benthic macroinvertebrates along a fluvial habitat quality gradient in the Paute River Basin, Ecuador. Macroinvertebrate communities were sampled over six years at twelve sampling points and assessed using four taxonomic metrics: Shannon diversity (H), the Margalef index (DMg), family richness (N), and the Andean Biotic Index (ABI). Functional diversity was evaluated using four metrics: weighted functional dendrogram-based diversity (wFDc), Rao’s quadratic entropy (Rao), functional dispersion (FDis), and functional richness (FRic). The fluvial habitat index (FHI) was used as an environmental reference to evaluate diversity metric responses. K-means clustering was independently applied to each metric, and pairwise concordance was quantified using the Measure of Concordance (MoC) and overlap in sampling points groupings across replicates. Most metrics (except FRic and N) showed clear responsiveness to the FHI gradient, confirming their ecological relevance. Strong structural concordance was observed between H and DMg and the FD metrics Rao, FDis, and wFDc, showing that these metrics captured similar yet complementary aspects of community organization. In contrast, ABI showed marked sensitivity to the FHI gradient but low concordance with functional metrics, suggesting distinct dimensions of biological integrity not encompassed by trait-based metrics. These findings highlight the value of combining taxonomic and functional metrics to detect both broad and subtle ecological changes. Integrating metrics with differing structural properties and environmental sensitivities can enhance the robustness of freshwater biomonitoring frameworks, especially in systems undergoing ecological transition or habitat degradation.

Reproductive biology of two hydrothermal vent Cocculinidae species (Mollusca: Gastropoda) from the Arctic and Southern Ocean

2025-06-13

Calum MacNeil , Maria Baker , Jon Copley +3 more | Marine Biology