Environmental Science › Ecology

Parasite Biology and Host Interactions

Works Count: 96515

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Description

This cluster of papers explores the ecological interactions of parasites in various ecosystems, emphasizing the impact of parasites on biodiversity, disease risk, and invasive species. It delves into host-parasite interactions, molecular phylogeny, and the effects of global change on parasite ecology in the aquatic environment.

Keywords

Parasites; Ecosystem; Host-Parasite Interactions; Biodiversity; Invasive Species; Disease Risk; Community Ecology; Global Change; Molecular Phylogeny; Aquatic Environment

Helminth Infections of Humans: Mathematical Models, Population Dynamics, and Control

1985-01-01

Roy M. Anderson , Robert M. May

Parasitism: the diversity and ecology of animal parasites

2014-07-16

Timothy M. Goater , Cameron P. Goater , Gerald W. Esch

Reflecting the enormous advances made in the field over the past ten years, this text synthesizes the latest developments in the ecology and evolution of animal parasites against a backdrop … Reflecting the enormous advances made in the field over the past ten years, this text synthesizes the latest developments in the ecology and evolution of animal parasites against a backdrop of parallel advances in parasite systematics, biodiversity and life cycles. This second edition has been thoroughly revised to meet the needs of a new generation of parasitology students. Balancing traditional approaches in parasitology with modern studies in parasite ecology and evolution, the authors present basic ecological principles as a unifying framework to help students understand the complex phenomenon of parasitism. Richly illustrated with over 250 figures, the text is accompanied by case study boxes designed to help students appreciate the complexity and diversity of parasites and the scientists who study them. This unique approach, presented clearly and with a minimum of jargon and mathematical detail, encourages students from diverse backgrounds to think generally and conceptually about parasites and parasitism.

The Diversity of Parasites

2000-09-01

Robert Poulin , Sergé Morand

Parasitism is one of the most successful modes of life displayed by living organisms, as measured by how often it evolved and how many parasitic species are presently in existence. … Parasitism is one of the most successful modes of life displayed by living organisms, as measured by how often it evolved and how many parasitic species are presently in existence. Studying the diversity of parasites is particularly relevant because sympatric diversification may be important in some parasite taxa, and because of the opportunity for independent tests of evolutionary hypotheses in the many separate lineages in which parasitism evolved. Our incomplete knowledge of existing parasite species-the result of a range of phenomena that includes inadequate sampling effort or the lumping of different cryptic species under one name-is not always a major obstacle for the study of parasite diversity. Patterns in the diversity of parasites may be associated with either host or parasite characteristics. The distribution of parasite diversity among host taxa does not simply reflect the species diversity of the host taxa themselves; life history and ecological traits of hosts appear to play important roles. These may determine the likelihood that hosts are colonized by parasite species over evolutionary time. It is not yet clear whether some host traits also favor intrahost speciation and diversification of parasites, and the formation of new parasite species. Certain features of parasites may also be associated with speciation and diversification. Only parasite body size has received much attention; the patterns observed are not greatly different from those of free-living species, with small-bodied parasite taxa being more speciose than related large-bodied taxa. Epidemiological parameters such as the basic reproductive rate of parasites, or R0, can also generate predictions regarding the distribution or evolution of parasite diversity. For instance, parasite taxa characterized by high R0 values may be more speciose than related taxa with lower values of R0; such predictions remain untested. Large-scale biogeographical patterns of diversity have only been well studied for metazoan parasites of marine fish; for these parasites, latitudinal patterns can be explained by effects of temperature on speciation rates and epidemiological variables, though other causes are possible. The emphasis for future research must shift from pattern description to the elucidation of the processes responsible for the structure and diversity of parasite faunas. A better integration of ecological and historical (or phylogenetic) approaches to the study of parasite diversity should make this objective possible.

Emphasizing the ecology in parasite community ecology

2006-11-30

Amy B. Pedersen , Andy Fenton

The population dynamics of microparasites and their invertebrate hosts

1981-04-27

Roy M. Anderson , Robert M. May

We show how directly transmitted microparasites, broadly defined to include viruses, bacteria, protozoans and fungi, may regulate natural populations of invertebrate hosts. The study combines elements of conventional epidemiology (where … We show how directly transmitted microparasites, broadly defined to include viruses, bacteria, protozoans and fungi, may regulate natural populations of invertebrate hosts. The study combines elements of conventional epidemiology (where the host population is assumed constant) with elements of prey-predator studies (which conventionally emphasize how prey and predator populations may be regulated by their interaction). To this end, we construct simple models embodying the essentials of the dynamical interaction between invertebrate hosts and their directly transmitted microparasites. In successive refinements, these models include the effects of recovery and disease-induced mortality, castration or diminished reproduction of infected hosts, vertical transmission, latent periods of infection, stress-related pathogenicity, the interplay between disease and other density-dependent constraints on host population growth, and free-living infective stages. In analysing the dynamical behaviour of these models, we focus on : the possible regulation of the host population by the parasite; the basic reproductive rate of the parasite, and the way in which it affects the dynamics and the evolution of the host-parasite association; and the threshold host density and its implications for endemic or epidemic maintenance of the infection. These are examined in the light of synoptic compilations of field and laboratory data on: birth rates (and disease-induced reduction thereof), natural death rates and disease-induced death rates of hosts; latent periods and efficiencies of vertical transmission of pathogens; the rate of production and lifetime of free-living infective stages; and some characteristics of long-term cycles and of epidemic outbreaks of disease in forest insects. In particular, our models suggest that the baculovirus and microsporidian infections of many temperate forest insects will tend to produce stable cycles in host abundance and in prevalence of infection, with periods in the range 5-12 years. Enough is known about the European larch budmoth and an associated granulosis virus for us to undertake a detailed comparison between theory and data that strongly suggests that the observed 9-10 year cycles are driven by the host-parasite interaction. We also discuss the possible control of invertebrate pest species by pathogens, showing how our models could guide laboratory or field studies, to help estimate whether a given pathogen is capable of regulating the target pest population, and, if so, roughly what quantity is needed to effect a specific level of (local) control. Throughout, the emphasis is on the biological ingredients of the models, and on the biological conclusions to be drawn; mathematical details are given in appendixes.

Molecular Phylogeny of the Animal Kingdom

1988-02-12

Katharine G. Field , Gary J. Olsen , David Lane +5 more

A rapid sequencing method for ribosomal RNA was applied to the resolution of evolutionary relationships among Metazoa. Representatives of 22 classes in 10 animal phyla were used to infer phylogenetic … A rapid sequencing method for ribosomal RNA was applied to the resolution of evolutionary relationships among Metazoa. Representatives of 22 classes in 10 animal phyla were used to infer phylogenetic relationships, based on evolutionary distances determined from pairwise comparisons of the 18S ribosomal RNA sequences. The classical Eumetazoa are divided into two groups. Cnidarians arose from a protist ancestry different from the second group, the Bilateria. Within the Bilateria, an early split gave rise to Platyhelminthes (flatworms) and the coelomate lineage. Coelomates are thus monophyletic, and they radiated rapidly into four groups: chordates, echinoderms, arthropods, and eucoelomate protostomes.

Parasitology Meets Ecology on Its Own Terms: Margolis et al. Revisited

1997-08-01

Albert O. Bush , Kevin D. Lafferty , Jeffrey M. Lotz +1 more

We consider 27 population and community terms used frequently by parasitologists when describing the ecology of parasites. We provide suggestions for various terms in an attempt to foster consistent use … We consider 27 population and community terms used frequently by parasitologists when describing the ecology of parasites. We provide suggestions for various terms in an attempt to foster consistent use and to make terms used in parasite ecology easier to interpret for those who study free-living organisms. We suggest strongly that authors, whether they agree or disagree with us, provide complete and unambiguous definitions for all parameters of their studies.

Host densities as determinants of abundance in parasite communities

1998-07-22

Per Arneberg , Arne Skorping , Bryan T. Grenfell +1 more

Several epidemiological models predict a positive relationship between host population density and abundance of directly transmitted macroparasites. Here, we generalize these, and test the prediction by a comparative study. We … Several epidemiological models predict a positive relationship between host population density and abundance of directly transmitted macroparasites. Here, we generalize these, and test the prediction by a comparative study. We used data on communities of gastrointestinal strongylid nematodes from 19 mammalian species, representing examination of 6670 individual hosts. We studied both the average abundance of all strongylid nematodes within a host species, and the two components of abundance, prevalence and intensity. The effects of host body weight, diet, fecundity and age at maturity and parasite body size were controlled for directly, and the phylogenetically independent contrast method was used to control for confounding factors more generally. Host population density and average parasite abundance were strongly positively correlated within mammalian taxa, and across all species when the effects of host body weight were controlled for. Controlling for other variables did not change this. Even when looking at single parasite species occurring in several host species, abundance was highest in the host species with the highest population density. Prevalence and intensity showed similar patterns. These patterns provide the first macroecological evidence consistent with the prediction that transmission rates depend on host population density in natural parasite communities.

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Immunological modulation and evasion by helminth parasites in human populations

1993-10-01

Rick M. Maizels , D. A. P. Bundy , Murray E. Selkirk +2 more

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Keys to the cestode parasites of vertebrates.

1994-04-08

L. F. Khalil , Arlene Jones , Rod A. Bray

Most previous publications on the classification of tapeworms (cestodes) have been based on compilations from the literature and are now dated. Thus there is a real need for up-to-date keys … Most previous publications on the classification of tapeworms (cestodes) have been based on compilations from the literature and are now dated. Thus there is a real need for up-to-date keys based on the re-examination of specimens and on a re-evaluation of the characters employed in cestode taxonomy. This book fulfils this need and provides keys to enable specialists and non-specialists to identify cestodes to generic level. The keys are dichotomous and are based largely on morphological characters. The authors have re-examined many specimens, including type specimens where possible. As a result, the keys reflect new ideas and have lead to reappraisals of cestode taxonomy, particularly at family and generic level, with many reallocations and synonymies. The authors include 19 international authorities from the UK, USA, Australia, Brazil, France, Norway, Italy, Switzerland, Poland, Bulgaria and the Ukraine. The book includes approximately 1,700 illustrations and is a standard work on tapeworm identification and will be indispensable for parasitologists.

Ecosystem energetic implications of parasite and free-living biomass in three estuaries

2008-07-01

Armand M. Kuris , Ryan F. Hechinger , Jenny C. Shaw +7 more

Emerging Foodborne Trematodiasis

2005-10-01

Jennifer Keiser , Jürg Utzinger

Abstract Foodborne trematodiasis is an emerging public health problem, particularly in Southeast Asia and the Western Pacific region. We summarize the complex life cycle of foodborne trematodes and discuss its … Abstract Foodborne trematodiasis is an emerging public health problem, particularly in Southeast Asia and the Western Pacific region. We summarize the complex life cycle of foodborne trematodes and discuss its contextual determinants. Currently, 601.0, 293.8, 91.1, and 79.8 million people are at risk for infection with Clonorchis sinensis, Paragonimus spp., Fasciola spp., and Opisthorchis spp., respectively. The relationship between diseases caused by trematodes and proximity of human habitation to suitable freshwater bodies is examined. Residents living near freshwater bodies have a 2.15-fold higher risk (95% confidence interval 1.38–3.36) for infections than persons living farther from the water. Exponential growth of aquaculture may be the most important risk factor for the emergence of foodborne trematodiasis. This is supported by reviewing aquaculture development in countries endemic for foodborne trematodiasis over the past 10–50 years. Future and sustainable control of foodborne trematodiasis is discussed.

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Parasitism. The ecology and evolution of intimate interactions

2002-08-21

N.C. Sangster

The effects of environmental stress on outbreaks of infectious diseases of fishes*

1974-03-01

S. F. Snieszko

Infectious diseases of fishes occur when susceptible fishes are exposed to virulent pathogens under certain environmental stress conditions. Very little research has been carried out to show the effect of … Infectious diseases of fishes occur when susceptible fishes are exposed to virulent pathogens under certain environmental stress conditions. Very little research has been carried out to show the effect of pollution on outbreaks of infectious diseases of fishes. Therefore, examples taken from the literature were selected and reviewed to show the coincidence of infectious diseases with stress caused by temperature, eutrophication, sewage, metabolic products of fishes, industrial pollution, and pesticides.

Fish-borne parasitic zoonoses: Status and issues

2005-08-26

Jong-Yil Chai , K. Darwin Murrell , Alan J. Lymbery

The Nematode Parasites of Vertebrates

1926-04-01

Warrington Yorke , P. A. Maplestone

Processes influencing the distribution of parasite numbers within host populations with special emphasis on parasite-induced host mortalities

1982-10-01

Roy M. Anderson , David M. Gordon

SUMMARY The paper examines the factors which generate various patterns of dispersion in the distribution of parasites within their host populations. Particular emphasis is placed on the role played by … SUMMARY The paper examines the factors which generate various patterns of dispersion in the distribution of parasites within their host populations. Particular emphasis is placed on the role played by chance elements in the growth and decay of parasite populations and on the influence of different types of demographic processes. It is argued that observed distributions are dynamic, rather than static, entities generated by opposing forces, some acting to create over-dispersion and others acting to generate under-dispersion. Monte Carlo simulation experiments, based on probability models of the growth and decay of host and parasite populations, are used to study the dynamics of parasite dispersion. Attention is specifically focused on the role played by parasite-induced host mortality. It is shown that, for certain types of host–parasite associations, convex curves of mean parasite abundance in relation to age (age-intensity curves), concomitant with a decline in the degree of dispersion in the older age classes of hosts, may be evidence of the induction of host mortality by parasite infection. Empirical evidence is examined in light of this prediction. In general, however, simulation studies highlight the technical difficulties inherent in establishing clear evidence of parasite-induced host mortality from ecological studies of hosts and parasites in their natural habitats.

Sex differences in parasite infections: Patterns and processes

1996-10-01

Marlene Zuk , Kurt A. McKean

Freshwater Snails of Africa and Their Medical Importance

1995-10-01

Susan M. Bandoni , David S. Brown

The first half of this book is primarily a systematic survey of the snails, beginning with glossaries, keys for identification to genera and a checklist of species. This is followed … The first half of this book is primarily a systematic survey of the snails, beginning with glossaries, keys for identification to genera and a checklist of species. This is followed by a synopsis of species, with brief notes on ecology, distribution and parasites. Relationships are then described between snails and schistosomes and with other paras

Introduced species and their missing parasites

2003-02-01

Mark E. Torchin , Kevin D. Lafferty , Andrew P. Dobson +2 more

The importance of immune gene variability (MHC) in evolutionary ecology and conservation

2005-10-20

Simone Sommer

Abstract Genetic studies have typically inferred the effects of human impact by documenting patterns of genetic differentiation and levels of genetic diversity among potentially isolated populations using selective neutral markers … Abstract Genetic studies have typically inferred the effects of human impact by documenting patterns of genetic differentiation and levels of genetic diversity among potentially isolated populations using selective neutral markers such as mitochondrial control region sequences, microsatellites or single nucleotide polymorphism (SNPs). However, evolutionary relevant and adaptive processes within and between populations can only be reflected by coding genes. In vertebrates, growing evidence suggests that genetic diversity is particularly important at the level of the major histocompatibility complex (MHC). MHC variants influence many important biological traits, including immune recognition, susceptibility to infectious and autoimmune diseases, individual odours, mating preferences, kin recognition, cooperation and pregnancy outcome. These diverse functions and characteristics place genes of the MHC among the best candidates for studies of mechanisms and significance of molecular adaptation in vertebrates. MHC variability is believed to be maintained by pathogen-driven selection, mediated either through heterozygote advantage or frequency-dependent selection. Up to now, most of our knowledge has derived from studies in humans or from model organisms under experimental, laboratory conditions. Empirical support for selective mechanisms in free-ranging animal populations in their natural environment is rare. In this review, I first introduce general information about the structure and function of MHC genes, as well as current hypotheses and concepts concerning the role of selection in the maintenance of MHC polymorphism. The evolutionary forces acting on the genetic diversity in coding and non-coding markers are compared. Then, I summarise empirical support for the functional importance of MHC variability in parasite resistance with emphasis on the evidence derived from free-ranging animal populations investigated in their natural habitat. Finally, I discuss the importance of adaptive genetic variability with respect to human impact and conservation, and implications for future studies.

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Parasitic manipulation: where are we and where should we go?

2005-01-19

Frédéric Thomas , Shelley A. Adamo , Janice Moore

Effects of environmental change on emerging parasitic diseases

2000-11-01

Jonathan A. Patz , Thaddeus K. Graczyk , Nina Geller +1 more

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The global economic cost of sea lice to the salmonid farming industry

2009-01-01

Mark J. Costello

Anisakis simplex: from Obscure Infectious Worm to Inducer of Immune Hypersensitivity

2008-04-01

M. Audícana , Malcolm W. Kennedy

Infection of humans with the nematode worm parasite Anisakis simplex was first described in the 1960s in association with the consumption of raw or undercooked fish. During the 1990s it … Infection of humans with the nematode worm parasite Anisakis simplex was first described in the 1960s in association with the consumption of raw or undercooked fish. During the 1990s it was realized that even the ingestion of dead worms in food fish can cause severe hypersensitivity reactions, that these may be more prevalent than infection itself, and that this outcome could be associated with food preparations previously considered safe. Not only may allergic symptoms arise from infection by the parasites ("gastroallergic anisakiasis"), but true anaphylactic reactions can also occur following exposure to allergens from dead worms by food-borne, airborne, or skin contact routes. This review discusses A. simplex pathogenesis in humans, covering immune hypersensitivity reactions both in the context of a living infection and in terms of exposure to its allergens by other routes. Over the last 20 years, several studies have concentrated on A. simplex antigen characterization and innate as well as adaptive immune response to this parasite. Molecular characterization of Anisakis allergens and isolation of their encoding cDNAs is now an active field of research that should provide improved diagnostic tools in addition to tools with which to enhance our understanding of pathogenesis and controversial aspects of A. simplex allergy. We also discuss the potential relevance of parasite products such as allergens, proteinases, and proteinase inhibitors and the activation of basophils, eosinophils, and mast cells in the induction of A. simplex-related immune hypersensitivity states induced by exposure to the parasite, dead or alive.

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The genomes of four tapeworm species reveal adaptations to parasitism

2013-03-12

Isheng Jason Tsai , Magdalena Zarowiecki , Nancy Holroyd +7 more

Tapeworms (Cestoda) cause neglected diseases that can be fatal and are difficult to treat, owing to inefficient drugs. Here we present an analysis of tapeworm genome sequences using the human-infective … Tapeworms (Cestoda) cause neglected diseases that can be fatal and are difficult to treat, owing to inefficient drugs. Here we present an analysis of tapeworm genome sequences using the human-infective species Echinococcus multilocularis, E. granulosus, Taenia solium and the laboratory model Hymenolepis microstoma as examples. The 115- to 141-megabase genomes offer insights into the evolution of parasitism. Synteny is maintained with distantly related blood flukes but we find extreme losses of genes and pathways that are ubiquitous in other animals, including 34 homeobox families and several determinants of stem cell fate. Tapeworms have specialized detoxification pathways, metabolism that is finely tuned to rely on nutrients scavenged from their hosts, and species-specific expansions of non-canonical heat shock proteins and families of known antigens. We identify new potential drug targets, including some on which existing pharmaceuticals may act. The genomes provide a rich resource to underpin the development of urgently needed treatments and control. Genome sequences of human-infective tapeworm species reveal extreme losses of genes and pathways that are ubiquitous in other animals, species-specific expansions of non-canonical heat shock proteins and families of known antigens, specialized detoxification pathways, and metabolism that relies on host nutrients; this information is used to identify new potential drug targets. Tapeworms cause echinococcosis and cysticercosis, two of the most severe parasitic diseases found in humans, and both on the World Health Organization's list of neglected tropical diseases. The publication of four tapeworm genome sequences — human-infective tapeworm species Echinococcus multilocularis, E. granulosus, Taenia solium and the laboratory model Hymenolepis microstoma — and identification of potential new drug targets for treating tapeworm infections is therefore a welcome development. Analysis of the sequences provides insights into the evolution of parasitism and reveals extreme losses of genes and pathways ubiquitous in other animals on one hand and species-specific expansions of genes on the other. More than a thousand E. multilocularis proteins emerge as potential targets, and of these, close to 200 with the highest scores may be targeted with existing pharmaceuticals.

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Reconstructing mitochondrial genomes directly from genomic next-generation sequencing reads—a baiting and iterative mapping approach

2013-05-09

Christoph Hahn , Lutz Bachmann , Bastien Chevreux

We present an in silico approach for the reconstruction of complete mitochondrial genomes of non-model organisms directly from next-generation sequencing (NGS) data-mitochondrial baiting and iterative mapping (MITObim). The method is … We present an in silico approach for the reconstruction of complete mitochondrial genomes of non-model organisms directly from next-generation sequencing (NGS) data-mitochondrial baiting and iterative mapping (MITObim). The method is straightforward even if only (i) distantly related mitochondrial genomes or (ii) mitochondrial barcode sequences are available as starting-reference sequences or seeds, respectively. We demonstrate the efficiency of the approach in case studies using real NGS data sets of the two monogenean ectoparasites species Gyrodactylus thymalli and Gyrodactylus derjavinoides including their respective teleost hosts European grayling (Thymallus thymallus) and Rainbow trout (Oncorhynchus mykiss). MITObim appeared superior to existing tools in terms of accuracy, runtime and memory requirements and fully automatically recovered mitochondrial genomes exceeding 99.5% accuracy from total genomic DNA derived NGS data sets in <24 h using a standard desktop computer. The approach overcomes the limitations of traditional strategies for obtaining mitochondrial genomes for species with little or no mitochondrial sequence information at hand and represents a fast and highly efficient in silico alternative to laborious conventional strategies relying on initial long-range PCR. We furthermore demonstrate the applicability of MITObim for metagenomic/pooled data sets using simulated data. MITObim is an easy to use tool even for biologists with modest bioinformatics experience. The software is made available as open source pipeline under the MIT license at https://github.com/chrishah/MITObim.

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Patterns of macroparasite abundance and aggregation in wildlife populations: a quantitative review

1995-01-01

Darren J. Shaw , Andrew P. Dobson

SUMMARY In this paper we review the published literature on patterns of abundance and aggregation of macroparasites in wildlife host populations. We base this survey on quantitative analyses of mean … SUMMARY In this paper we review the published literature on patterns of abundance and aggregation of macroparasites in wildlife host populations. We base this survey on quantitative analyses of mean burden and a number of measures of the degree of aggregation of parasite burdens between hosts. All major parasite and vertebrate host taxa were represented in the database. Mean parasite burden was found to be log-normally distributed, indicating that all parasite burdens are regulated to some degree. In addition, all but one of the parasitic infections were aggregated with respect to their hosts, and the relationship between log mean parasite burden and log variance was found to be very strong (R 2 = 0·87). That is, for a given mean parasite burden there are constraints on the degree of variation in individual host burdens. The aggregated nature of the parasitic infections is also apparent from other measures of the degree of aggregation: prevalence – mean relationships, and the negative binomial parameter, k . Using a relatively new technique for parasitological infection data – tree-based models, as well as traditional linear models – a number of the parasitic infections was found to be associated with systematically lower or higher parasite burdens. Possible biological explanations for these and other patterns are proposed.

Homage to Linnaeus: How many parasites? How many hosts?

2008-08-12

Andrew P. Dobson , Kevin D. Lafferty , Armand M. Kuris +2 more

Estimates of the total number of species that inhabit the Earth have increased significantly since Linnaeus's initial catalog of 20,000 species. The best recent estimates suggest that there are approximately … Estimates of the total number of species that inhabit the Earth have increased significantly since Linnaeus's initial catalog of 20,000 species. The best recent estimates suggest that there are approximately 6 million species. More emphasis has been placed on counts of free-living species than on parasitic species. We rectify this by quantifying the numbers and proportion of parasitic species. We estimate that there are between 75,000 and 300,000 helminth species parasitizing the vertebrates. We have no credible way of estimating how many parasitic protozoa, fungi, bacteria, and viruses exist. We estimate that between 3% and 5% of parasitic helminths are threatened with extinction in the next 50 to 100 years. Because patterns of parasite diversity do not clearly map onto patterns of host diversity, we can make very little prediction about geographical patterns of threat to parasites. If the threats reflect those experienced by avian hosts, then we expect climate change to be a major threat to the relatively small proportion of parasite diversity that lives in the polar and temperate regions, whereas habitat destruction will be the major threat to tropical parasite diversity. Recent studies of food webs suggest that approximately 75% of the links in food webs involve a parasitic species; these links are vital for regulation of host abundance and potentially for reducing the impact of toxic pollutants. This implies that parasite extinctions may have unforeseen costs that impact the health and abundance of a large number of free-living species.

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Phylogeny and classification of the Digenea (Platyhelminthes: Trematoda)11Nucleotide sequence data reported in this paper are available in the GenBank™, EMBL and DDBJ databases under the accession numbers AY222082–AY222285.

2003-04-30

Peter D. Olson , Thomas H. Cribb , Vasyl V. Tkach +2 more

The interrelationships of all major groups of Platyhelminthes: phylogenetic evidence from morphology and molecules

1999-01-01

D. Timothy J. Littlewood , Klaus Rohde , K.A. Clough

We used a data matrix of 65 morphological characters from 25 ingroup and 6 outgroup taxa, and an alignment comprising complete 18S rDNA sequences from 82 species of parasitic and … We used a data matrix of 65 morphological characters from 25 ingroup and 6 outgroup taxa, and an alignment comprising complete 18S rDNA sequences from 82 species of parasitic and free-living Platyhelminthes and from 19 species of lower invertebrates to analyse phylogenetic relationships of various platyhelminth taxa. Of the 1358 unambiguously alignablc molecular positions, 995 were variable and 757 were phylogenctically informative (parsimony criterion); complete 18S rDNA sequences ranged in length from 1755 to 2873 bp. Main conclusions are: Ncodermata are monophylctic, and the Trematoda, Monogenca and Cestoda within them are monophylctic as well. The sister group of the Ncodermata is all the other Ncoophora; the Kalyptorhynchia, Typhloplanida, Dalyelliida and Tcmnocephalida form one clade, and the last three another. Monophyly of the Seriata is rejected, but Polycladida/ Macrostomida/Haplopharyngida are monophylctic, as arc the last two taxa. As a consequence, validity of the taxon Trepaxonemata is rejected. Further studies must show the correct position of the Acocla and Nemertodermatida. It is stressed that morphological and molecular data in some respects lead to contradictory results, for instance concerning the position of the Fecampiidac/Urastoma/Ichthyophaga and the relative position of the Lccithoepitheliata. Denser sampling of taxa for molecular data, complementary sequences from independent genes, and inclusion of additional morphological data are necessary to resolve these contradictions.

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Parasites of North American freshwater fishes

1999-12-01

A molecular evolutionary framework for the phylum Nematoda

1998-03-01

Mark Blaxter , Paul De Ley , James R. Garey +7 more

QUANTIFYING PARASITES IN SAMPLES OF HOSTS

2000-04-01

Lajos Rózsa , Jenő Reiczigel , Gábor Majoros

Whereas terminological recommendations require authors to use mean intensity or mean abundance to quantify parasites in a sample of hosts, awkward statistical limitations also force them to use either the … Whereas terminological recommendations require authors to use mean intensity or mean abundance to quantify parasites in a sample of hosts, awkward statistical limitations also force them to use either the median or the geometric mean of these measures when making comparisons across different samples. Here, we propose to reconsider this inconsistent practice by giving priority to biological realism in the interpretation of different statistical descriptors and choosing the statistical tools appropriate to our decisions. Prevalence, mean intensity, and indices of parasite distribution (such as median intensity) are suitable descriptors to quantify parasites in a sample of hosts. These measures have different biological interpretations and need different statistical methods to be compared between samples.

An Introduction to Copepod Diversity

2005-12-01

George W. Benz

Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Twitter LinkedIn Tools Icon Tools Get Permissions Cite Icon Cite Search Site Citation … Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Twitter LinkedIn Tools Icon Tools Get Permissions Cite Icon Cite Search Site Citation George W. Benz; An Introduction to Copepod Diversity. J Parasitol 1 December 2005; 91 (6): 1512–1513. doi: https://doi.org/10.1645/0022-3395-91.6.1512 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search nav search search input Search input auto suggest Search

Some modifications of the McMaster helminth egg-counting technique and apparatus.

1948-01-01

H.V. Whitlock

Histologie du Système Nerveux de Lʼhomme et des Vertébrés

1998-09-01

MNH

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Regulation and Stability of Host-Parasite Population Interactions: I. Regulatory Processes

1978-02-01

Roy M. Anderson , Robert M. May

Animal biodiversity: An outline of higher-level classification and survey of taxonomic richness

2011-01-01

Zhi‐Qiang Zhang , John N. A. Hooper , Rob Wm Van Soest +7 more

Population biology of infectious diseases: Part II

1979-08-01

Robert M. May , Roy M. Anderson

Parasitic Platyhelminthes Collections

2016-01-01

Registry-Migration.Gbif.Org

Historical and recent collections of Cestoda, Digenea and Monogenea from the MHNG, including Fuhrmann, Baer, Joyeux, Bona and Dubois collections as well as results of MHNG recent expeditions. Main strength: … Historical and recent collections of Cestoda, Digenea and Monogenea from the MHNG, including Fuhrmann, Baer, Joyeux, Bona and Dubois collections as well as results of MHNG recent expeditions. Main strength: Cyclophyllidea, Proteocephalidea, Strigeata, Polystomatidae. Numerous types.

UCM Invertebrate Paleontology

2023-01-01

Talia S. Karim

Invertebrate Paleontology Collection at the University of Colorado Museum of Natural History Invertebrate Paleontology Collection at the University of Colorado Museum of Natural History

In Vitro Antihelmintic Activity of the Hydroethanolic Leaf Extracts of Avicennia marina (White Mangroves) on Eudrilus eugeniae (African Nightcrawlers)

2025-06-25

Malacad , Magallanes , Felizarte +7 more | American Journal of Life Science and Innovation

Research is needed to determine the Avicennia marina hydroethanolic leaf extract is effective against adult E. eugeniae, despite research showing that it can eliminate helminths such as Pheretima posthuma. The … Research is needed to determine the Avicennia marina hydroethanolic leaf extract is effective against adult E. eugeniae, despite research showing that it can eliminate helminths such as Pheretima posthuma. The purpose of this study was to ascertain the hydroethanolic leaf extracts of A. marina antihelmintic effectiveness against adult E. eugeniae in vitro. Using E. eugenie adults (6–8 cm in length and 0.2–0.3 cm in breadth), the percentage vermicidal activity of three concentrations of dried crude hydroethanolic leaf extract of A. marina, 25, 50, and 75 mg/mL of distilled water, was assessed every three hours for 12 hours. Five replicates, three trials, distilled water as a negative control, and mebendazole as a positive control were all examined. According to the findings, the hydroethanolic leaf extracts of A. marina have shown antihelmintic efficacy against E. eugenie adults in vitro at doses of 50 mg/mL and 75 mg/mL utilizing Kruskal-Wallis and LSD on the 3, 6, 9, and 12 hours, with a p-value of less than .05. In both concentrations, 50 and 75mg/ml, until the 12-hour exposure to the extract, there was no discernible difference between them. In vitro antihelmintic activity was best demonstrated at 50 mg/mL for 3 hours (mean = 91.1; sd = 26.6), and the in vitro antihelminthic activity was significantly superior to that of the positive control for the same duration (mean = 2.22; sd = 8.61). The results scientifically demonstrated the antihelmintic efficacy of hydroethanolic leaf extract of A. marina against E. eugeniae and provided the foundation for testing against Ascaris, Trichuris trichiura, and hookworms.

Systemic Pathological Disorders in Juvenile Rainbow Trout (Oncorhynchus mykiss) During Ichthyophthiriosis (Ichthyophthirius multifiliis) Infestation

2025-06-24

Dmitry Nikiforov-Nikishin , Nikita Kochetkov , Svetlana Smorodinskaya +2 more | Agrarian science

The article presents the results of a comprehensive study of systemic pathological disorders in young rainbow trout ( Oncorhynchus mykiss ) under spontaneous infestation with Ichthyophthirius multifiliis . The study … The article presents the results of a comprehensive study of systemic pathological disorders in young rainbow trout ( Oncorhynchus mykiss ) under spontaneous infestation with Ichthyophthirius multifiliis . The study included clinical examination, parasitological, microbiological, haematological, biochemical and histological analyses. The intensity of invasion (II) of ichthyophthiriosis was 7.0 ± 3.4 examples per microscopic field (body surface) and 24 ± 8.9 examples per microscopic field (gills). [Or define your abbreviation]. A complex of Gram-negative bacteria was isolated from the liver of infected fish: Enterobacter sp . (20%), Citrobacter freundii (60%), Acinetobacter calcoaceticus (20%), indicating the development of secondary bacterial infection. Haematological analysis revealed a decrease in erythrocyte count to 1.05 ± 0.06 x 106 cells/µL and an increase in leucocyte count to 3.87 ± ± 0.51 x 104 cells/µL, with a relative neutrophilia (38.45 ± 0.97%). Serum biochemical analysis showed a significant increase in AST activity (750.9 ± 147.7 U/L), ALT (39.4 ± 6.7 U/L), alkaline phosphatase (467.8 ± 72.6 U/L), LDH (2557.3 ± 245.1 U/L), total protein (43.83 ± 5.31 g/L), albumin (24.12 ± 2.2 g/L) and glucose (3.11 ± 0.13 µmol/L), and urea (3.23 ± 0.62 µmol/L) concentrations. Histological analysis revealed damage to the gill epithelium, degradation of renal tubules, vacuolisation and necrosis of hepatocytes, and hypotrophy of reticuloendothelial cells of the spleen. The obtained data indicate that ichthyophthyriasis is a systemic disease leading to multi-organ disorders in rainbow trout and manifests as an associative protozoalbacterial disease.

The structural features and immunological role of biomphalysins in the snail Biomphalaria glabrata

2025-06-24

Pierre Poteaux , Aline Parpinel , Chantal Ripoll +7 more | PLoS Pathogens

Biomphalysins are β-Pore Forming Toxins (β-PFT) identified in the planorbid Biomphalaria glabrata that belong to the aerolysin-like protein family. Despite potentially diverse biochemical activities, very few eukaryotic aerolysin-related proteins have … Biomphalysins are β-Pore Forming Toxins (β-PFT) identified in the planorbid Biomphalaria glabrata that belong to the aerolysin-like protein family. Despite potentially diverse biochemical activities, very few eukaryotic aerolysin-related proteins have been extensively studied. Most of the data refers to their discovery in genomes or to transcriptional activity. The involvement of biomphalysins in the immune response of Biomphalaria glabrata has been studied previously, especially regarding biomphalysin 1, which can bind and kill Schistosoma mansoni mother sporocysts. However, the repartition of biomphalysin 1 protein in B. glabrata has yet to be defined. The transcriptional behavior of the 22 other biomphalysin genes following immune challenge also remains uncharacterized. Therefore, herein, we investigate for the first time the tissular distribution of biomphalysin 1 (and 2) in B. glabrata by histological and cytological analyses through immunofluorescence approaches, notably unveiling unexpected tissue location that are involved in biomphalysin 1 synthesis. Structural predictions of the 23 members of the family have been updated using predictions based on aminoacyl spatial pair representation (AlphaFold2), highlighting unique features of the small lobe. In addition, mass spectrometry-based proteomic data more precisely predicted the regions of post-translational cleavage of biomphalysin 1. Transcriptional activity of the biomphalysin genes was explored, after which the plasmatic presence of the biomphalysin proteins was investigated in naive and S. mansoni -infected snails. The ability of native biomphalysin 1 (and 2) to bind several cell types was also investigated and correlated with the lytic ability of plasma toward the exposed cells, highlighting the central role occupied by biomphalysin 1 (and 2) in the humoral immunity of B. glabrata .

A New Species of Halipegus (Trematoda: Derogenidae: Halipeginae) in Lithobates spectabilis (Anura: Ranidae) from Reserva de la Biosfera Barranca de Metztitlan, Hidalgo, Mexico

2025-06-24

Edgar Salvador Ramírez-Cruz , Griselda Pulido-Flores , Scott Monks +1 more | Journal of Parasitology

While surveying the parasites of the leopard frog Lithobates spectabilis in the Barranca de Metztitlán Biosphere Reserve, Hidalgo, Mexico, we found several specimens of an undescribed species of Halipegus (Trematoda: … While surveying the parasites of the leopard frog Lithobates spectabilis in the Barranca de Metztitlán Biosphere Reserve, Hidalgo, Mexico, we found several specimens of an undescribed species of Halipegus (Trematoda: Derogenidae: Halipeginae) in the buccal cavity of this species of frog. The objective of this study was to describe the new species using an integrative approach, incorporating morphological data, multivariate analyses (principal and discriminant components), and phylogenetic analyses based on partial sequences of the conserved ribosomal regions (28S rDNA) of DNA and the mitochondrial subunit of the cytochrome c oxidase I gene (COI mtDNA). The methods of maximum likelihood, Bayesian inference, and maximum parsimony were used to determine the relationships of the new species to other hemiurids. Halipegus metztitlanensis n. sp. differs from its congeners mainly by the combination of the following characters: the distance from the ventral sucker to the right anterior testis, the distance from the ventral sucker to the left posterior testis, the length and width of the ovary, the width of the left testis, the distance between the oral sucker and the ventral sucker, and the length of the egg filament. The new species was recovered as a distinct group separate from other hemiuroideans based on the 28S rDNA and COI mtDNA phylogenetic analyses. This is the first report of a hemiurid trematode infecting the endemic leopard frog in Hidalgo, México and the second species described from the country.

Ficha de Fontitrygon colarensis

2025-06-24

Ricardo de Souza Rosa , Otto Bismarck Fazzano Gadig , Patrícia Charvet +7 more | Datasets - Sistema SALVE - ICMBio

Comparative in vitro effects of novel and conventional parasiticides on Thaparocleidus vistulensis (Siwak, 1932) (Monopisthocotyla) parasitizing European catfish (Silurus glanis)

2025-06-24

Wan Muhammad Hazim Wan Sajiri , Csaba Székely , István Czeglédi +2 more | Aquaculture Reports

A Comprehensive Review of Alaria alata (Goeze 1782) (Platyhelminthes, Trematoda) in Different Animal Hosts

2025-06-23

Aneta Bełcik , Tomasz Cencek , Weronika Korpysa-Dzirba +6 more | Pathogens

This review provides a comprehensive overview of the occurrence of Alaria alata (Goeze 1782) trematodes in first, second, definitive, and paratenic hosts, including wild and domestic animals. This systematic review … This review provides a comprehensive overview of the occurrence of Alaria alata (Goeze 1782) trematodes in first, second, definitive, and paratenic hosts, including wild and domestic animals. This systematic review was conducted using two academic databases: Web of Science and Google Scholar. A total of 119 articles containing data on 18 different A. alata hosts from 30 countries were analyzed. Based on the literature review, the best-studied group were definitive hosts (Mustelidae, Canidae, and Felidae), followed by paratenic, first (snails), and second intermediate hosts (amphibians). For these key intermediate hosts—snails and frogs—the data remain sparse, highlighting a gap in understanding the possible scale of the spread of A. alata. Among definitive hosts, Canids showed a higher prevalence, reinforcing their significant role in the parasite’s spread. Additionally, some Procyonidae, Felidae, and Mustelidae have been identified as paratenic hosts, with mesocercariae localized in their muscle tissues. Considering that meat of unknown origin or meat that is insufficiently heat-treated may contribute to human infection, prevalence rates as high as 40–50% in wild boar highlight the critical need for complex research. Furthermore, this review clarifies the role of host groups in the life cycle and transmission of A. alata, providing key epidemiological information and emphasizing the importance of continued research to fill knowledge gaps.

Morphological and molecular description of Corynosoma paraevae n. sp. (Acanthocephala: Polymorphidae) juveniles from Notothenia coriiceps Richardson (Perciformes: Nototheniidae) in Argentine Islands, West Antarctica

2025-06-23

Omar M. Amin , Anshu Chaudhary , Makoto Enoki Caracciolo +5 more | Systematic Parasitology

Lagochilascariasis: A Neglected Zoonosis in the Brazilian Amazon Biome and the Role of Wildlife in Its Epidemiological Chain Amidst Anthropization

2025-06-21

Felipe Masiero Salvarani , Karoline Petrini Pinheiro da Cruz , Flávio Roberto Chaves da Silva +1 more | Tropical Medicine and Infectious Disease

Lagochilascariasis is a neglected zoonotic helminthiasis, caused by Lagochilascaris minor, characterized by a complex and not well understood transmission cycle. This parasitic disease is endemic to Latin America, particularly Brazil, … Lagochilascariasis is a neglected zoonotic helminthiasis, caused by Lagochilascaris minor, characterized by a complex and not well understood transmission cycle. This parasitic disease is endemic to Latin America, particularly Brazil, and is associated with rural and forested areas, where humans may serve as accidental hosts. The southeastern region of Pará state reports the highest number of cases, highlighting its epidemiological significance. Wildlife species, especially carnivores and rodents, play crucial roles as definitive and intermediate hosts, respectively. Although lagochilascariasis can lead to severe clinical manifestations, including chronic soft tissue infections and potential central nervous system involvement, it is likely underdiagnosed due to its similarity to fungal and bacterial diseases. The anthropization of the Amazon Biome, through deforestation and habitat fragmentation, coupled with increased human–wildlife interactions, may be influencing the epidemiology of this parasitosis. This review aims to summarize current knowledge of L. minor transmission routes, the role of wildlife in maintaining its cycle, and the impact of environmental changes on disease patterns. Such insights are vital for One Health strategies, which integrate human, animal, and environmental health approaches to mitigate the disease burden.

New Cestode of the Genera Diplopylidium (Eucestoda: Dipylidiiae) Parasitizing Felis domesticus in Maharashtra: A Morphological Study

2025-06-20

Ishrat Vasi Shaikh | Asian Journal of Research in Zoology

Diplopylidium alii n. sp. belonging to order Dilepididea is described from Felis domesticus collected from Tal. Jalna of Jalna district, M.S. India. The collected cestodes were flattened and preserved in … Diplopylidium alii n. sp. belonging to order Dilepididea is described from Felis domesticus collected from Tal. Jalna of Jalna district, M.S. India. The collected cestodes were flattened and preserved in formalin. The preserved worms were stained with Harris haematoxylene, dehydrated in alcohol and mounted in D.P.X. Figures were drawn using camera lucida. The present species has dome shaped scolex; rostellar hooks in 6 rows and 38 in number; testes medium, almost round, 215-225 (219) in number; cirrus pouch large, sickle shaped; ovary distinctly bilobed; vagina is posterior to the cirrus pouch and vitelline gland medium in size, triangular with irregular margin. The present worm has significant morphological variations to accommodate it as a new species.

New Geographic Records and Description of Sprostoniella cf. multitestis Bychowsky and Nagibina, 1967 (Monogenoidea: Capsalidae: Trochopodinae) Parasitizing the Longfin Batfish Platax teira (Fabricius) (Ephippidae) from the Coastal Waters of Queensland, Australia

2025-06-20

Delane C. Kritsky | Comparative Parasitology

Preclinical Evaluation of Fenbendazole for Controlling Gyrodactylus kobayashii (Monogenea, Gyrodactylidae) in Goldfish: Dose Optimization and Safety Assessment

2025-06-19

Jing Dong , Jiangtao Li , Yongtao Liu +4 more | Animals

This preclinical study investigated the efficacy and safety of fenbendazole, a broad-spectrum benzimidazole anthelmintic, for the treatment of Gyrodactylus kobayashii in goldfish (Carassius auratus). In vivo bath treatments demonstrated potent, … This preclinical study investigated the efficacy and safety of fenbendazole, a broad-spectrum benzimidazole anthelmintic, for the treatment of Gyrodactylus kobayashii in goldfish (Carassius auratus). In vivo bath treatments demonstrated potent, dose-dependent anthelmintic efficacy, achieving 98.58% efficacy at a concentration of 0.02 mg/L and a 48 h EC50 of 0.006 mg/L. A short-duration (6 h) bath at 0.06 mg/L, followed by an 18 h recovery period in dechlorinated water, resulted in complete parasite elimination. However, acute toxicity assay indicated a relatively narrow safety margin for prolonged bath treatments, with a 96 h LC50 of 0.039 mg/L, highlighting the need for caution when employing extended bath treatments. Oral administration of fenbendazole at 20 mg/kg body weight for three consecutive days resulted in an efficacy of 83.35%, which increased to 96.28% by seven days post-treatment. Safety evaluations revealed this regimen induced transient oxidative stress and mild, reversible histopathological alterations in the liver and gills. Biochemical and histological markers indicated a recovery trend, approaching baseline levels by 15 days post-treatment. These findings suggested that oral fenbendazole is an effective and relatively safe anthelmintic treatment against G. kobayashii in goldfish. This study underscores the potential of drug repurposing as an effective strategy for developing novel anthelmintic agents in aquaculture.

Excretory-secretory products from the parasite Schistocephalus solidus enhance viability and function of threespine stickleback splenocytes

2025-06-19

Alexandra Collias , Annie Cary , Natalie C. Steinel | bioRxiv (Cold Spring Harbor Laboratory)

Abstract Helminths can modulate the immune systems of their hosts through the release of soluble molecules known as excretory-secretory products (ESPs). To better understand the extent and mechanisms behind helminth-mediated … Abstract Helminths can modulate the immune systems of their hosts through the release of soluble molecules known as excretory-secretory products (ESPs). To better understand the extent and mechanisms behind helminth-mediated immunosuppression, we used an emerging model of host-parasite interactions, threespine stickleback, Gasterosteus aculeatus , and its tapeworm parasite Schistocephalus solidus . We examined the impacts of exposure to ESPs of S. solidus (SsESPs) originating from four Canadian lakes on the viability and function of threespine stickleback splenocytes. We found that 24 hours of exposure to low concentrations of SsESPs significantly increased overall splenocyte viability with the greatest impact on the lymphocyte population. While SsESP exposure did not alter baseline splenocyte respiratory burst activity, SsESP-treated splenic cultures demonstrated significant increases in ROS production in response to phorbol 12-myristate 13-acetate (PMA) stimulation, suggesting that SsESPs may lower the threshold for activation of the respiratory burst. These results in splenocytes contrast with previous studies demonstrating that SsESPs suppress head kidney leukocytes (HKL) viability and function, suggest that S. solidus -derived excretory secretory products may have cell-or tissue-specific immunomodulatory effects, and highlight the importance of studying host-parasite interactions across diverse immune tissues.

NEW RECORD OF TWO EURYHALIOTREMA KRITSKY & BOEGER, 2002 SPECIES (MONOGENOIDEA, DACTYLOGYRIDAE) FROM LUTJANID FISHES FROM MARINE COAST OFF IRAQ

2025-06-19

Ali Adnan Al-Darwesh , Atheer H. Ali , Israa Abd Al-Ameer | Bulletin of The Iraq Natural History Museum

The snappers (Lutjanid fish) are an important food source for the Iraqi people. Three species of lutjanid fishes- the Blackspot snapper Lutjanus ehrenbergii (Peters, 1869), Dory snapper L. fulviflamma (Forsskål, … The snappers (Lutjanid fish) are an important food source for the Iraqi people. Three species of lutjanid fishes- the Blackspot snapper Lutjanus ehrenbergii (Peters, 1869), Dory snapper L. fulviflamma (Forsskål, 1775) and L. indicus Allen, White & Erdmann, 2013 were caught from Iraqi marine waters in the Arabian Gulf during 2024. The Blackspot snapper L. ehrenbergii and the Dory snapper L. fulviflamma were found to be infested with both Euryhaliotrema adelpha Kritsky & Justine in Kritsky, 2012 (reported here as a new host) and E. spirotubiforum (Zhang, 2001) Wu, Zhu, Xie & Li, 2006. L. indicus was infested only with E. spirotubiforum which is reported here for the first time from this host species and this geographical area (the Arabian Gulf). Illustrations of whole- mount specimens are given for E. adelpha for the first time. This investigation represents the first report of monogenoids from lutjanid fishes in Iraq.

Особенности формирования гельминтофауны рыб нижнего течения реки Раздан (Армения) в условиях антропогенного пресса

2025-06-19

R. L. Hovhannisyan , M. Y. Rukhkyan , Bardukh Gabrielyan | Ecosystem Transformation

Приведены данные исследований видового состава гельминтофауны и степени инвазированности рыб нижнего течения реки Раздан. Исследования проводились в 2019–2020 гг., были обследованы 454 особи 15 видов рыб. Обнаруженная гельминтофауна характеризовалась невысоким … Приведены данные исследований видового состава гельминтофауны и степени инвазированности рыб нижнего течения реки Раздан. Исследования проводились в 2019–2020 гг., были обследованы 454 особи 15 видов рыб. Обнаруженная гельминтофауна характеризовалась невысоким видовым разнообразием, в результате выявлено 5 видов гельминтов: 1 вид Monogenea, 1 вид Trematoda, 2 вида Cestoda и 1 вид Nematoda. Общая инвазированность рыб гельминтами составила 34.1%. Обнаруженные гельминты были локализованы в основном в полости тела, кишечнике, хрусталиках глаз и на жабрах рыб. Наибольшее количество видов гельминтов отмечалось у храмуль и карасей. Практически на всех исследуемых участках нижнего течения реки наиболее распространенными из обнаруженных видов гельминтов были плероцеркоиды цестоды Ligula intestinalis (L., 1758) и метацеркарии трематод Diplostomum sp. Nordmann, 1832. Data from studies of the species composition of the fish helminth fauna and the degree of fish infection in the lower reaches of the Hrazdan River are presented. The studies were conducted in 2019–2020; 454 individuals of 15 fish species were examined. The detected helminth fauna was characterized by low species diversity, as a result, 5 species of helminths were identified: 1 species of Monogenea, 1 species of Trematoda, 2 species of Cestoda and 1 species of Nematoda. The total infection of fish by helminths was 34.1%. The detected helminths were localized mainly in the body cavity, intestine, eye lenses and on the gills of fish. The largest number of helminth species was noted in khramicarps and crucian carps. In almost all the studied areas of the lower reaches of the river, the most common of the detected species of helminths were plerocercoids of the cestode Ligula intestinalis (L., 1758) and metacercariae of the trematode Diplostomum sp. Nordmann, 1832.

Lethal, disseminated infection with an oomycete ( Halioticida noduliformans ) in captive, deep-sea isopods ( Bathynomus giganteus and Bathynomus doederleinii ) in California

2025-06-18

Elise E. B. LaDouceur , Megan Olhasso , Michael J. Murray +3 more | Veterinary Pathology

There are no previous publications on diseases of Japanese isopods ( Bathynomus doederleinii ) or giant deep-sea isopods ( Bathynomus giganteus ). Halioticida noduliformans is a pathogenic oomycete that infects … There are no previous publications on diseases of Japanese isopods ( Bathynomus doederleinii ) or giant deep-sea isopods ( Bathynomus giganteus ). Halioticida noduliformans is a pathogenic oomycete that infects external tissues of abalone, mantis shrimp, and European lobsters, and has not been previously reported in isopods. The purpose of this study is to describe the clinical presentation, gross findings, and histologic lesions caused by H. noduliformans in B. doederleinii and B. giganteus kept in a public aquarium in California. Oomycetes caused inflammation and necrosis in the body wall, gills, hepatopancreas, eyes, and gut. Our study demonstrates that this pathogen occurs in a previously unreported geographic location and in previously unpublished hosts. H. noduliformans infected both external and internal viscera, the latter of which has not been previously reported in any host species. H. noduliformans has variable pathogenicity depending on the host species and was considered the cause of death in these isopods.

Evaluation of benzocaine and eugenol as anesthetics and antiparasitic agents in a freshwater fish model

2025-06-18

Clara Vercellini , A C Carranza-Martín , Martín Miguel Montes +1 more | Aquaculture International

Zoonotic and ecological implications of parasites in a popular edible fish, Saurida tumbil (Family Synodontidae): Insights from review and original research

2025-06-18

Shokoofeh Shamsi , Javad Khedri , Hassan Borji | International Journal of Food Microbiology

Saurida tumbil, is a commercially valuable fish which is found in 36 countries and islands across Africa, Asia, and Oceania. It serves as a key food resource for many coastal … Saurida tumbil, is a commercially valuable fish which is found in 36 countries and islands across Africa, Asia, and Oceania. It serves as a key food resource for many coastal communities, making the identification and assessment of its parasitic biota important for food safety and ecological monitoring. In this study, 140 specimens of S. tumbil, obtained from local fish markets were examined for foodborne parasites using both morphological and molecular approaches. A total of 123 nematodes, all alive, were collected from 33 infected fish. We also conducted an extensive review of parasites previously associated with this fish species. Our findings based on the examination of fish and the literature review reveal that S. tumbil hosts a diverse range of parasites, such as protozoans, nematodes, and tapeworms, several of which present potential zoonotic risks. Key discoveries include the first identification of Anisakis larval type III as A. brevispiculata, as well as evidence that Anisakis larval type I consists of two genetically distinct species, both labelled as A. typica in GenBank despite exhibiting greater genetic divergence. Anisakis nematodes are a known seafood borne parasites. Additionally in the literature, another parasite, trypanorhynch tapeworm larvae, were commonly found in this fish. Although human infections with trypanorhynch larvae are rare, similar to anisakids they can cause allergic reactions and reduce the marketability of fish due to consumer aversion caused by presence of parasites in fish flesh. Our results also highlight the challenges posed by mislabelled sequences in GenBank, which complicate the accurate identification of parasite larvae. These inaccuracies impede species-level identification, obscure the true diversity and zoonotic potential of these parasites, and ultimately hinder effective monitoring and public health responses. Our results contribute to a better understanding of Saurida tumbil's role as a host for diverse parasite species with both ecological and zoonotic significance.

An investigation on fingerling grass carp Ctenopharyngodos idella ectoparasites with the first occurrence of Tylodelphys clavata as a new locality record in northern Iran

2025-06-18

Mehrdad Asgharnia , Javad Daghigh Roohi , Seyed fakhraddin Mirhashemi Nasab +1 more | Brazilian Journal of Aquatic Science and Technology

Aquaculture in Iran has been developing quickly in recent years and includes the introduction of various new species such as Chinese carp (Ctenopharyngodon idella, Hypophthalmichthys molitrix, and Hypophthalmichthys nobilis), rainbow … Aquaculture in Iran has been developing quickly in recent years and includes the introduction of various new species such as Chinese carp (Ctenopharyngodon idella, Hypophthalmichthys molitrix, and Hypophthalmichthys nobilis), rainbow trout (Oncorhynchus mykiss) and stocks of common carp (Cyprinus carpio). The main aim of this study was to determine the external parasitic fauna of grass carp Ctenopharyngodon idella, from aquaculture facilities in northern Iran, alongside their prevalence level, intensity, and abundance. A total of 35 fingerlings of Grass carp with an average length of 10cm and an average weight of 7g was caught from a fish farm in Guilan province, northern Iran, and transported alive to the Parasitology laboratory in the autumn of the year 2019. Common procedures of Parasitology were performed for fish sampling. All specimens (prevalence of 100%) were infected with different parasite groups. Diplostomum spathaceum and Dactylogyrus lamellatus were respectively recovered from the eyes and gills of all fish, with a mean intensity of 14.8 and 8.6 each. Also, Ichthyophthirius multifiliis was observed at the highest level of 100% in the skin and gills, followed by Gyrodactylus sp. and Tylodelphys clavata were respectively detected in the skin and eyes of grass carp with the lowest prevalence value of 20% and intensity of 1, in common each. The record of Tylodelphis clavata in grass carp in the present study is considered the first report on the northern Iranian aquaculture system.

Elucidation of the life cycle of the trematode Curtuteria arguinae (Digenea: Himasthlidae), using environmental DNA detection methods

2025-06-18

Leslie Stout , Guillemine Daffe , Aurélie Chambouvet +3 more | Parasitology

‘I walk a lonely road’: solitary seals have fewer lice

2025-06-18

Florencia Soto , Javier Negrete , Alejandro D. Buren +1 more | Antarctic Science

Abstract Leopard seals ( Hydrurga leptonyx ) lead solitary lives, mainly associated with sea ice, and they are parasitized by the sucking louse Antarctophthirus ogmorhini , one of the few … Abstract Leopard seals ( Hydrurga leptonyx ) lead solitary lives, mainly associated with sea ice, and they are parasitized by the sucking louse Antarctophthirus ogmorhini , one of the few known marine insects and probably the only group adapted to survive in deep-ocean environments. A challenge for seal lice is that their eggs do not survive underwater, requiring them to complete their life cycle during the host’s reproductive or moulting season. We investigated the infestation parameters of A. ogmorhini in leopard seals on the Danco Coast, Antarctic Peninsula, estimating prevalence and mean abundance, comparing by sex, age class and interannual variability and determining the relationship between these parameters and the body condition of the seals. Over four field seasons (2014, 2015, 2019 and 2020), we collected data from 50 seals: 12 females and 38 males, including 47 adults and 3 juveniles. The overall prevalence (14%) was the lowest recorded for an Antarctic seal, with higher rates in juveniles (33.3%) than adults (12.8%) and in males (15.8%) compared with females (8.3%). Generalized linear models analysis, considering body condition and interannual variability, did not reveal a strong correlation between body condition and lice infestation. Although no strong correlation was found, there is some indication that seals in poorer condition may be more heavily infested.

Ficha de Loxosceles troglobia

2025-06-17

Maysa Fernanda Villela Rezende Souza , Antônio D. Brescovit , Marconi Souza‐Silva +4 more | Datasets - Sistema SALVE - ICMBio

Beyond Motility: A Multiparametric Fitness Assay Framework to Evaluate Anthelmintics in Nippostrongylus brasiliensis

2025-06-17

Kyle Anesko , Sarah Midou , Rebecca Ruggiero-Ruff +5 more | bioRxiv (Cold Spring Harbor Laboratory)

Abstract We adapted a multiparametric fitness assay panel—including ATP quantification, larval growth, pigmentation, and cuticle permeability—to assess Nippostrongylus brasiliensis viability in vitro . To validate this system, we benchmarked two … Abstract We adapted a multiparametric fitness assay panel—including ATP quantification, larval growth, pigmentation, and cuticle permeability—to assess Nippostrongylus brasiliensis viability in vitro . To validate this system, we benchmarked two known anthelmintics with distinct modes of action: quinidine, a heme detoxification disruptor, and pyrantel pamoate, a neuromuscular antagonist. We then applied this framework to NCR247, a plant-derived heme-sequestering peptide with proposed antiparasitic activity. While the assay panel sensitively detected physiological disruption by known anthelmintics, NCR247 did not significantly impair parasite fitness across any tested parameter. These findings highlight the utility of integrated viability assays and suggest further in vivo or delivery-optimized studies may be necessary to evaluate NCR247 efficacy.

A Systematic Revision of Kroyeria (Copepoda: Siphonostomatoida): Five New Species, 11 Redescriptions, and a Morphological Phylogenetic Analysis of the Genus

2025-06-17

Gregory B. Deets , Geoffrey A. Boxshall , James P. Bernot | Journal of Parasitology

This study focuses on the taxonomy and systematics of Kroyeria, a genus of ectoparasitic copepods found on the gills of sharks. Members of the genus Kroyeria exhibit species-specific appendage ornamentation, … This study focuses on the taxonomy and systematics of Kroyeria, a genus of ectoparasitic copepods found on the gills of sharks. Members of the genus Kroyeria exhibit species-specific appendage ornamentation, including denticles, membranes, and setules, in addition to the setae and spines typical of most copepods. The taxonomy and systematics of Kroyeria have been hampered by the lack of observation of these fine morphological details. This study is a systematic revision of the genus in which 11 species of Kroyeria are redescribed, 6 species are synonymized, and 5 new species are described: Kroyeria branchiocetes n. sp. from Carcharhinus amblyrhynchos from the Red Sea, Kroyeria cresseyi n. sp. from Triakis semifasciata from off California, Kroyeria decepta n. sp. from Carcharhinus obscurus from the Pacific Ocean off Mexico, Kroyeria procerobscena n. sp. from Carcharhinus leucas from off Madagascar, and Kroyeria rhophemophaga n. sp. from Galeorhinus galeus from off California. With this work, Kroyeria now comprises 20 valid species. The 16 species of Kroyeria that were examined in this study were scored for 44 morphological characters, which were used for a phylogenetic analysis of the genus.

Overlooked Parasite Diversity in Staurozoa: Two Species of Lepocreadiidae (Trematoda: Digenea) Parasitic in Haliclystus tenuis

2025-06-17

K. Tsutsui , Keiichi Kakui | ZOOLOGICAL SCIENCE

A chromosome-level genome assembly of the Bullacta exarata (Cephalaspidea: Haminoeidae)

2025-06-16

Yongchao Zhao , Yong Chi , Ann Chen Wu +6 more | Scientific Data

The mudsnail, Bullacta exarata, is an important marine food mollusk for both economic and aquaculture purposes. However, the scarcity of genomic information has hindered genetic research and breeding efforts. To … The mudsnail, Bullacta exarata, is an important marine food mollusk for both economic and aquaculture purposes. However, the scarcity of genomic information has hindered genetic research and breeding efforts. To address this gap, we developed a chromosome-level genome assembly utilizing short reads, HiFi long reads, and Hi-C sequencing data. The final assembly measures 836.77 Mb, with scaffold N50 and contig N50 values of 48.61 Mb and 1.00 Mb, respectively. Using Hi-C technology, 815.25 Mb (97.43%) of the contigs were anchored and arranged into 18 pseudochromosomes. A total of 358.66 Mb was identified as repeat elements, representing 42.86% of the genome. Furthermore, we predicted 85,914 non-coding RNAs and 17,996 protein-coding genes, with 93.48% of the protein-coding genes annotated. The BUSCO analysis indicated that the completeness of the genome assembly and annotation is 94.55% and 96.65%, respectively. Phylogenetic analysis clarified the evolutionary relationships between B. exarata and representative species in gastropoda. This high-quality reference genome for B. exarata serves as a valuable resource for aquaculture, fisheries, and ecological research.

Seasonal prevalence on the Parasitism of Istiophorus platypterus (Shaw, 1792) by Pennella sp. (Copepoda: Pennellidae) from the Tamil Nadu Coastal waters, India

2025-06-16

Vasanthan Koothan , Mukesh Murukesan , A Gopalakrishnan +2 more | Species

The diversity of Khawia tapeworms (Cestoda: Caryophyllidea) of barbels (Cyprinidae: Barbinae) in the western Palearctic: the existence of vicariant lineages and the description of a new species from the Iberian Peninsula

2025-06-16

Kamila Koutná , Michal Benovics , Tomáš Scholz | Parasitology

Diversity and Host Associations of Parasitic Isopods (Isopoda: Cymothoidae) from Marine Fishes of southeast coast of India

2025-06-13

V. Singaravel | Research Square (Research Square)

<title>Abstract</title> A total of 15 species of parasitic isopods were identified belonging to six genera <italic>viz.,</italic> <italic>Cymothoa eremita</italic> Brunnich, 1783<italic> </italic>Host: <italic>Parastromateus</italic> <italic>niger</italic> (Bloch, 1795), <italic>C. indica</italic>Schioedte and Meinert, 1884 … <title>Abstract</title> A total of 15 species of parasitic isopods were identified belonging to six genera <italic>viz.,</italic> <italic>Cymothoa eremita</italic> Brunnich, 1783<italic> </italic>Host: <italic>Parastromateus</italic> <italic>niger</italic> (Bloch, 1795), <italic>C. indica</italic>Schioedte and Meinert, 1884 Host: <italic>Ambassis ambassis</italic> (Lacepède, 1802), <italic>Joryma brachysoma </italic>(Pillai, 1964)<italic> </italic>Host: <italic>Ilisha melastoma</italic> (Bloch & Schneider, 1801),<italic> J. hilsae </italic>Rameshkumar, Ravichandran & Jean-Paul Trilles, 2011 Host: <italic>Pellona ditchela</italic> Valenciennes, 1847, <italic>Mothocya plagulophora</italic> (Haller, 1880) Host: <italic>Hemiramphus far </italic>(Forsskål, 1775), <italic>M. renardi</italic> (Bleeker, 1857) Host: <italic>Strongylura leiura </italic>(Bleeker, 1850), <italic>M. collettei </italic>Bruce, 1986<italic> </italic>Host: <italic>Tylosurus crocodilus crocodilus </italic>(Péron & Lesueur, 1821), <italic>M. karobran</italic>Bruce, 1986 Host: <italic>T. crocodilus crocodilus </italic>(Péron & Lesueur, 1821), <italic>Nerocila phaiopleura</italic>Bleeker, 1857 Hosts: <italic>Sardinella longiceps </italic>Valenciennes, 1847<italic>, Chirocentrus nudus</italic> Swainson, 1839 and <italic>Rastrelliger kanagurta </italic>(Cuvier, 1816), <italic>N. sundaica</italic> Bleeker, 1857<italic> </italic>Host: <italic>Sardinella fimbriata </italic>(Valenciennes, 1847), <italic>N. sigani</italic> Bowman and Tareen, 1983 Host: <italic>Siganus canaliculatus </italic>(Park, 1797)<italic>, N. loveni</italic> (Bovallius, 1887) Host: <italic>Opisthopterus tardoore </italic>(Cuvier, 1829), <italic>Norileca indica</italic> (H. Milne Edwards, 1840) Host: <italic>Selar crumenophthalmus</italic> (Bloch, 1793), <italic>N. triangulata </italic>(Richardson, 1910) Host: <italic>R. kanagurta </italic>(Cuvier, 1816), <italic>Ryukyua circularis</italic> (Pillai, 1954) Host: <italic>Amblygaster sirm</italic>(Walbaum, 1792). Most of the parasitic isopods are not the host specific. However, they are specific to infestation locations (gill chamber, buccal cavity and body). Pathological effects on the host species also differ according to the site of attachment.

Morphological description and molecular characterisation of Opegaster mezcal sp. n. (Trematoda: Opecoelidae) from the Mexican Tropical Pacific

2025-06-12

Rodrigo Iván Santillán-Pérez , Martìn García-Varela , Rogelio Aguilar‐Aguilar | Folia Parasitologica

Ficha de Phenacogaster naevata

2025-06-12

André Luiz Netto Ferreira , Bruno Francelino de Melo , Fernando Rogerio de Carvalho +7 more | Datasets - Sistema SALVE - ICMBio

Fish, Snails, and Parasites of Laguna Cartagena, Puerto Rico Show Rapid Change and Dominance of Non-Native Species

2025-06-12

Gabriel M. Torres-Nieves , Diana M. B. Perales-Macedo , Sean A. Locke | Caribbean Journal of Science

Systematic infection of the foot of the mediterranean mussel (Mytilus galloprovincialis) by a trematode parasite (Digenea: Monorchiidae) in the farms of Tyrrhenum and Adriatic Sea (Italy)

2025-06-11

Francesca Carella | Aquaculture

Genetic diversity and population structure of Prosimulium rachiliense Djafarov, 1954 (Diptera: Simuliidae) in Türkiye

2025-06-11

Davut Ümit Şirin , Büşra Aslan Kocatürk | Acta Tropica

Fish Parasites, Host Parasite interaction, Economic Burden, Zoonotic Risks, and Sustainable Control Strategies with Special Refence to Pakistan

2025-06-10

Inayat Ullah , Chand Bibi , Abdul Baset +2 more | Indus journal of bioscience research.

Fish parasites represents, growing threat to global aquaculture, wild fisheries and public health due to their complex life cycles, high pathogenicity, and increasing zoonotic potential. This review highlights the host-parasite … Fish parasites represents, growing threat to global aquaculture, wild fisheries and public health due to their complex life cycles, high pathogenicity, and increasing zoonotic potential. This review highlights the host-parasite interactions, economic impact, and diagnostic challenges of the main groups of fish parasites, such as protozoans, trematodes, cestodes, nematodes, crustacean ectoparasites, and myxozoans. This paper also highlights the role of climate change in altering parasites distribution and accelerating diseases emergence, particularly in aquaculture system under environmental stress. Regional problems, particularly in Pakistan, are highlighted to support the call for enhanced surveillance, diagnostics, and control measures in developing nations. Emergency treatment methods and integrated management practice are reviewed, with a focus on sustainable alternatives to traditional chemotherapeutants. By synthesizing current research and identifying knowledge gaps, this paper aims to assist aquaculture professionals in formulating adaptive measures in parasite management amidst ecological and societal transformations.