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Schwantes U. Impact of anthropogenous environmental factors on the marine ecosystem of trophically transmitted helminths and hosting seabirds: Focus on North Atlantic, North Sea, Baltic and the Arctic seas. Helminthologia 2023; 60:300-326. [PMID: 38222492 PMCID: PMC10787638 DOI: 10.2478/helm-2023-0034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Accepted: 09/21/2023] [Indexed: 01/16/2024] Open
Abstract
Alongside natural factors, human activities have a major impact on the marine environment and thus influence processes in vulnerable ecosystems. The major purpose of this review is to summarise the current understanding as to how manmade factors influence the marine biocenosis of helminths, their intermediate hosts as well as seabirds as their final hosts. Moreover, it highlights current knowledge gaps regarding this ecosystem, which should be closed in order to gain a more complete understanding of these interactions. This work is primarily focused on helminths parasitizing seabirds of the North Atlantic and the Arctic Ocean. The complex life cycles of seabird helminths may be impacted by fishing and aquaculture, as they interfere with the abundance of fish and seabird species, while the latter also affects the geographical distribution of intermediate hosts (marine bivalve and fish species), and may therefore alter the intertwined marine ecosystem. Increasing temperatures and seawater acidification as well as environmental pollutants may have negative or positive effects on different parts of this interactive ecosystem and may entail shifts in the abundance or regional distribution of parasites and/or intermediate and final hosts. Organic pollutants and trace elements may weaken the immune system of the hosting seabirds and hence affect the final host's ability to control the endoparasites. On the other hand, in some cases helminths seem to function as a sink for trace elements resulting in decreased concentrations of heavy metals in birds' tissues. Furthermore, this article also describes the role of helminths in mass mortality events amongst seabird populations, which beside natural causes (weather, viral and bacterial infections) have anthropogenous origin as well (e.g. oil spills, climate change, overfishing and environmental pollution).
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Affiliation(s)
- U. Schwantes
- Verein Jordsand zum Schutz der Seevögel und der Natur e.V., Ahrensburg, Germany
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2
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Ben Youssef-Dridi S, Antar R, Gey D, Justine JL, Gargouri L. Morphological and molecular studies of the life-cycle stages of the monorchiid Monorchis parvus (Looss, 1902) (Digenea) from the Southern Mediterranean coast (Tunisia). Parasitol Res 2023; 122:2819-2833. [PMID: 37749315 DOI: 10.1007/s00436-023-07967-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2022] [Accepted: 09/02/2023] [Indexed: 09/27/2023]
Abstract
The elucidation of life-cycles of digeneans, with their successive larval stages, is facilitated by the use of molecular markers. Samples of sporocysts containing cercariae and metacercariae belonging to Monorchis Monticelli, 1893 were collected from naturally infected bivalves, Cerastoderma glaucum (Bruguière, 1789), and adult forms of Monorchis spp. were collected from sparid fishes of the genus Diplodus. All specimens were collected in the Gulf of Gabès, southern Tunisia. The identities of the examined molluscs and fishes were determined via molecular barcoding of their COI gene. Sequences of COI and ITS1 genes were also obtained for both larval and adult stages of collected parasite specimens. Genetic sequence data generated for the collected larval specimens only differed minimally from the sequence data of adults identified as Monorchis parvus; we attribute the difference to intraspecific variation. The morpho-anatomical study showed that the different stages of M. parvus collected from the Tunisian coasts had the same morphology as those reported in European waters with a lag in maturity and lower measurements. The species is recorded and molecularly characterised for the first time off the Tunisian coasts.
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Affiliation(s)
- Soumaya Ben Youssef-Dridi
- Faculty of Sciences of Tunis, Laboratory of Diversity, Management and Conservation of Biological Systems, University of Tunis El Manar, LR18ES06, Tunis, Tunisia.
| | - Rym Antar
- Faculty of Sciences of Tunis, Laboratory of Diversity, Management and Conservation of Biological Systems, University of Tunis El Manar, LR18ES06, Tunis, Tunisia
| | - Delphine Gey
- Service de Systématique Moléculaire, UMS 2700 CNRS, Muséum National d'Histoire Naturelle, Sorbonne Université, CP 26, 43 Rue Cuvier, 75231 Cedex 05, Paris, France
| | - Jean-Lou Justine
- Institut de Systématique, Évolution, Biodiversité (ISYEB), MNHN, CNRS, Sorbonne Université, EPHE, Université des Antilles, Muséum National d'Histoire Naturelle, 57 Rue Cuvier, CP 51, 75005, Paris, France
| | - Lamia Gargouri
- Faculty of Sciences of Tunis, Laboratory of Diversity, Management and Conservation of Biological Systems, University of Tunis El Manar, LR18ES06, Tunis, Tunisia
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Correia S, Fernández-Boo S, Magalhães L, de Montaudouin X, Daffe G, Poulin R, Vera M. Trematode genetic patterns at host individual and population scales provide insights about infection mechanisms. Parasitology 2023; 150:1207-1220. [PMID: 38084628 PMCID: PMC10941227 DOI: 10.1017/s0031182023000987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 10/02/2023] [Accepted: 10/07/2023] [Indexed: 01/10/2024]
Abstract
Multiple parasites can infect a single host, creating a dynamic environment where each parasite must compete over host resources. Such interactions can cause greater harm to the host than single infections and can also have negative consequences for the parasites themselves. In their first intermediate hosts, trematodes multiply asexually and can eventually reach up to 20% of the host's biomass. In most species, it is unclear whether this biomass results from a single infection or co-infection by 2 or more infective stages (miracidia), the latter being more likely a priori in areas where prevalence of infection is high. Using as model system the trematode Bucephalus minimus and its first intermediate host cockles, we examined the genetic diversity of the cytochrome c oxidase subunit I region in B. minimus from 3 distinct geographical areas and performed a phylogeographic study of B. minimus populations along the Northeast Atlantic coast. Within localities, the high genetic variability found across trematodes infecting different individual cockles, compared to the absence of variability within the same host, suggests that infections could be generally originating from a single miracidium. On a large spatial scale, we uncovered significant population structure of B. minimus, specifically between the north and south of Bay of Biscay. Although other explanations are possible, we suggest this pattern may be driven by the population structure of the final host.
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Affiliation(s)
- Simão Correia
- Department of Biology, CESAM, University of Aveiro, 3810-193 Aveiro, Portugal
- Aquatic and Animal Health Group, CIIMAR, University of Porto, 4450-208 Matosinhos, Portugal
- Department of Zoology, Genetics and Physical Anthropology, Campus Terra, University of Santiago de Compostela, 27002 Lugo, Spain
- Department of Zoology, University of Otago, 9054 Dunedin, New Zealand
| | - Sergio Fernández-Boo
- Aquatic and Animal Health Group, CIIMAR, University of Porto, 4450-208 Matosinhos, Portugal
| | - Luísa Magalhães
- Department of Biology, CESAM, University of Aveiro, 3810-193 Aveiro, Portugal
| | | | - Guillemine Daffe
- Université de Bordeaux, CNRS, Observatoire Aquitain des Sciences de l'Univers, F-33615 Pessac, France
| | - Robert Poulin
- Department of Zoology, University of Otago, 9054 Dunedin, New Zealand
| | - Manuel Vera
- Department of Zoology, Genetics and Physical Anthropology, Campus Terra, University of Santiago de Compostela, 27002 Lugo, Spain
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Lamine I, Chahouri A, Moukrim A, Ait Alla A. The impact of climate change and pollution on trematode-bivalve dynamics. MARINE ENVIRONMENTAL RESEARCH 2023; 191:106130. [PMID: 37625953 DOI: 10.1016/j.marenvres.2023.106130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 08/06/2023] [Accepted: 08/08/2023] [Indexed: 08/27/2023]
Abstract
Coastal ecosystems and their marine populations are increasingly threatened by global environmental changes. Bivalves have emerged as crucial bioindicators within these ecosystems, offering valuable insights into biodiversity and overall ecosystem health. In particular, bivalves serve as hosts to trematode parasites, making them a focal point of study. Trematodes, with their life cycles intricately linked to external factors, provide excellent indicators of environmental changes and exhibit a unique ability to accumulate pollutants beyond ambient levels. Thus, they act as living sentinels, reflecting the ecological condition of their habitats. This paper presents a comprehensive review of recent research on the use of bivalve species as hosts for trematodes, examining the interactions between these organisms. The study also investigates the combined impact of trematode infections and other pollutants on bivalve molluscs. Trematode infections have multifaceted consequences for bivalve species, influencing various aspects of their physiology and behavior, including population-wide mortality. Furthermore, the coexistence of trematode infections and other sources of pollution compromises host resistance, disrupts parasite transmission, and reduces the abundance of intermediate hosts for complex-living parasites. The accumulation process of these parasites is influenced not only by external factors but also by host physiology. Consequently, the implications of climate change and environmental factors, such as temperature, salinity, and ocean acidification, are critical considerations. In summary, the intricate relationship between bivalves, trematode parasites, and their surrounding environment provides valuable insights into the health and sustainability of coastal ecosystems. A comprehensive understanding of these interactions, along with the influence of climate change and environmental parameters, is essential for effective management and conservation strategies aimed at preserving these delicate ecosystems and the diverse array of species that rely on them.
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Affiliation(s)
- Imane Lamine
- Laboratory of Aquatic Systems: Marine and Continental Ecosystems, Department of Biology, Faculty of Sciences, Ibn Zohr University, BP 8106, Agadir, Morocco.
| | - Abir Chahouri
- Laboratory of Aquatic Systems: Marine and Continental Ecosystems, Department of Biology, Faculty of Sciences, Ibn Zohr University, BP 8106, Agadir, Morocco
| | | | - Aicha Ait Alla
- Laboratory of Aquatic Systems: Marine and Continental Ecosystems, Department of Biology, Faculty of Sciences, Ibn Zohr University, BP 8106, Agadir, Morocco
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Benito D, Izagirre U, Lekube X, Zaldibar B, Villalba A, De Montaudouin X, Daffe G, Soto M, Diaz de Cerio O. Molecular confirmation of pearl formation in arctic mussels ( Mytilus edulis) caused by Gymnophallus bursicola (Odhner 1900) metacercariae. Parasitology 2023; 150:1015-1021. [PMID: 37705257 PMCID: PMC10801375 DOI: 10.1017/s0031182023000860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 08/21/2023] [Accepted: 09/06/2023] [Indexed: 09/15/2023]
Abstract
In recent field studies, suspected gymnophallid metacercariae were histologically located in the mantle of mussels from the Norwegian Sea. Mussels from the sites in which that infection was detected also presented abnormally high pearl numbers. It has been previously described that gymnophallid metacercariae could cause pearl formation processes in mussels, as a host reaction to encapsulate these metacercariae. Given the pathological host reaction these parasites elicit, a study was performed to identify gymnophallid metacercariae found in mussels collected from Tromsø at morphological and molecular level and to assess, by the use of molecular tools, the relationship between the parasite and the biological material inside the pearls. As a result, Gymnophallus bursicola metacercariae infecting Norwegian Mytilus edulis were identified according to morphological characters, along with the first 18S rDNA and COI sequences for this trematode species. In addition, parasite DNA from the core of the pearls was extracted and amplified for the first time, confirming the parasitological origin of these pearls. This procedure could allow identifying different parasitic organisms responsible for the generation of pearls in bivalves.
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Affiliation(s)
- Denis Benito
- CBET Research Group, Department of Zoology & Animal Cell Biology, University of the Basque Country (UPV/EHU), Areatza Hiribidea 47, 48620 Plentzia, Basque Country, Spain
- Faculty of Science & Technology and Research Centre for Experimental Marine Biology and Biotechnology (PiE-UPV/EHU), University of the Basque Country (UPV/EHU), Areatza Hiribidea 47, 48620 Plentzia, Basque Country, Spain
- Research Centre for Experimental Marine Biology and Biotechnology (PiE-UPV/EHU), University of the Basque Country (UPV/EHU), Areatza Hiribidea 47, 48620 Plentzia, Basque Country, Spain
| | - Urtzi Izagirre
- CBET Research Group, Department of Zoology & Animal Cell Biology, University of the Basque Country (UPV/EHU), Areatza Hiribidea 47, 48620 Plentzia, Basque Country, Spain
- Faculty of Science & Technology and Research Centre for Experimental Marine Biology and Biotechnology (PiE-UPV/EHU), University of the Basque Country (UPV/EHU), Areatza Hiribidea 47, 48620 Plentzia, Basque Country, Spain
- Research Centre for Experimental Marine Biology and Biotechnology (PiE-UPV/EHU), University of the Basque Country (UPV/EHU), Areatza Hiribidea 47, 48620 Plentzia, Basque Country, Spain
- Biscay Bay Environmental Biospecimen Bank (BBEBB), University of the Basque Country (UPV/EHU), Areatza Hiribidea 47, 48620 Plentzia, Basque Country, Spain
| | - Xabier Lekube
- CBET Research Group, Department of Zoology & Animal Cell Biology, University of the Basque Country (UPV/EHU), Areatza Hiribidea 47, 48620 Plentzia, Basque Country, Spain
- Faculty of Science & Technology and Research Centre for Experimental Marine Biology and Biotechnology (PiE-UPV/EHU), University of the Basque Country (UPV/EHU), Areatza Hiribidea 47, 48620 Plentzia, Basque Country, Spain
- Research Centre for Experimental Marine Biology and Biotechnology (PiE-UPV/EHU), University of the Basque Country (UPV/EHU), Areatza Hiribidea 47, 48620 Plentzia, Basque Country, Spain
- Biscay Bay Environmental Biospecimen Bank (BBEBB), University of the Basque Country (UPV/EHU), Areatza Hiribidea 47, 48620 Plentzia, Basque Country, Spain
| | - Beñat Zaldibar
- CBET Research Group, Department of Zoology & Animal Cell Biology, University of the Basque Country (UPV/EHU), Areatza Hiribidea 47, 48620 Plentzia, Basque Country, Spain
- Faculty of Science & Technology and Research Centre for Experimental Marine Biology and Biotechnology (PiE-UPV/EHU), University of the Basque Country (UPV/EHU), Areatza Hiribidea 47, 48620 Plentzia, Basque Country, Spain
- Research Centre for Experimental Marine Biology and Biotechnology (PiE-UPV/EHU), University of the Basque Country (UPV/EHU), Areatza Hiribidea 47, 48620 Plentzia, Basque Country, Spain
| | - Antonio Villalba
- Research Centre for Experimental Marine Biology and Biotechnology (PiE-UPV/EHU), University of the Basque Country (UPV/EHU), Areatza Hiribidea 47, 48620 Plentzia, Basque Country, Spain
- Centro de Investigacións Mariñas (CIMA), Consellería do Mar, Xunta de Galicia, 36620 Vilanova de Arousa, Spain
- Departamento de Ciencias de la Vida, Universidad de Alcalá, 28871 Alcalá de Henares, Spain
| | | | - Guillemine Daffe
- University of Bordeaux, CNRS, Observatoire Aquitain des Sciences de l'Univers, UAR 2567 POREA, F-33615 Pessac, France
| | - Manu Soto
- CBET Research Group, Department of Zoology & Animal Cell Biology, University of the Basque Country (UPV/EHU), Areatza Hiribidea 47, 48620 Plentzia, Basque Country, Spain
- Faculty of Science & Technology and Research Centre for Experimental Marine Biology and Biotechnology (PiE-UPV/EHU), University of the Basque Country (UPV/EHU), Areatza Hiribidea 47, 48620 Plentzia, Basque Country, Spain
- Research Centre for Experimental Marine Biology and Biotechnology (PiE-UPV/EHU), University of the Basque Country (UPV/EHU), Areatza Hiribidea 47, 48620 Plentzia, Basque Country, Spain
- Biscay Bay Environmental Biospecimen Bank (BBEBB), University of the Basque Country (UPV/EHU), Areatza Hiribidea 47, 48620 Plentzia, Basque Country, Spain
| | - Oihane Diaz de Cerio
- CBET Research Group, Department of Zoology & Animal Cell Biology, University of the Basque Country (UPV/EHU), Areatza Hiribidea 47, 48620 Plentzia, Basque Country, Spain
- Faculty of Science & Technology and Research Centre for Experimental Marine Biology and Biotechnology (PiE-UPV/EHU), University of the Basque Country (UPV/EHU), Areatza Hiribidea 47, 48620 Plentzia, Basque Country, Spain
- Research Centre for Experimental Marine Biology and Biotechnology (PiE-UPV/EHU), University of the Basque Country (UPV/EHU), Areatza Hiribidea 47, 48620 Plentzia, Basque Country, Spain
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Mahony KE, Lynch SA, de Montaudouin X, Culloty SC. Extrinsic and intrinsic drivers of parasite prevalence and parasite species richness in a marine bivalve. PLoS One 2022; 17:e0274474. [PMID: 36155981 PMCID: PMC9512183 DOI: 10.1371/journal.pone.0274474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 08/29/2022] [Indexed: 11/23/2022] Open
Abstract
Parasite species richness is influenced by a range of drivers including host related factors (e.g. host size) and environmental factors (e.g. seawater temperature). However, identification of modulators of parasite species richness remains one of the great unanswered questions in ecology. The common cockle Cerastoderma edule is renowned for its diversity and abundance of parasites, yet drivers of parasite species richness in cockles have not been examined to investigate the association of both macro and microparasite communities. Using cockles as a model species, some of the key drivers of parasite prevalence and parasite species richness were investigated. Objectives of this 19-month survey were to determine the influence of the environment, host-parasite dynamics and parasite associations on parasite species richness and prevalence at two different geographic latitudes, chosen based on environmental differences. The highest parasite species richness was recorded in the northern sites, and this was potentially influenced by a range of interactions between the host, the pathogens and the environment. Parasite prevalence increased with host size and age, and parasite species richness increased with reduced salinity. A number of interactions between parasites, and between parasites and pathologies may be influencing parasite infection dynamics. New and concerning information is also presented regarding interactions between parasites and their environment. A number of parasites and potential pathogens (bacteria, Trichodina ciliates, metacercariae, trematode sporocysts) may be advantaged under climate change conditions (warming seas, increased precipitation), increasing disease incidence, which may prove detrimental not just for cockles, but for other bivalve species in the future.
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Affiliation(s)
- Kate E. Mahony
- School of Biological, Earth and Environmental Sciences, University College Cork, Cork, Republic of Ireland
- Aquaculture and Fisheries Development Centre (AFDC), Environmental Research Institute, University College Cork, Cork, Republic of Ireland
- MaREI Centre for Climate, Energy and Marine, Environmental Research Institute (ERI), University College Cork, Cork, Republic of Ireland
| | - Sharon A. Lynch
- School of Biological, Earth and Environmental Sciences, University College Cork, Cork, Republic of Ireland
- Aquaculture and Fisheries Development Centre (AFDC), Environmental Research Institute, University College Cork, Cork, Republic of Ireland
- MaREI Centre for Climate, Energy and Marine, Environmental Research Institute (ERI), University College Cork, Cork, Republic of Ireland
- * E-mail:
| | - Xavier de Montaudouin
- Université de Bordeaux, CNRS, UMR 5805 EPOC, Station Marine d’Arcachon, Arcachon, France
| | - Sarah C. Culloty
- School of Biological, Earth and Environmental Sciences, University College Cork, Cork, Republic of Ireland
- Aquaculture and Fisheries Development Centre (AFDC), Environmental Research Institute, University College Cork, Cork, Republic of Ireland
- MaREI Centre for Climate, Energy and Marine, Environmental Research Institute (ERI), University College Cork, Cork, Republic of Ireland
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Richard A, Maire O, Daffe G, Magalhães L, de Montaudouin X. Himasthla spp. (Trematoda) In The Edible Cockle Cerastoderma edule: Review, Long-Term Monitoring And New Molecular Insights. Parasitology 2022; 149:1-52. [PMID: 35352675 PMCID: PMC10090617 DOI: 10.1017/s0031182022000373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 03/18/2022] [Accepted: 03/18/2022] [Indexed: 11/06/2022]
Abstract
Trematodes are the main macroparasites in coastal waters. The most abundant and widespread form of these parasites is metacercaria. Their impact on their host fitness is considered relatively low but metacercarial larvae of some species can have deleterious effects on individuals and/or populations. This review focused on the cockle Cerastoderma edule and four species of the genus Himasthla ; a common host–parasite system in marine coastal environments. Our aims were (1) to review literature concerning Himasthla continua , Himasthla elongata , Himasthla interrupta and Himasthla quissetensis in cockles; (2) to provide molecular signatures of these parasites and (3) to analyse infection patterns using a 20-year monthly database of cockle monitoring from Banc d'Arguin (France). Due to identification uncertainties, the analysis of the database was restricted to H. interrupta and H. quissetensis , and it was revealed that these parasites infect cockles of the same size range. The intensity of parasites increased with cockle size/age. During the colder months, the mean parasite intensity of a cockle cohort decreased, while infection occurred in the warmest season. No inter-specific competition between trematode parasites was detected. Furthermore, even if the intensity of H. interrupta or H. quissetensis infection fluctuated in different years, this did not modify the trematode community structure in the cockles. The intensity of infection of both species was also positively correlated with trematode species richness and metacercarial abundance. This study highlighted the possible detrimental role of Himasthla spp. in cockle population dynamics. It also revealed the risks of misidentification, which should be resolved by further molecular approaches.
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Affiliation(s)
- Anaïs Richard
- UMR 5805, EPOC UMR, OASU, Université de Bordeaux, F33120 Arcachon, France
| | - Olivier Maire
- UMR 5805, EPOC UMR, OASU, Université de Bordeaux, F33120 Arcachon, France
| | - Guillemine Daffe
- Université de Bordeaux, CNRS, Observatoire Aquitain des Sciences de l'Univers, UMS 2567 POREA, F-33615 Pessac, France
| | - Luísa Magalhães
- CESAM – Centre for Environmental and Marine Studies, Departamento de Biologia, Universidade de Aveiro, 3810-193 Aveiro, Portugal
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Cockle as Second Intermediate Host of Trematode Parasites: Consequences for Sediment Bioturbation and Nutrient Fluxes across the Benthic Interface. JOURNAL OF MARINE SCIENCE AND ENGINEERING 2021. [DOI: 10.3390/jmse9070749] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Trematode parasites are distributed worldwide and can severely impact host populations. However, their influence on ecosystem functioning through the alteration of host engineering behaviours remains largely unexplored. This study focuses on a common host parasite system in marine coastal environments, i.e., the trematode Himasthla elongata, infecting the edible cockle Cerastoderma edule as second intermediate host. A laboratory experiment was conducted to investigate the indirect effects of metacercarial infection on sediment bioturbation and biogeochemical fluxes at the sediment water interface. Our results revealed that, despite high parasite intensity, the sediment reworking and bioirrigation rates, as well as nutrient fluxes, were not impacted. This finding was unexpected since previous studies showed that metacercarial infection impairs the physiological condition of cockles and induces a mechanical obstruction of their feet, thus altering their burrowing capacity. There are several explanations for such contrasting results. Firstly, the alteration of cockle behavior could arise over a longer time period following parasite infection. Secondly, the modulation of cockle bioturbation by parasites could be more pronounced in older specimens burying deeper. Thirdly, the intensity of the deleterious impacts of metacercariae could strongly vary across parasite species. Lastly, metacercarial infection alters cockle fitness through an interaction with other biotic and abiotic environmental stressors.
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Hill-Spanik KM, Sams C, Connors VA, Bricker T, de Buron I. Molecular data reshape our understanding of the life cycles of three digeneans (Monorchiidae and Gymnophallidae) infecting the bivalve, Donax variabilis: it's just a facultative host! ACTA ACUST UNITED AC 2021; 28:34. [PMID: 33835020 PMCID: PMC8034251 DOI: 10.1051/parasite/2021027] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 03/11/2021] [Indexed: 11/15/2022]
Abstract
The coquina, Donax variabilis, is a known intermediate host of monorchiid and gymnophallid digeneans. Limited morphological criteria for the host and the digeneans' larval stages have caused confusion in records. Herein, identities of coquinas from the United States (US) Atlantic coast were verified molecularly. We demonstrate that the current GenBank sequences for D. variabilis are erroneous, with the US sequence referring to D. fossor. Two cercariae and three metacercariae previously described in the Gulf of Mexico and one new cercaria were identified morphologically and molecularly, with only metacercariae occurring in both hosts. On the Southeast Atlantic coast, D. variabilis' role is limited to being a facultative second intermediate host, and D. fossor, an older species, acts as both first and second intermediate hosts. Sequencing demonstrated 100% similarities between larval stages for each of the three digeneans. Sporocysts, single tail cercariae, and metacercariae in the incurrent siphon had sequences identical to those of monorchiid Lasiotocus trachinoti, for which we provide the complete life cycle. Adults are not known for the other two digeneans, and sequences from their larval stages were not identical to any in GenBank. Large sporocysts, cercariae (Cercaria choanura), and metacercariae in the coquinas' foot were identified as Lasiotocus choanura (Hopkins, 1958) n. comb. Small sporocysts, furcocercous cercariae, and metacercariae in the mantle were identified as gymnophallid Parvatrema cf. donacis. We clarify records wherein authors recognized the three digenean species but confused their life stages, and probably the hosts, as D. variabilis is sympatric with cryptic D. texasianus in the Gulf of Mexico.
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Affiliation(s)
- Kristina M Hill-Spanik
- Department of Biology, 205 Fort Johnson Road, College of Charleston, Charleston, 29412 SC, USA
| | - Claudia Sams
- Department of Biology, 205 Fort Johnson Road, College of Charleston, Charleston, 29412 SC, USA
| | - Vincent A Connors
- Department of Biology, Division of Natural Sciences, University of South Carolina Upstate, 1800 University Way, Spartanburg, 29303 SC, USA
| | - Tessa Bricker
- Department of Biology, 205 Fort Johnson Road, College of Charleston, Charleston, 29412 SC, USA
| | - Isaure de Buron
- Department of Biology, 205 Fort Johnson Road, College of Charleston, Charleston, 29412 SC, USA
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