Fish Parasitology Research Articles

Unlocking the Biological Enigma: Influence of Host Length and Infection Site on Parasite Abundance in Ompok bimaculatus.

The influence of two key factors, host length and infection site, on the host-parasite interaction in Ompok bimaculatus (Butter catfish) from Mukutmanipur Dam Lake, were investigated. Present study involved 192 specimens of Ompok bimaculatus with varying body lengths, subjected to diverse statistical analyses. One-way analysis of variance (ANOVA) was performed for the parasite numbers for three groups (cestode, nematode and trematode). Subsequently, we conducted one-way permutational multivariate analysis of variance (PERMANOVA) followed by pairwise test to assess parasite numbers across three body sites (intestine, mesentery, and bodycavity), employing the Bray-Curtis index. Additionally, Principal Coordinate Analysis (PCoA) for the same dataset was performed using the same index. Linear regression analysis was performed for the fish length-cestode number, fish length-nematode number, fish length-trematode number and fish length-total parasite number. One-way ANOVA revealed no significant differences in parasite numbers among the three endo-helminth groups (cestode, nematode, and trematode). The results of PERMANOVA revealed significant differences in parasite numbers across the three body sites of the host fishes (groups) (F = 9.41, p = 0.0001). Pairwise tests further demonstrated significant differences between the intestine-mesentery, intestine-body-cavity, and mesentery-body-cavity. Additionally, Principal Coordinate Analysis (PCoA) unveiled a significant relationship between infection site and parasite number. However, linear regression analysis examining the relationship between fish length and parasite abundance indicated no significant associations. Through a detailed exploration of the statistical analyses, we provide insights into the host-parasite interaction, elucidating both established knowledge and novel findings in fish parasitology.

Endohelminth diversity in the invasive Clarias gariepinus (Burchell, 1822) from two freshwater lakes: Naivasha and Ol'Bolossat, Kenya.

Fish parasitology contributes to our understanding of the potential risks posed by diverse groups of parasitic organisms on fish stocks in either wild and culture systems. This study was conducted in May 2023 and aimed at assessing the diversity of endohelminths in the invasive North African catfish Clarias gariepinus (Burchell, 1822) obtained from two freshwater lakes, Naivasha and Ol'Bolossat, in Kenya. Parasitological examination of 66 and 35 fish samples collected from the two lakes respectively was achieved using light and scanning electron microscopy methods. Results revealed endohelminth diversity broadly classified as four digeneans, two nematodes, and one cestode. Seven taxa of endohelminths were found in C. gariepinus samples, but only four of these taxa could be identified up to the species level. Six of the taxa (Diplostomum sp., Tylodelphys mashonense, Plagiorchioidea sp., Paracamallanus cyathopharynx, Contracaecum sp., and Tetracampos ciliotheca) were common in samples from the two lakes. Glossidium pedatum only occurred in samples from Lake Ol'Bolossat. Parasite prevalence ranged from 8.6 (T. mashonense) to 100% (Diplostomum sp., T. ciliotheca, and Contracaecum sp.) and mean intensity from 1.4 (T. mashonense) to 16.9 (Diplostomum sp.). The diversity and richness indices were comparatively higher in fish samples from Lake Ol'Bolossat and attributed to the occurrence of G. pedatum in the Ol'Bolossat. However, parasitic infestation of fish samples from the two lakes depicted close similarity, both in diversity and prevalence. These findings form an important baseline data for further follow-up studies, and they suggest the need for further molecular analyses to fully describe three of the taxa only identified up to the genus level.

Fish ectoparasite detection, collection and curation.

Fish parasitology is a dynamic and internationally important discipline with numerous biological, ecological and practical applications. We reviewed optimal fish and parasite sampling methods for key ectoparasite phyla (i.e. Ciliophora, Platyhelminthes, Annelida and Arthropoda) as well as recent advances in molecular detection of ectoparasites in aquatic environments. Ideally, fish capture and anaesthesia as well as parasite recovery methods should be validated to eliminate potential sampling bias and inaccuracy in determining ectoparasite population parameters. There are considerable advantages to working with fresh samples and live parasites, when combined with appropriate fixation methods, as sampling using dead or decaying materials can lead to rapid decomposition of soft-bodied parasites and subsequent challenges for identification. Sampling methods differ between target phyla, and sometimes genera, with optimum techniques largely associated with identification of parasite microhabitat and the method of attachment. International advances in fish parasitology can be achieved through the accession of whole specimens and/or molecular voucher specimens (i.e. hologenophores) in curated collections for further study. This approach is now critical for data quality because of the increased application of environmental DNA (eDNA) for the detection and surveillance of parasites in aquatic environments where the whole organism may be unavailable. Optimal fish parasite sampling methods are emphasised to aid repeatability and reliability of parasitological studies that require accurate biodiversity and impact assessments, as well as precise surveillance and diagnostics.

A century of parasitology in fisheries and aquaculture.

Fish parasitological research associated with fisheries and aquaculture has expanded remarkably over the past century. The application of parasites as biological tags has been one of the fields in which fish parasitology has generated new insight into fish migration and stock assessments worldwide. It is a well-established discipline whose methodological issues are regularly reviewed and updated. Therefore, no concepts or case-studies will be repeated here; instead, we summarize some of the main recent findings and achievements of this methodology. These include the extension of its use in hosts other than bony fishes; the improvements in the selection of parasite tags; the recognition of the host traits affecting the use of parasite tags; and the increasingly recognized need for integrative, multidisciplinary studies combining parasites with classical methods and modern techniques, such as otolith microchemistry and genetics. Archaeological evidence points to the existence of parasitic problems associated with aquaculture activities more than a thousand years ago. However, the main surge of research within aquaculture parasitology occurred with the impressive development of aquaculture over the past century. Protozoan and metazoan parasites, causing disease in domesticated fish in confined environments, have attracted the interest of parasitologists and, due to their economic importance, funding was made available for basic and applied research. This has resulted in a profusion of basic knowledge about parasite biology, physiology, parasite-host interactions, life cycles and biochemistry. Due to the need for effective control methods, various solutions targeting host-parasite interactions (immune responses and host finding), genetics and pharmacological aspects have been in focus.

ICOPA 2022: living with parasites, collaborating globally, and breaking a glass ceiling

ICOPA 2022: living with parasites, collaborating globally, and breaking a glass ceiling

Distribution of Anisakidae Family Infected Marine Fish in Indonesia

Background: Family of Anisakidae is one of the zoonotic helminth parasitics. The distribution of the family Anisakidae is extensive. It needs to be known because the diversity of parasites can provide information about the distribution area and impact of the parasites of the family Anisakidae in Indonesia. This review article summarises the distribution of parasites from the family Anisakidae that infects marine fish and the factors that influence Indonesia. Methods: This research is qualitative research through literature study as the main object. The data from the literature study results are presented in tables and figures then explained descriptively. Results: The distribution of Anisakidae in Indonesia is found in four genera, namely the genus Anisakis, Pseudoterranova, Terranova and Contracaecum, which are mostly found from the carnivorous marine fish of the family Balistidae, Carangidae, Epinephelidae, Lutjanidae, Priacanthidae, and Scombridae Conclusions: Four genera of endoparasitic worms from the Anisakidae family were reported to infect Indonesian marine fish, including Anisakis, Pseudoterranova, Terranova and Contracaecum. Temperature, salinity, hosts' presence, and anthropogenic factors are biotic and abiotic factors that can affect the distribution of Anisakidae. The information on this literature study results is hoped to be used as the basis for developing research in fish parasitology in particular and increasing public awareness of fish processing in general.

Fisheries research of the Pyasina river basin

At the end of April 2020, the largest man — made disaster in the Russian Arctic occurred-a diesel fuel spill in Norilsk. Oil products on the Ambarnaya river got to the lake. Pyasino (source of the river of the same name). To determine the extent of damage to the aquatic ecosystem of the Pyasina basin, it is necessary to know the nature and direction of previous research in the fisheries field. The aim of the work is to analyze the available open source publications in the field of fisheries research in the Pyasina basin. The history of ichthyological and hydrobiological studies of the Pyasina river basin (a large watercourse on the Taimyr Peninsula) is considered. Information is provided that the basin of this river is poorly studied in terms of fisheries due to its location beyond the Arctic circle. The chronology of fisheries research from the Foundation of the Yenisei ichthyological laboratory (Krasnoyarsk) in 1908 to 2020 is given. It is noted that the greatest interest in studying the basin of this river is shown in connection with the development of the Norilsk mining and metallurgical combine and the organization of the Federal state budgetary institution «United Directorate of Taimyr reserves». The role of individual scientific organizations in the study of water ecosystems of the Pyasina river basin is shown. The most significant contribution to the fisheries survey of the river basin was made by the Siberian scientific fisheries station (now the Krasnoyarsk branch of the all-Russian research Institute of fisheries and Oceanography), MSU, TSU. The publications of employees of these organizations contain materials on the study of phytoplankton and zooplankton, zoobenthos, their production characteristics, the biology of a number of species, the Stingray of larvae, features of the development of semi-passable ichthyofauna, materials on the genetic features of individual populations of whitefish, biological and morphological features of whitefish and char fauna, fish Parasitology, the content of polyunsaturated fatty acids, and others. Information is provided on the number of zooplankton species and forms, including 28 forms. It is shown that the composition of the ichthyofauna of the river basin to date, 38 species of fish are known.

A Review of the Parasites of Deep-Water Fishes from Macaronesian Islands, North-East Atlantic Ocean

The deep-water fish fauna of Macaronesian islands is currently estimated at a total of 1029 different fish species, but records of both ecto- and endoparasites are from only about 30 of those species. This fact presents an exciting field of research for scientists interested in fish parasitology, by exploring the structure of parasite communities and their connections with ecological and oceanographic variables. Research on the effect of climatic changes on the parasite faunas, on the occurrence of fish parasites in man and its impact on human health, has not been carried out to date. The present review aims to collate our present knowledge about the parasites of deep-water fishes of Macaronesia, and to suggest directions for future research on the parasites of fishes from the deepwater realm. A checklist of the parasites infecting the deep-water fishes from this region is included.

First record of Azygia robusta (Odhner, 1911) (Trematoda: Digenea: Azygiidae) in brown trout (Salmo trutta) in the VRBAS River

Abstract The investigation of fish parasites in Bosnia and Herzegovina in recent years became significant, and therefore new records of parasitic trematodes and their hosts are important for better understanding of fish parasitology and pathology. In this study 41 parasitic specimens were collected and the basic taxonomical characters were measured (body length and width, diameter of oral and ventral sucker, length and width of pharynx, ovary length and width, testes length and width and eggs length and width). After the sampling of the parasites, they were collected and conserved in 70% ethanol. After that procedure the aforementioned characters were measured using Digimizer Image Analyzer Version 4.1. After all measurements, the trematode parasite Azygia robusta was confirmed for the first time on brown trout Salmo trutta. This first record was found in the Vrbas River near Banja Luka, Bosnia and Herzegovina (Sava River Basin). Former records of this parasite in Europe were observed on other salmonid fish species, as huchen Hucho hucho. This new record should be very important part of data of fish parasitology in Bosnia and Herzegovina.

Helminth parasites of South American fishes: current status and characterization as a model for studies of biodiversity.

The South American subcontinent supports one of the world's most diverse and commercially very important ichthyofauna. In this context, the study of South American fish parasites is of increased relevance in understanding their key roles in ecosystems, regulating the abundance or density of host populations, stabilizing food webs and structuring host communities. It is hard to estimate the number of fish parasites in South America. The number of fish species studied for parasites is still low (less than 10%), although the total number of host-parasite associations (HPAs) found in the present study was 3971. Monogeneans, with 835 species (1123 HPAs, 28.5%), and trematodes, with 662 species (1127 HPAs, 30.9%), are the more diverse groups. Data gathered from the literature are useful to roughly estimate species richness of helminths from South American fish, even though there are some associated problems: the reliability of information depends on accurate species identification; the lack of knowledge about life cycles; the increasing number of discoveries of cryptic species and the geographically biased number of studies. Therefore, the closest true estimations of species diversity and distribution will rely on further studies combining both molecular and morphological approaches with ecological data such as host specificity, geographical distribution and life-cycle data. Research on biodiversity of fish parasites in South America is influenced by problems such as funding, taxonomic impediments and dispersion of research groups. Increasing collaboration, interchange and research networks in the context of globalization will enable a promising future for fish parasitology in South America.

First record of sea lice Lepeophtheirus curtus (Copepoda, Caligidae) in sea-farmed Epinephelus marginatus (Serranidae) in Brazil.

(With 1 figure)The family Caligidae, mainly Caligus and Lepeophtheirus species are widespread sea lice copepods that parasitize body surface, cavity of the mouth, the gills, and the operculum of teleosts and elasmobranchs ( Ho et al., 2001 ). These parasites erode fishes epithelium leading secondary bacterial infections (Sanches et al., 2012). The sea lice of the family Caligidae are one of the most major health pathogens for farmed fish. In the Northern Hemisphere the salmon louse Lepeophtheirus salmonis (Kroyer, 1838) alone is responsible for commercial losses in excess of € 180 million in salmonid aquaculture ( Costello, 2009 ).The dusky grouper ( Epinephelus marginatus ) (Lowe, 1834) is a Serranidae protogynous hermaphrodite species with great ecological importance. It is being commercially cultured because the high market demand has led to indiscriminate fishing resulting in the depletion of the natural stocks to an alarming level ( Sanches et al., 2009 ). Despite the considerable progress in fish parasitology in recent decades, there are still major gaps in knowledge of taxonomy, biology, epizootiology and parasites control ( Roumbedakis et al., 2013 ). This study record the first occurrence of Lepeophtheirus curtus in dusky grouper farmed in Brazil.Specimens of copepods were collected from twelve farmed Ephinephelus marginatus (wet weight 6.2 ± 0.2 kg) that were kept in concrete tanks, capacity 80 m

Parasites as Health Indicators in Wild Fish Populations

More often than not, when we are watching TV or reading the news, we see these images of piles of fish agonizing and dying on the shores of numerous rivers and lakes, and we can’t help to wonder what is happening with the aquatic ecosystems worldwide. Can we drink that water and eat those fish anymore? We also think. In the last few decades, since the first studies on fish parasitology until now, the scientific community has made great advances on this subject and can provide us with some useful information regarding management and prevention. Here, we present you another opinion, based on the conclusions of some researchers, about a new role for the fish parasite communities, this time as helpers and indicators of the health status of the wild fish populations and the whole aquatic ecosystem.

New occurrence of parasitic isopod Argathona sp. (Stebbing, 1905) from Epinephelus undulosus in the Tuticorin coast, Gulf of Mannar region.

In the present study of Epinephelus undulosus captured in gillnets from the inshore waters of Tuticorin, Gulf of Mannar region during December 2014. The present findings represent the first occurrence of Argathona sp. and here in reported. The materials examined were deposited at the Kamaraj College, Marine Biological Research Laboratory, Tuticorin, India. The parasitological indexes were calculated. The site of attachment of the parasites on their hosts was also observed. Host-parasite relationships are considered and these parasites can cause the damage in gill, eye and internal organ including swim bladder. Marine fish parasitology is a rapidly developing field of aquatic science.

A brief history of freshwater fish parasitology in southern Africa

The paper presents an overview of the history of aquatic parasitology of freshwater fish in southern Africa. Aquatic parasitology has become a very popular field of specialisation in South Africa and is currently practised by a number of individual research groups at different universities. So far most research deals with parasites of wild fish rather than pathogens of aquaculture. It is written as a narrative and summarises the aquatic parasitology research mostly on fish parasites carried out at the universities of Cape Town, Free State, Johannesburg, Limpopo, Pretoria, North West and Sefako Makgatho Health Sciences. It is not intended to be a review in the classical way because it deals with parasites ranging from Protozoa to Arthropoda.

Marine fish parasitology in South Africa: history of discovery and future direction

Almost 200 years have passed since the first description of a marine fish parasite from South Africa. It is therefore an opportune time to look back, take stock of and reflect on the history of discovery within this field and, based on what we know, propose the future direction for research. The aim of this paper is hence to provide some background information on the growth in our knowledge and understanding of the major groups of marine fish parasites and to give an account of how pioneers, such as Barnard, Stebbing, Fantham and Kensley, led the age of discovery and exploration in marine fish parasitology in South Africa. The paper also presents a brief overview of the contributions made by internationally acclaimed parasitologists, such as Rodney Bray and Angela Davies, to our knowledge of marine fish parasites from this region and also to acknowledge the role played by the South African parasitologists, especially over the past 30 years. A rich base of fundamental knowledge is available in South Africa and this research field continues to grow. The prognosis for the future of marine parasitology in South Africa is good; however, as we continue to acquire and record new information about species, it is proposed that future research should be more focused on the lesser studied groups, such as monogeneans, protists and Myxozoa, as these have received uneven attention to date. In addition, it is proposed that the scope of research on marine fish parasitology be broadened to include ecological and applied aspects, using modern techniques.

Parasites of Freshwater Fishes In North America: Why So Neglected?

Fish parasitology has a long tradition in North America and numerous parasitologists have contributed considerably to the current knowledge of the diversity and biology of protistan and metazoan parasites of freshwater fishes. The Journal of Parasitology has been essential in disseminating this knowledge and remains a significant contributor to our understanding of fish parasites in North America as well as more broadly at the international level. However, with a few exceptions, the importance of fish parasites has decreased during the last decades, which is reflected in the considerable decline of funding and corresponding decrease of attention paid to these parasites in Canada and the United States of America. After the 'golden age' in the second half of the 20th Century, fish parasitology in Canada and the United States went in a new direction, driven by technology and a shift in priorities. In contrast, fish parasitology in Mexico has undergone rapid development since the early 1990s, partly due to extensive international collaboration and governmental funding. A critical review of the current data on the parasites of freshwater fishes in North America has revealed considerable gaps in the knowledge of their species composition, host specificity, life cycles, evolution, phylogeography, and relationships with their fish hosts. As to the key question, "Why so neglected?" this is probably because: (1) fish parasites are not in the forefront due to their lesser economic importance; (2) there is little funding for this kind of research, especially if a practical application is not immediately apparent; and (3) of shifting interests and a shortage of key personalities to train a new generation (they switched to marine habitats or other fields). Some of the opportunities for future research are outlined, such as climate change and cryptic species diversity. A significant problem challenging future research seems to be the loss of trained and experienced fish parasitologists. This has 2 major ramifications: the loss of expertise in identifying organisms that other biologists (e.g., ecologists, molecular biologists, evolutionists) work with, and an incomplete comprehension of ecosystem structure and function in the face of climate change, emerging diseases, and loss of biodiversity.

English

  Fish parasitology is an indispensable tool in aquatic health studies and a basic understanding of richness of a community parasitism in many localities is essential for instituting control. Many copepod parasites are ecto-parasites which negatively affect the appearance and reduced production of species of economically important fish, both from the wild and fish farms, thus making them difficult to market. In this study, copepod parasitic investigation was carried out in gills of 856 fish mugilidae (Mugil cephalus and Liza falcipinnis) in three stations (Ganvie, Djdje and Zogbo) of Lac Nokoue lagoon. In the three stations, three species of parasitic copepod were found: Nipergasilus bora, Ergasilus latus and Ergasilus lizae. The highest total percentage copepod prevalence was found in Ganvie (86.23%) and the least in Djdje (63.14%). There is significant difference (P<0.05) in the rate of infestation of L. falcipinnis at Djdje than the other two stations, where as M. cephalus shows no significant difference in the rate of infestation in the three stations. The research reveals higher number of parasite copepods during the rainy season.     Key words: Copepod parasites, Mugilidae fish, Lac Nokoue Lagoon.

Occurrence of cymothoid isopod from Miri, East Malaysian marine fishes.

To identify the isopod parasite, which has been recorded from Miri, East Malaysian marine fishes. During the present study, four cymothoid isopods are reported three genera, including Cymothoa eremita, Lobothorax typus, Nerocila longispina and Nerocila loveni. Nerocila longispina and N. loveni are also previously reported from Malaysia and two additional cymothoids C. eremita and L. typus are reported for the first record of Miri coast, East Malaysia. New hosts were identified for N. loveni on Chirocentrus dorab for the first time in the world fauna. The Parasitological indexes were calculated. The site of attachment of the parasites on their hosts was also observed. These parasites can cause the damage in gill, eye and internal organ including swim bladder. Marine fish parasitology is a rapidly developing field of aquatic science.

How to catch a parasite: Parasite Niche Modeler (PaNic) meets Fishbase

Parasite Niche Modeler (PaNic) is a free online software tool that suggests potential hosts for fish parasites. For a particular parasite species from the major helminth groups (Acanthocephala, Cestoda, Monogenea, Nematoda, Trematoda), PaNic takes data from known hosts (maximum body length, growth rate, life span, age at first maturity, trophic level, phylogeny, and biogeography) and hypothesizes similar fish species that might serve as hosts to that parasite. Users can give varying weights to host attributes and create custom models. In addition to suggesting plausible hosts (with varying degrees of confidence), the models indicate known host species that appear to be outliers in comparison to other known hosts. These unique features make PaNic an innovative tool for addressing both theoretical and applied questions in fish parasitology. PaNic can be accessed at <http://purl.oclc.org/fishpest>.

Metazoan parasite species richness in Neotropical fishes: hotspots and the geography of biodiversity

Although research on parasite biodiversity has intensified recently, there are signs that parasites remain an underestimated component of total biodiversity in many regions of the planet. To identify geographical hotspots of parasite diversity, we performed qualitative and quantitative analyses of the parasite-host associations in fishes from Latin America and the Caribbean, a region that includes known hotspots of plant and animal biodiversity. The database included 10,904 metazoan parasite-host associations involving 1660 fish species. The number of host species with at least 1 parasite record was less than 10% of the total known fish species in the majority of countries. Associations involving adult endoparasites in actinopterygian fish hosts dominated the database. Across the whole region, no significant difference in parasite species richness was detected between marine and freshwater fishes. As a rule, host body size and study effort (number of studies per fish species) were good predictors of parasite species richness. Some interesting patterns emerged when we included only the regions with highest fish species biodiversity and study effort (Brazil, Mexico and the Caribbean Islands). Independently of differences in study effort or host body sizes, Mexico stands out as a hotspot of parasite diversity for freshwater fishes, as does Brasil for marine fishes. However, among 57 marine fish species common to all 3 regions, populations from the Caribbean consistently harboured more parasite species. These differences may reflect true biological patterns, or regional discrepancies in study effort and local priorities for fish parasitology research.