1
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Myrenås E, Näslund J, Persson J, Sundin J. Effects of the invasive swim bladder parasite Anguillicola crassus on health and condition indicators in the European eel. JOURNAL OF FISH DISEASES 2023; 46:1029-1047. [PMID: 37329520 DOI: 10.1111/jfd.13822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 05/30/2023] [Accepted: 05/31/2023] [Indexed: 06/19/2023]
Abstract
Parasites negatively affect biological processes within their hosts, which may alter for example health, growth, and reproductive ability. Non-native invasive parasites, in particular, may have large effects on the endemic hosts, given that the hosts lack evolved specific defences against such parasites. The swim bladder nematode Anguillicola crassus, an invasive parasite originating from Asia, is found in the European eel (Anguilla anguilla, L. 1758), since the 1980s. We investigated whether A. crassus affected several indicators related to health of the European eel (spleen- and liver size, body fat content and relative condition). Our results indicate that during the continental residency of the eels, infection by A. crassus had no major negative impacts on the investigated health indicators at the generally low infection intensities present in this study (median 2-3 visible parasites). Given that many of the adult eels were found to have swim bladder damage, concerns about their spawning migration through deeper oceanic environments can still be raised. To allow further investigations, we suggest that quantification of swim bladder damage should be implemented in eel-monitoring programs. Compared to other parasite pressure parameters, swim bladder damage provides additional information about past infections and future problems.
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Affiliation(s)
- Elin Myrenås
- Department of Aquatic Resources, Institute of Freshwater Research, Swedish University of Agricultural Sciences, Drottningholm, Sweden
| | - Joacim Näslund
- Department of Aquatic Resources, Institute of Freshwater Research, Swedish University of Agricultural Sciences, Drottningholm, Sweden
| | - John Persson
- Department of Aquatic Resources, Institute of Freshwater Research, Swedish University of Agricultural Sciences, Drottningholm, Sweden
| | - Josefin Sundin
- Department of Aquatic Resources, Institute of Freshwater Research, Swedish University of Agricultural Sciences, Drottningholm, Sweden
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2
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Dezfuli BS, Maestri C, Lorenzoni M, Carosi A, Maynard BJ, Bosi G. The impact of Anguillicoloides crassus (Nematoda) on European eel swimbladder: histopathology and relationship between neuroendocrine and immune cells. Parasitology 2021; 148:612-622. [PMID: 33557973 PMCID: PMC10950382 DOI: 10.1017/s0031182021000032] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 11/04/2020] [Accepted: 11/05/2020] [Indexed: 12/13/2022]
Abstract
The swimbladder functions as a hydrostatic organ in most bony fishes, including the European eel, Anguilla anguilla. Infection by the nematode Anguillicoloides crassus impairs swimbladder function, significantly compromising the success of the eel spawning migration. Swimbladders from 32 yellow eels taken from Lake Trasimeno (Central Italy) were analysed by histopathology- and electron microscopy-based techniques. Sixteen eels (50%) harboured A. crassus in their swimbladders and intensity of infection ranged from 2 to 17 adult nematodes per organ (6.9 ± 1.6, mean ± s.e.). Gross observations of heavily infected swimbladders showed opacity and histological analysis found a papillose aspect to the mucosa and hyperplasia of the lamina propria, muscularis mucosae and submucosa. Inflammation, haemorrhages, dilation of blood vessels and epithelial erosion were common in infected swimbladders. In the epithelium of parasitized swimbladders, many empty spaces and lack of apical junctional complexes were frequent among the gas gland cells. In heavily infected swimbladders, we observed hyperplasia, cellular swelling and abundant vacuolization in the apical portion of the gas gland cells. Numerous mast cells and several macrophage aggregates were noticed in the mucosal layer of infected swimbladders. We found more nervous and endocrine elements immunoreactive to a panel of six rabbit polyclonal antibodies in infected swimbladders compared to uninfected.
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Affiliation(s)
- Bahram Sayyaf Dezfuli
- Department of Life Sciences and Biotechnology, University of Ferrara, St. Borsari 46, 44121Ferrara, Italy
| | - Chiara Maestri
- Department of Life Sciences and Biotechnology, University of Ferrara, St. Borsari 46, 44121Ferrara, Italy
| | - Massimo Lorenzoni
- Department of Cellular and Environmental Biology, University of Perugia, St. Elce di sotto 5, 06123Perugia, Italy
| | - Antonella Carosi
- Department of Cellular and Environmental Biology, University of Perugia, St. Elce di sotto 5, 06123Perugia, Italy
| | - Barbara J Maynard
- The Institute for Learning and Teaching, Colorado State University, Fort Collins, CO80523, USA
| | - Giampaolo Bosi
- Department of Health, Animal Science and Food Safety, Università degli Studi di Milano, St. Trentacoste 2, 20134Milan, Italy
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3
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Honka KI, Sures B. Mutual adaptations between hosts and parasites determine stress levels in eels. INTERNATIONAL JOURNAL FOR PARASITOLOGY-PARASITES AND WILDLIFE 2021; 14:179-184. [PMID: 33898218 PMCID: PMC8056127 DOI: 10.1016/j.ijppaw.2021.02.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 02/02/2021] [Accepted: 02/02/2021] [Indexed: 12/02/2022]
Abstract
Invasive parasites may severely affect their new hosts. Two invasive parasites occurring in the European eel (Anguilla anguilla) are the Asian swim bladder nematode Anguillicola crassus and the Ponto-caspian acanthocephalan Pomphorhynchus sp., which were introduced to the river Rhine in the early 1980/90s. The Japanese eel (Anguilla japonica), as the native host of A. crassus, developed mutual adaptations to the swim bladder parasite, which are lacking in the European eel. Therefore, after its spread to Europe, infestations of European eels with A. crassus were found to be more severe and caused massive swim bladder wall damages mainly due to the feeding activity of the adult nematodes. A suppression of the immune system also appears to be likely, which allows secondary infections e.g. by bacteria or other parasites in European eels. Acanthocephalans of the genus Pomphorhynchus have not been described so far in Japanese eels, in contrast to European eels, which regularly show infestations with Pomphorhynchus sp. By using these differentially adapted host-parasite associations for experimental studies, host stress responses were examined in the present study in relation to the degree of mutual adaptations between eel hosts and parasites. Under laboratory conditions, Japanese and European eels were each inoculated with A. crassus and Pomphorhynchus sp., respectively, to investigate their stress responses against differently adapted parasites. The stress response was determined by analyzing plasma levels of cortisol, which is the main corticosteroid hormone during stress response of fish. The results show a strong cortisol release in European eels after infestation with A. crassus whereas Japanese eels only react against Pomphorhynchus sp. infestations. These results are consistent with the initial hypothesis that a low degree of host-parasite adaptations lead to stronger host stress responses against the parasite. We measured cortisol as the main corticosteroid hormone in fish. Japanese and European eels were inoculated with A. crassus and Pomphorhynchus sp. Lower mutual adaptations lead to a higher stress response in host-parasite-systems.
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Affiliation(s)
- K I Honka
- Aquatic Ecology, University of Duisburg-Essen, D-45141, Universitätsstr. 5, Germany
| | - B Sures
- Aquatic Ecology, University of Duisburg-Essen, D-45141, Universitätsstr. 5, Germany.,Center for Water and Environmental Research, University of Duisburg-Essen, D-45141, Universitätsstr. 5, Germany
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4
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Akinyi MY, Jansen D, Habig B, Gesquiere LR, Alberts SC, Archie EA. Costs and drivers of helminth parasite infection in wild female baboons. J Anim Ecol 2019; 88:1029-1043. [PMID: 30972751 DOI: 10.1111/1365-2656.12994] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Accepted: 03/08/2019] [Indexed: 11/30/2022]
Abstract
Helminth parasites can have wide-ranging, detrimental effects on host reproduction and survival. These effects are best documented in humans and domestic animals, while only a few studies in wild mammals have identified both the forces that drive helminth infection risk and their costs to individual fitness. Working in a well-studied population of wild baboons (Papio cynocephalus) in the Amboseli ecosystem in Kenya, we pursued two goals, to (a) examine the costs of helminth infections in terms of female fertility and glucocorticoid hormone levels and (b) test how processes operating at multiple scales-from individual hosts to social groups and the population at large-work together to predict variation in female infection risk. To accomplish these goals, we measured helminth parasite burdens in 745 faecal samples collected over 5 years from 122 female baboons. We combine these data with detailed observations of host environments, social behaviours, hormone levels and interbirth intervals (IBIs). We found that helminths are costly to female fertility: females infected with more diverse parasite communities (i.e., higher parasite richness) exhibited longer IBIs than females infected by fewer parasite taxa. We also found that females exhibiting high Trichuris trichiura egg counts also had high glucocorticoid levels. Female infection risk was best predicted by factors at the host, social group and population level: females facing the highest risk were old, socially isolated, living in dry conditions and infected with other helminths. Our results provide an unusually holistic understanding of the factors that contribute to inter-individual differences in parasite infection, and they contribute to just a handful of studies linking helminths to host fitness in wild mammals.
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Affiliation(s)
- Mercy Y Akinyi
- Department of Biology, Duke University, Durham, North Carolina.,Institute of Primate Research, National Museums of Kenya, Nairobi, Kenya
| | - David Jansen
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana
| | - Bobby Habig
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana.,Department of Biology, Queens college, City University of New York, Flushing, New York
| | | | - Susan C Alberts
- Department of Biology, Duke University, Durham, North Carolina.,Institute of Primate Research, National Museums of Kenya, Nairobi, Kenya.,Department of Evolutionary Anthropology, Duke University, Durham, North Carolina
| | - Elizabeth A Archie
- Institute of Primate Research, National Museums of Kenya, Nairobi, Kenya.,Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana
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5
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Sures B, Nachev M, Grabner D. The Rhine as Hotspot of Parasite Invasions. PARASITOLOGY RESEARCH MONOGRAPHS 2019. [DOI: 10.1007/978-3-030-29061-0_19] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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6
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Endocrine and immune responses of larval amphibians to trematode exposure. Parasitol Res 2018; 118:275-288. [DOI: 10.1007/s00436-018-6154-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2018] [Accepted: 11/12/2018] [Indexed: 11/26/2022]
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7
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Silva AT, Midwood JD, Aarestrup K, Pottinger TG, Madsen SS, Cooke SJ. The Influence of Sex, Parasitism, and Ontogeny on the Physiological Response of European Eels (Anguilla anguilla) to an Abiotic Stressor. Physiol Biochem Zool 2018; 91:976-986. [PMID: 29894278 DOI: 10.1086/698689] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Migration of adult European eels (Anguilla anguilla) from freshwater feeding grounds to oceanic spawning grounds is an energetically demanding process and is accompanied by dramatic physiological and behavioral changes. Humans have altered the aquatic environment (e.g., dams) and made an inherently challenging migration even more difficult; human activity is regarded as the primary driver of the collapse in eel populations. The neuroendocrine stress response is central in coping with these challenging conditions, yet little is known about how various biotic factors such as sex, parasites, and ontogeny influence (singly and via interactions) the stress response of eels. In this study, mixed-effects and linear models were used to quantify the influence of sex, parasitism (Anguillicola crassus), life stage (yellow and silver eels), and silvering stage on the stress response of eels when exposed to a standardized handling stressor. The physiological response of eels to a standardized abiotic stressor (netting confinement in air) was quantified through measurements of blood glucose and plasma cortisol. The relationships between biotic factors and the activity of gill Na+/K+-ATPase was also examined. Analyses revealed that in some instances a biotic factor acted alone while in other cases several factors interacted to influence the stress response. Blood glucose concentrations increased after exposure to the standardized stressor and remained elevated after 4 h. Variation in plasma cortisol concentrations after exposure to the stressor were found to be time dependent, which was exacerbated by life stage and parasitism condition. Males and nonparasitized silver eels had the highest Na+/K+-ATPase activity. Silvering stage was strongly positively correlated with Na+/K+-ATPase activity in female eels. Collectively, these findings confirm that the factors mediating stress responsiveness in fish are complicated and that aspects of inherent biotic variation cannot be ignored.
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8
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Friant S, Ziegler TE, Goldberg TL. Changes in physiological stress and behaviour in semi-free-ranging red-capped mangabeys (Cercocebus torquatus) following antiparasitic treatment. Proc Biol Sci 2017; 283:rspb.2016.1201. [PMID: 27466454 DOI: 10.1098/rspb.2016.1201] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Accepted: 07/06/2016] [Indexed: 12/30/2022] Open
Abstract
Parasites are ubiquitous in wildlife populations, but physiological and behavioural responses of hosts to infection are difficult to measure. We experimentally treated semi-free-ranging red-capped mangabeys (Cercocebus torquatus) in Nigeria with antiparasitic drugs and examined subsequent changes in glucocorticoid production and individual behaviour. Because both parasites and stress impact energy balance and health, we measured (i) behavioural time re-allocation via activity budgets, (ii) social relationships (e.g. social connectivity and dominance hierarchy stability) and (iii) body condition. We collected triplicate faecal samples (n = 441) from 49 individuals prior to and following treatment. Cortisol levels fluctuated in parallel with parasite abundance. Elevations in cortisol, but not parasitism, were related to reduced body condition. Behaviour also shifted according to infection status, with uninfected individuals spending more time foraging and less time resting and vigilant compared with when they were infected. Time spent feeding, travelling or socializing did not differ between pre- and post-treatment time periods. Group cohesion, but not dominance stability, changed following treatment, suggesting parasite-induced social avoidance. Together, these findings show a coordinated response to infection that promotes host tolerance through stress and energy conservation, reduces transmission risk and increases protection when infected hosts are vulnerable.
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Affiliation(s)
- Sagan Friant
- Nelson Institute for Environmental Studies, University of Wisconsin--Madison, Madison, WI 53706, USA Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin--Madison, Madison, WI 53706, USA
| | - Toni E Ziegler
- Wisconsin National Primate Research Centre, University of Wisconsin--Madison, Madison, WI 53706, USA
| | - Tony L Goldberg
- Nelson Institute for Environmental Studies, University of Wisconsin--Madison, Madison, WI 53706, USA
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9
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Kullmann B, Adamek M, Steinhagen D, Thiel R. Anthropogenic spreading of anguillid herpesvirus 1 by stocking of infected farmed European eels, Anguilla anguilla (L.), in the Schlei fjord in northern Germany. JOURNAL OF FISH DISEASES 2017; 40:1695-1706. [PMID: 28452055 DOI: 10.1111/jfd.12637] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Revised: 02/23/2017] [Accepted: 02/23/2017] [Indexed: 06/07/2023]
Abstract
The Schlei fjord in northern Germany is the recipient water of a comprehensive eel, Anguilla anguilla (L.), stocking programme. Since 2015, stocked eels become alizarin red S marked, but to date no control mechanism is implemented in this stock enhancement measure to prevent anthropogenic spreading of diseases. Consequentially, it was possible that farmed stocking cohorts of 2015 and 2016 (in total ca. 1040 kg) were subsequently tested positive for anguillid herpesvirus 1 (AngHV 1). For this study, 100 eels [total length (TL) 24.3-72.9 cm, age ca. 1-6 years] were caught in 2016 and investigated with regard to AngHV 1 infection, parasite load (Anguillicoloides crassus) and body conditions. 68% of the eels were found to be virus positive while larger specimens were more often infected. In addition, a fitted generalized linear model (area under the curve = 0.741) demonstrated that an increase in individual TL is accompanied with an increased risk of clinically relevant virus loads. Anguillicoloides crassus turned out to be an important stressor for eels, because parasite and virus load revealed a significant positive correlation. The results of this study evidently show the urgent need of a disease containment strategy for eel stocking programmes.
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Affiliation(s)
- B Kullmann
- Center of Natural History, Zoological Museum, University of Hamburg, Hamburg, Germany
| | - M Adamek
- Fish Disease Research Unit, Institute for Parasitology, University of Veterinary Medicine Hannover, Hannover, Germany
| | - D Steinhagen
- Fish Disease Research Unit, Institute for Parasitology, University of Veterinary Medicine Hannover, Hannover, Germany
| | - R Thiel
- Center of Natural History, Zoological Museum, University of Hamburg, Hamburg, Germany
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10
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Rodríguez-Quiroga JJ, Otero-Rodiño C, Suárez P, Nieto TP, García Estévez JM, San Juan F, Soengas JL. Differential effects of exposure to parasites and bacteria on stress response in turbot Scophthalmus maximus simultaneously stressed by low water depth. JOURNAL OF FISH BIOLOGY 2017; 91:242-259. [PMID: 28516502 DOI: 10.1111/jfb.13338] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 04/21/2017] [Indexed: 06/07/2023]
Abstract
The stress response of turbot Scophthalmus maximus was evaluated in fish maintained 8 days under different water depths, normal (NWD, 30 cm depth, total water volume 40 l) or low (LWD, 5 cm depth, total water volume 10 l), in the additional presence of infection-infestation of two pathogens of this species. This was caused by intraperitoneal injection of sublethal doses of the bacterium Aeromonas salmonicida subsp. salmonicida or the parasite Philasterides dicentrarchi (Ciliophora:Scuticociliatida). The LWD conditions were stressful for fish, causing increased levels of cortisol in plasma, decreased levels of glycogen in liver and nicotinamide adenine dinucleotide phosphate (NADP) and increased activities of G6Pase and GSase. The presence of bacteria or parasites in fish under NWD resulted in increased cortisol levels in plasma whereas in liver, changes were of minor importance including decreased levels of lactate and GSase activity. The simultaneous presence of bacteria and parasites in fish under NWD resulted a sharp increase in the levels of cortisol in plasma and decreased levels of glucose. Decreased levels of glycogen and lactate and activities of GSase and glutathione reductase (GR), as well as increased activities of glucose-6-phosphate dehydrogenase (G6PDH), 6-phosphogluconate dehydrogenase (6PGDH) and levels of nicotinamide adenine dinucleotide phosphate (NADPH) occurred in the same fish in liver. Finally, the presence of pathogens in S. maximus under stressful conditions elicited by LWD resulted in synergistic actions of both type of stressors in cortisol levels. In liver, the presence of bacteria or parasites induced a synergistic action on several variables such as decreased activities of G6Pase and GSase as well as increased levels of NADP and NADPH and increased activities of GPase, G6PDH and 6PGDH.
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Affiliation(s)
- J J Rodríguez-Quiroga
- Laboratorio de Parasitoloxía, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Ciencias do Mar and ECIMAT, Universidade de Vigo, E-36310, Vigo, Spain
| | - C Otero-Rodiño
- Laboratorio de Fisioloxía Animal, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía and ECIMAT, Universidade de Vigo, E-36310, Vigo, Spain
| | - P Suárez
- Laboratorio de Bioquímica, Departamento de Bioquímica, Xenética e Inmunoloxía, Facultade de Ciencias do Mar and ECIMAT, Universidade de Vigo, E-36310, Vigo, Spain
| | - T P Nieto
- Laboratorio de Microbioloxía, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Ciencias do Mar and ECIMAT, Universidade de Vigo, E-36310, Vigo, Spain
| | - J M García Estévez
- Laboratorio de Parasitoloxía, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Ciencias do Mar and ECIMAT, Universidade de Vigo, E-36310, Vigo, Spain
| | - F San Juan
- Laboratorio de Bioquímica, Departamento de Bioquímica, Xenética e Inmunoloxía, Facultade de Ciencias do Mar and ECIMAT, Universidade de Vigo, E-36310, Vigo, Spain
| | - J L Soengas
- Laboratorio de Fisioloxía Animal, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía and ECIMAT, Universidade de Vigo, E-36310, Vigo, Spain
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11
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Arnott SA., Dyková I, Roumillat WA, de Buron I. Pathogenic endoparasites of the spotted seatrout, Cynoscion nebulosus: patterns of infection in estuaries of South Carolina, USA. Parasitol Res 2017; 116:1729-1743. [DOI: 10.1007/s00436-017-5449-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 04/12/2017] [Indexed: 01/10/2023]
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12
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Influence of nematode Anguillicoloides crassus infestation on the cellular and humoral innate immunity in European eel (Anguilla anguilla L.). Cent Eur J Immunol 2015; 40:127-31. [PMID: 26557024 PMCID: PMC4637385 DOI: 10.5114/ceji.2015.52824] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Accepted: 04/28/2015] [Indexed: 11/17/2022] Open
Abstract
Parasitic invasions are recognized as one of the primary factors responsible for decreasing populations of European eel. The aim of the present study was to determine the influence of infestation with the nematode Anguillicoloides crassus on the innate immunity in European eel (Anguilla anguilla). Anguillicoloides crassus parasitizes the swim bladder of this fish. Levels of the following immunological parameters were measured: spleen phagocyte respiratory burst activity, spleen phagocyte potential killing activity, pronephros lymphocyte proliferation stimulated by concanavaline A or lipopolisaccharide, plasma lysozyme and ceruloplasmin activity, total protein and immunoglobulin (Ig) serum levels. The analyses of the results of humoral and cellular immunity indicate that all studied parameters were statistically significant higher (p < 0.05) in non-infested fish compared to the ones with anguillicolosis except for ceruloplasmin level. These data suggest that the A. crassus infestation in European eel is responsible for a decreased immune response what could result in higher susceptibility to other pathogenic conditions.
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13
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Muñoz P, Peñalver J, Ruiz de Ybañez R, Garcia J. Influence of adult Anguillicoloides crassus load in European eels swimbladder on macrophage response. FISH & SHELLFISH IMMUNOLOGY 2015; 42:221-224. [PMID: 25463301 DOI: 10.1016/j.fsi.2014.11.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Revised: 11/06/2014] [Accepted: 11/12/2014] [Indexed: 06/04/2023]
Abstract
Anguillicoloides crassus has become one of the most important threats to the European eel (Anguilla anguilla). Adult parasites colonize the swimbladder leading to an impaired functioning of this organ. The infection is also responsible for an increased in the stress level of infected eels, that could produce an altered immune response as well. Differences in parasite loads and effects in the European and Japanese eel (Anguilla japonica) have been described. We have studied the influence of the number of adult parasites present in the swimbladder of wild eels on the macrophage response (phagocytosis and respiratory burst) as part of the first immune response to pathogens. Our results show an increased phagocytozed bacterial survival 24 h post-infection in macrophages of eels infected with more than ten adult parasites compared to macrophages from eels infected with less than those ten adult parasites. Respiratory burst results also showed a less efficient response in macrophages from eels infected with more than ten adult parasites, although in this case results were not found to be significant.
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Affiliation(s)
- P Muñoz
- Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad de Murcia, E-30100 Murcia, Spain; Campus de Excelencia Internacional Regional "Campus Mare Nostrum", Spain
| | - J Peñalver
- Campus de Excelencia Internacional Regional "Campus Mare Nostrum", Spain; Servicio de Pesca y Acuicultura, D.G. de Ganadería y Pesca, Consejería de Agricultura y Agua de la Región de Murcia, Juan XXIII, 30071 Murcia, Spain
| | - R Ruiz de Ybañez
- Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad de Murcia, E-30100 Murcia, Spain; Campus de Excelencia Internacional Regional "Campus Mare Nostrum", Spain
| | - J Garcia
- Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad Complutense de Madrid, Avda. Puerta de Hierro s/n, 28040 Madrid, Spain.
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14
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Effects of Anguillicola novaezelandiae on the levels of cortisol and hsp70 in the European eel. Parasitol Res 2014; 113:3817-22. [DOI: 10.1007/s00436-014-4049-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Accepted: 07/23/2014] [Indexed: 10/25/2022]
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15
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Peterson JD, Steffen JE, Reinert LK, Cobine PA, Appel A, Rollins-Smith L, Mendonça MT. Host stress response is important for the pathogenesis of the deadly amphibian disease, Chytridiomycosis, in Litoria caerulea. PLoS One 2013; 8:e62146. [PMID: 23630628 PMCID: PMC3632538 DOI: 10.1371/journal.pone.0062146] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2012] [Accepted: 03/18/2013] [Indexed: 02/05/2023] Open
Abstract
Chytridiomycosis, a disease caused by Batrachochytrium dendrobatidis, has contributed to worldwide amphibian population declines; however, the pathogenesis of this disease is still somewhat unclear. Previous studies suggest that infection disrupts cutaneous sodium transport, which leads to hyponatremia and cardiac failure. However, infection is also correlated with unexplained effects on appetite, skin shedding, and white blood cell profiles. Glucocorticoid hormones may be the biochemical connection between these disparate effects, because they regulate ion homeostasis and can also influence appetite, skin shedding, and white blood cells. During a laboratory outbreak of B. dendrobatidis in Australian Green Tree Frogs, Litoria caerulea, we compared frogs showing clinical signs of chytridiomycosis to infected frogs showing no signs of disease and determined that diseased frogs had elevated baseline corticosterone, decreased plasma sodium and potassium, and altered WBC profiles. Diseased frogs also showed evidence of poorer body condition and elevated metabolic rates compared with frogs showing no signs of disease. Prior to displaying signs of disease, we also observed changes in appetite, body mass, and the presence of shed skin associated with infected but not yet diseased frogs. Collectively, these results suggest that elevated baseline corticosterone is associated with chytridiomycosis and correlates with some of the deleterious effects observed during disease development.
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Affiliation(s)
- John D Peterson
- Department of Biological Sciences, Auburn University, Auburn, Alabama, United States of America.
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Lefebvre F, Fazio G, Mounaix B, Crivelli AJ. Is the continental life of the European eel Anguilla anguilla affected by the parasitic invader Anguillicoloides crassus? Proc Biol Sci 2013; 280:20122916. [PMID: 23325776 DOI: 10.1098/rspb.2012.2916] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Quantifying the fitness cost that parasites impose on wild hosts is a challenging task, because the epidemiological history of field-sampled hosts is often unknown. In this study, we used an internal marker of the parasite pressure on individual hosts to evaluate the costs of parasitism with respect to host body condition, size increase and reproductive potential of field-collected animals for which we also determined individual age. In our investigated system, the European eel Anguilla anguilla and the parasitic invader Anguillicoloides crassus, high virulence and severe impacts are expected because the host lacks an adaptive immune response. We demonstrated a nonlinear relationship between the severity of damage to the affected organ (i.e. the swimbladder, our internal marker) and parasite abundance and biomass, thus showing that the use of classical epidemiological parameters was not relevant here. Surprisingly, we found that the most severely affected eels (with damaged swimbladder) had greater body length and mass (+11% and +41%, respectively), than unaffected eels of same age. We discuss mechanisms that could explain this finding and other counterintuitive results in this host-parasite system, and highlight the likely importance of host panmixia in generating great inter-individual variability in growth potential and infection risk. Under that scenario, the most active foragers would not only have the greatest size increase, but also the highest probability of becoming repeatedly infected-via trophic parasite transmission-during their continental life.
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Affiliation(s)
- François Lefebvre
- Station Biologique de la Tour du Valat, Le Sambuc, 13200 Arles, France
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Quadroni S, Galassi S, Capoccioni F, Ciccotti E, Grandi G, De Leo GA, Bettinetti R. Contamination, parasitism and condition of Anguilla anguilla in three Italian stocks. ECOTOXICOLOGY (LONDON, ENGLAND) 2013; 22:94-108. [PMID: 23076840 DOI: 10.1007/s10646-012-1006-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 10/02/2012] [Indexed: 06/01/2023]
Abstract
In conjunction with habitat loss and overfishing, pollution and parasitism are believed to be relevant causes of collapse of Anguilla, as these can affect eel swimming ability and the development of gonads and embryos. The present study investigated Persistent Organic Pollutant (POP) concentrations, infection levels of Anguillicoloides crassus, lipid content and gonad abnormalities in eels sampled in 2007-2008 in three Italian water bodies (Caprolace Lake, Lesina Lagoon and Tevere River) that vary in salinity, trophic condition, contamination level and fishing pressure. Our analysis revealed that low-to-moderate levels of contamination and parasitism were not associated with gonad abnormalities in Caprolace Lake and Lesina Lagoon. On the contrary, POP concentrations and abundances of swim bladder nematodes were remarkably high in eels from the heavily urbanized Tevere River and were associated with significant gonad and swim bladder alterations. Contamination and infestation levels were so high to potentially impair spawner successful migration and reproduction. POP concentrations in Tevere eels also exceeded levels considered safe for food consumption. Though marginally contaminated, eels from the oligotrophic Caprolace Lake were in critical health condition: their lipid reserve was so low as to be considered insufficient to sustain the energetic costs of the transoceanic migration. Lesina eel stock was the only one displaying relatively good quality but here spawner abundance is likely limited by overfishing. Our results suggest that multiple stressors may potentially affect eel reproductive success. More definitive studies are needed to assess whether health effects caused by these multiple stressors are additive, compensatory or synergistic.
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Affiliation(s)
- Silvia Quadroni
- Department of Theoretical and Applied Sciences (Environmental Section), University of Insubria, Via Dunant 3, 21100, Varese, Italy.
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Yen Nhi TT, Mohd Shazili NA, Shaharom-Harrison F. Use of cestodes as indicator of heavy-metal pollution. Exp Parasitol 2012; 133:75-9. [PMID: 23146722 DOI: 10.1016/j.exppara.2012.10.014] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2012] [Revised: 09/18/2012] [Accepted: 10/19/2012] [Indexed: 11/30/2022]
Abstract
Thirty snakehead fish, Channa micropeltes (Cuvier, 1831) were collected at Lake Kenyir, Malaysia. Muscle, liver, intestine and kidney tissues were removed from each fish and the intestine was opened to reveal cestodes. In order to assess the concentration of heavy metal in the environment, samples of water in the surface layer and sediment were also collected. Tissues were digested and the concentrations of manganese (Mn), zinc (Zn), copper (Cu), cadmium (Cd) and lead (Pb) were analysed by using inductively-coupled plasma mass-spectrometry (ICP-MS) equipment. The results demonstrated that the cestode Senga parva (Fernando and Furtado, 1964) from fish hosts accumulated some heavy metals to a greater extent than the water and some fish tissues, but less than the sediment. In three (Pb, Zn and Mn) of the five elements measured, cestodes accumulated the highest metal concentrations, and in remaining two (Cu and Cd), the second highest metal accumulation was recorded in the cestodes when compared to host tissues. Therefore, the present study indicated that Senga parva accumulated metals and might have potential as a bioindicator of heavy-metal pollution.
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Affiliation(s)
- Tran Thi Yen Nhi
- Institute of Tropical Aquaculture, Universiti Malaysia Terengganu, 21030 Kuala Terengganu, Malaysia.
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Grabner DS, Dangel KC, Sures B. Merging species? Evidence for hybridization between the eel parasites Anguillicola crassus and A. novaezelandiae (Nematoda, Anguillicolidea). Parasit Vectors 2012; 5:244. [PMID: 23111012 PMCID: PMC3495632 DOI: 10.1186/1756-3305-5-244] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2012] [Accepted: 10/29/2012] [Indexed: 11/10/2022] Open
Abstract
Background The eel parasitic nematodes Anguillicola crassus (originating from Asia) and Anguillicola novaezelandiae (originating from New Zealand) were both introduced to Europe, but occurred in sympatry only in Lake Bracciano in Italy, where they both infected the European eel (Anguilla anguilla). A. novaezelandiae was introduced to the lake in 1975 and disappeared soon after A. crassus was also found there in 1993. We tested the hypothesis if hybridization of the two species might be an explanation for the findings at Lake Bracciano. Findings After laboratory infection of one European eel with 10 third stage larvae of each parasite, two living female and 4 male adults of each species were found to co-occur in the swim bladder after 222 days post exposure. In 9 out of 17 eggs, isolated in total from uteri of the two A. novaezelandiae females, alleles were detected by microsatellite analysis that are characteristic for A. crassus, suggesting the hybrid origin of these eggs. In contrast, none of the eggs isolated from A. crassus females possessed alleles different from those found in A. crassus adults, but it was revealed that one female can be inseminated by several males. Conclusion Our results show that A. crassus and A. novaezelandiae can co-infect a single eel and can mature together in the same swim bladder. We also provide evidence for the possibility of hybridization of A. crassus males with A. novaezelandiae females. Therefore, hybridization might be an explanation for the disappearance of A. novaezelandiae from Lake Bracciano.
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Affiliation(s)
- Daniel S Grabner
- University of Duisburg-Essen, Aquatic Ecology, Universitaetsstr, 5, Essen, 45141, Germany.
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Fazio G, Sasal P, Mouahid G, Lecomte-Finiger R, Moné H. Swim bladder nematodes (Anguillicoloides crassus) disturb silvering in European eels (Anguilla anguilla). J Parasitol 2012; 98:695-705. [PMID: 22404329 DOI: 10.1645/ge-2700.1] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
The introduced parasite Anguillicoloides crassus is thought to play an important role in the decline of freshwater eel (Anguilla spp.) populations. These nematodes are known to negatively affect many fitness-related traits in eels. We used experimental infections to study the effect of A. crassus on the relative size or mass of organs, and the expression of functionally relevant genes (total of 12 parameters) that are involved in the silvering process of Anguilla anguilla. Our results showed that the liver mass, the hemoglobin α-chain, and androgen receptors α expression levels were significantly higher in infected eels, whereas the freshwater rod opsin expression level and the gut mass were significantly lower in infected eels. Our results suggested that infected eels were at a more advanced stage in the silvering process than uninfected counterparts of similar size. These results may be explained by 2 hypotheses. First, A. crassus could trigger physiological mechanisms involved in the silvering process as a side-effect of infection. Second, eels may adjust their life history traits in response to infection. The implications for eel migration and reproductive success may be either negative or positive, depending on whether the response to A. crassus infection results in an additional cost of the parasite or is due to the phenotypic plasticity of the host.
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Affiliation(s)
- Géraldine Fazio
- CNRS-EPHE, USR 3278, CRIOBE, BP 1013, Papetoai, Moorea, Polynésie Française
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Bernies D, Brinker A, Daugschies A. An invasion record for the swimbladder nematode Anguillicoloides crassus in European eel Anguilla anguilla in a deep warm-monomictic [corrected] lake, from invasion to steady state. JOURNAL OF FISH BIOLOGY 2011; 79:726-746. [PMID: 21884109 DOI: 10.1111/j.1095-8649.2011.03054.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
This study is the first account of the establishment and development of the neozoic nematode parasite Anguillicoloides crassus in its host, the European eel Anguilla anguilla, in a deep, warm-monomictic [corrected] lake. A 21 year study of A. crassus took place in Upper Lake Constance (ULC), Europe's second largest pre-alpine lake. The study included two extensive surveys, one in 1991 during the initial parasite invasion phase and the second in 2006 when the infection was well established. The subtropical swimbladder nematode A. crassus was first recorded in A. anguilla in ULC in 1989. Prevalence reached 60% in 1992 and remained at this level until 2007. In 2008, prevalence decreased to 48%. Infection intensity peaked in 1993 at a mean value of 16 adult parasites per host fish. Around 90% of all A. anguilla examined displayed swimbladder lesions, with a significant trend to increasing severity over time. Moreover, heavy swimbladder lesions were seen in c. 10% of A. anguilla ready to migrate to their spawning habitat. Both ruffe Gymnocephalus cernuus and sunfish Lepomis gibbosus serve as paratenic hosts for A. crassus in ULC. Gymnocephalus cernuus seems to be the main vector, and infection is especially frequent in spring possibly caused by reduced immune system efficacy of G. cernuus during winter. In 1991, hypochromic anaemia was prevalent in ULC A. anguilla acutely infected with A. crassus, whereas in 2006 blood values were indicative of chronic infection. The growth and survival rates of A. anguilla during their continental phase were not noticeably altered in infected fish, but damage to the swimbladder probably impairs migration potential and thus the subsequent breeding success of the oceanic phase.
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Affiliation(s)
- D Bernies
- Fishery Research Station, Argenweg 50/1, 88085 Langenargen, Germany
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22
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Abdelmonem AA, Metwally MM, Hussein HS, Elsheikha HM. Gross and microscopic pathological changes associated with parasitic infection in European eel (Anguilla anguilla, Linnaeus 1758). Parasitol Res 2009; 106:463-9. [DOI: 10.1007/s00436-009-1688-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2008] [Accepted: 11/10/2009] [Indexed: 11/30/2022]
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Sjöberg NB, Petersson E, Wickström H, Hansson S. Effects of the swimbladder parasite Anguillicola crassus on the migration of European silver eels Anguilla anguilla in the Baltic Sea. JOURNAL OF FISH BIOLOGY 2009; 74:2158-2170. [PMID: 20735694 DOI: 10.1111/j.1095-8649.2009.02296.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
In a mark-recapture study in 2006, migrating European Anguilla anguilla silver eels were caught, tagged and released in the Baltic Sea and recaptures in commercial pound nets examined for possible effects on migration of infection with the swimbladder parasite Anguillicola crassus. The overall recapture rate was 36%. The prevalence of infection was lowest at the northernmost sampling site. There were no significant differences between infected and uninfected A. anguilla in condition indices, body fat content and estimated migration speeds. Parasite infection intensity levels were significantly negatively correlated with times and distances covered between release and recapture, but did not correlate with migration speed. It appears that more heavily infected A. anguilla were relatively more vulnerable to recapture in pound nets. It is hypothesized that parasite-induced damage to the swimbladder inhibited vertical migrations and infected A. anguilla tended to migrate in shallower coastal waters, relatively close to the shore.
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Affiliation(s)
- N B Sjöberg
- Swedish Board of Fisheries, Institute of Freshwater Research, Drottningholm, Sweden.
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24
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Trubiroha A, Wuertz S, Frank SN, Sures B, Kloas W. Expression of gonadotropin subunits in roach (Rutilus rutilus, Cyprinidae) infected with plerocercoids of the tapeworm Ligula intestinalis (Cestoda). Int J Parasitol 2009; 39:1465-73. [PMID: 19477180 DOI: 10.1016/j.ijpara.2009.05.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2009] [Revised: 04/27/2009] [Accepted: 05/07/2009] [Indexed: 11/29/2022]
Abstract
Plerocercoids of the tapeworm Ligula intestinalis (Cestoda: Bothriocephalidea) have been reported to inhibit gametogenesis of their intermediate fish hosts. However, mechanistic studies are rare and the proximate cues leading to impaired reproduction still remain unknown. In the present study we investigated the effects of infection by L. intestinalis on reproductive parameters of roach (Rutilus rutilus, Cyprinidae), a common fish host of this parasite. Field studies on roach demonstrated that in both genders infection prevented gonad development. As revealed by quantitative PCR, infection was accompanied by essentially lower pituitary expression of follicle-stimulating hormone beta-subunit (FSHbeta) and luteinizing hormone beta-subunit (LHbeta) mRNA compared with uninfected roach, providing clear evidence for gonadotropin-insufficiency as the cause of arrested gametogenesis. Under controlled laboratory conditions infected roach showed lower mRNA levels of FSHbeta but not of LHbeta, despite histology revealing similar gonad stages as in uninfected conspecifics. These findings indicate the involvement of FSH rather than LH in mediating effects of infection early during gonad development in roach. Moreover, the impact of L. intestinalis on reproductive parameters of roach appeared to be independent of the parasite burden. Together, these data provide valuable information on the role of FSH and LH as mediators of parasite-induced sterilization in a vertebrate and implicate the selective inhibition of host reproduction by L. intestinalis as a natural source of endocrine disruption in fish.
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Affiliation(s)
- Achim Trubiroha
- Department of Aquaculture and Ecophysiology, Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Müggelseedamm 310, D-12587 Berlin, Germany.
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25
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Knopf K, Krieger A, Hölker F. PARASITE COMMUNITY AND MORTALITY OF OVERWINTERING YOUNG-OF-THE-YEAR ROACH (RUTILUS RUTILUS). J Parasitol 2007; 93:985-91. [DOI: 10.1645/ge-951r1.1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Abstract
Although 63 and 55 species of helminths have been reported from each species of Atlantic eel and from 29 to 19 for each species of Pacific eel only the monogeneans Pseudodactylogyrus bini and P. anguillae and the nematode Anguillicola crassus, originally specific to species of Pacific eels, can be considered serious pathogens. None of the three are normally pathogenic to their preferred natural eel host species in the wild. Pseudodactylogyrus spp. only cause serious local gill damage when present on a host in large numbers under optimal conditions that facilitate transmission. This is the case in eel aquaculture, where infections can be controlled by drugs. Anguillicola crassus is only pathogenic to Anguilla anguilla and A. rostrata when Atlantic eels are introduced to the far east or when the parasites have been introduced to Europe. Here the parasite life cycle differs in that A. crassus can infect a wide range of intermediate hosts, employ paratenic hosts and survive as larvae for months in the swimbladder wall. This makes it an excellent colonizer. Its major pathogenic effects on eels result from haemorrhaging in, and thickening of, the swimbladder wall. It reduces the oxygen concentration in the swimbladder, reducing its ability to function as a hydrostatic organ, and increases the stress response of eels. In shallow lakes at warm temperatures this can result in mass mortalities. It is also feared that the parasite affects the ability of eels to migrate to the Sargasso Sea and so contributes to the decline in eel populations. Control by drug treatment is possible in culture, but not in the wild.
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Affiliation(s)
- C R Kennedy
- School of Biological Sciences, University of Exeter, Exeter, UK.
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27
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Sures B. How parasitism and pollution affect the physiological homeostasis of aquatic hosts. J Helminthol 2007; 80:151-7. [PMID: 16768858 DOI: 10.1079/joh2006346] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
AbstractParasitism poses a serious threat to hosts under certain circumstances, while the well-being of organisms is also negatively affected by environmental pollution. Little information is available on the simultaneous effects of parasites and pollutants on the physiological homeostasis of organisms. The present paper demonstrates that parasites: (i) may influence the metabolism of pollutants in infected hosts, (ii) interact with pollution in synergistic or antagonistic ways, and (iii) may induce physiological reactions in hosts which were thought to be pollutant-induced. Experimental studies on the uptake and accumulation of metals by fish reveal that fish infected with acanthocephalans have lower metal levels than uninfected hosts; e.g. Pomphorhynchus laevis reduces lead levels in fish bile, thereby diminishing or impeding the hepatic intestinal cycling of lead, which may reduce the quantity of metals available for fish. Alterations in pollutant uptake and accumulation in different intermediate and final hosts due to parasites are thus very important in the field of ecotoxicology. In addition to such alterations, there is a close interaction between the effects of pollutants and parasites which seems to be mediated at least partly by the endocrine system, which itself is closely related to the immune system in fish. Laboratory studies on eels experimentally infected with the swimbladder nematode Anguillicola crassus reveal that toxic chemicals such as polychlorinated biphenyls produce immunosuppressive effects which facilitate parasite infection. Similarly, an increase in serum cortisol concentration in eels due to chemical exposure and infection is correlated with decreasing levels of anti-A. crassus antibodies. Furthermore, parasites are able to elicit physiological changes which are attributed to chemicals with endocrine disrupting activity, e.g. the cestode Ligula intestinalis is known to suppress gonad development in roach. The most thoroughly documented examples of endocrine disruption in wild fish are in roach, and it is conceivable that this disruption is not only due to chemical activity but also to parasites such as L. intestinalis or species of the phylum Microspora.
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Affiliation(s)
- B Sures
- Zoologisches Institut I - Okologie/Parasitologie, Universität Karlsruhe, Kaiserstr. 12, Geb. 07.01, 76128 Karlsruhe, Germany.
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Abstract
AbstractOver the past decades, various free-living animals (hosts) and their parasites have invaded recipient areas in which they had not previously occurred, thus gaining the status of aliens or exotics. In general this happened to a low extent for hundreds of years. With variable frequency, invasions have been followed by the dispersal and establishment of non-indigenous species, whether host or parasite. In the literature thus far, colonizations by both hosts and parasites have not been treated and reviewed together, although both are usually interwoven in various ways. As to those factors permitting invasive success and colonization strength, various hypotheses have been put forward depending on the scientific background of respective authors and on the conspicuousness of certain invasions. Researchers who have tried to analyse characteristic developmental patterns, the speed of dispersal or the degree of genetic divergence in populations of alien species have come to different conclusions. Among parasitologists, the applied aspects of parasite invasions, such as the negative effects on economically important hosts, have long been at the centre of interest. In this contribution, invasions by hosts as well as parasites are considered comparatively, revealing many similarities and a few differences. Two helminths, the liver fluke,Fasciola hepatica,of cattle and sheep and the swimbladder nematode,Anguillicola crassus,of eels are shown to be useful as model parasites for the study of animal invasions and environmental global change. Introductions ofF. hepaticahave been associated with imports of cattle or other grazing animals. In various target areas, susceptible lymnaeid snails serving as intermediate hosts were either naturally present and/or were introduced from the donor continent of the parasite (Europe) and/or from other regions which were not within the original range of the parasite, partly reflecting progressive stages of a global biota change. In several introduced areas,F. hepaticaco-occurs with native or exotic populations of the congenericF. gigantica, with thus far unknown implications. Over the fluke's extended range, in addition to domestic stock animals, wild native or naturalized mammals can also serve as final hosts. Indigenous and displaced populations ofF. hepatica, however, have not yet been studied comparatively from an evolutionary perspective.A. crassus, from the Far East, has invaded three continents, without the previous naturalization of its natural hostAnguilla japonica, by switching to the respective indigenous eel species. Local entomostrac crustaceans serve as susceptible intermediate hosts. The novel final hosts turned out to be naive in respect to the introduced nematode with far reaching consequences for the parasite's morphology (size), abundance and pathogenicity. Comparative infection experiments with Japanese and European eels yielded many differences in the hosts' immune defence, mirroring coevolution versus an abrupt host switch associated with the introduction of the helminth. In other associations of native hosts and invasive parasites, the elevated pathogenicity of the parasite seems to result from other deficiencies such as a lack of anti-parasitic behaviour of the naïve host compared to the donor host which displays distinct behavioural patterns, keeping the abundance of the parasite low. From the small amount of available literature, it can be concluded that the adaptation of certain populations of the novel host to the alien parasite takes several decades to a century or more. Summarizing all we know about hosts and parasites as aliens, tentative patterns and principles can be figured out, but individual case studies teach us that generalizations should be avoided.
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Affiliation(s)
- H Taraschewski
- Zoologisches Institut I, Okologie-Parasitologie, Universität Karlsruhe, Kornblumenstrasse 13, 76128 Karlsruhe, Germany.
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Interaction between the severity of the infection by the nematode Anguillicola crassus and the tolerance to hypoxia in the European eel Anguilla anguilla. Acta Parasitol 2007. [DOI: 10.2478/s11686-007-0013-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
AbstractAn experiment was conducted to test the effect of the infection by the swimbladder nematode Anguillicola crassus on the survival of the European eel Anguilla anguilla when exposed to hypoxic conditions. Forty-four wild caught and naturally infected eels were placed in an aquarium filled with water from the fishing site (Vaccarès Lagoon, French Mediterranean coast). In this confined environment (271), under decreasing oxygen resources, the first eel death occurred after 45 h (O2 = 0.98 mg l−1) and the last one after 96 h (O2 = 0.48 mg l−1). After dissection and parasite examination, analyses revealed significant negative correlations between the time to death and various parameters of parasite pressure (e.g., number of lumen worms, parasite mass, health state of the infected organ). It was shown that the severity of damage to the swimbladder rather than the count of living parasites was the major contributing factor in explaining the variation in time to death. These semi-experimental data demonstrating an increased eel mortality rate under severe oxygen stress are discussed for their relevance under field conditions, especially during hot summer months.
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Vettier A, Sébert P. Pressure resistance of aerobic metabolism in eels from different water environments. Mitochondrion 2005; 3:347-54. [PMID: 16120366 DOI: 10.1016/j.mito.2004.02.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2003] [Revised: 02/04/2004] [Accepted: 02/18/2004] [Indexed: 11/30/2022]
Abstract
Eels from different locations were tested comparing their energetic capacities to migrate by studying muscle (red and white) aerobic metabolism. As the migratory activity corresponds to a lengthy swimming activity at depth, their pressure resistance was evaluated by considering fish response to compression, mitochondrial respiration measured under pressure (101 ATA) and cytochrome c oxidase after 3 days under pressure. The results show that only fish from two of the sites have the metabolic capacities to cope with the high pressure encountered during migration.
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Affiliation(s)
- Aurélie Vettier
- Unité Haute Pression et Métabolisme (UHPM), Laboratoire de Physiologie, UFR Médecine, EA 2217, 22, Avenue C. Desmoulins, CS 93837, 29238 Brest Cedex, France.
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31
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Sures B, Lutz I, Kloas W. Effects of infection with Anguillicola crassus and simultaneous exposure with Cd and 3,3′,4,4′,5-pentachlorobiphenyl (PCB 126) on the levels of cortisol and glucose in European eel ( Anguilla anguilla ). Parasitology 2005; 132:281-8. [PMID: 16209723 DOI: 10.1017/s0031182005009017] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2005] [Revised: 08/24/2005] [Accepted: 08/24/2005] [Indexed: 11/07/2022]
Abstract
To investigate whether the stress response of European eels infected with Anguillicola crassus is influenced by environmental pollutants, experimentally infected eels were exposed to Cd and/or to 3,3', 4,4', 5-pentachlorobiphenyl (PCB 126). Serum cortisol and glucose concentrations of these eels were monitored over a period of 103 days and were compared with data from infected, unexposed eels as well as with data from uninfected eels. Additionally, the levels of cortisol were correlated with concentrations of Anguillicola-specific antibodies. All eels showed an initial increase of the cortisol levels until day 63. This general elevation of plasma cortisol is most likely due to handling stress, as all eels were repeatedly netted and afterwards inoculated with a feeding tube. At the end of the exposure period eels which were infected and those which were infected and simultaneously exposed to Cd and PCB showed significantly higher levels than the controls. The general course of serum glucose levels in eels resembled that of cortisol. Accordingly, Spearman correlation analysis revealed that an increase in serum cortisol concentrations is correlated with rising levels of glucose. With respect to immune-endocrine interactions a significant negative correlation between cortisol and anti-A. crassus antibodies was found. Our data show that A. crassus is the most potent stressor for European eels among the treatments tested within this study. This is important in terms of ecotoxicological studies as the main effects are caused by parasites rather than chemicals. Accordingly, effects of parasites on the physiological homeostasis of organisms must be considered in ecotoxicology. From the parasitological point of view our results suggest that probably as part of an unbalanced host-parasite interaction A. crassus evokes a strong cortisol response in A. anguilla, thereby suppressing the immune response which in turn enables the parasite to establish. The parasite-induced stress response in the newly adopted European eel might be one of the factors which contributes to the extremely effective colonizing strategy of A. crassus.
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Affiliation(s)
- B Sures
- Zoologisches Institut I - Okologie/Parasitologie, Universität Karlsruhe, Geb. 07.01, Kornblumenstrasse 13, D76128, Karlsruhe, Germany.
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Gollock MJ, Kennedy CR, Brown JA. European eels, Anguilla anguilla (L.), infected with Anguillicola crassus exhibit a more pronounced stress response to severe hypoxia than uninfected eels. JOURNAL OF FISH DISEASES 2005; 28:429-36. [PMID: 16083448 DOI: 10.1111/j.1365-2761.2005.00649.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
The parasite, Anguillicola crassus is a non-native species that infects naive European eels, Anguilla anguilla, and causes pathological damage to the swimbladder, potentially compromising their ability to cope with hypoxic conditions. This study aimed to elucidate whether anguillicolosis exacerbates the stress responses to exposure to hypoxic water, conditions that have been implicated in mass mortalities of wild infected European eels. Blood parameters in infected and uninfected eels were measured during exposure to severe hypoxia over an 8-h period. Infected fish showed significantly higher levels of plasma cortisol compared with uninfected eels after 4 h of hypoxia. Uninfected fish showed an almost twofold increase in plasma glucose after 8-h exposure to hypoxia but infected fish showed no significant change, so that the plasma glucose concentration was significantly higher in uninfected eels than in infected eels. Both groups showed similar elevations in blood haematocrit, suggesting a similar catecholamine response in infected and uninfected eels. The lack of a hyperglycaemic response in infected eels, despite indirect evidence of a catecholamine response to hypoxia, may reflect an increase in glucose turnover. The data suggest that anguillicolosis results in a significantly greater corticosteroid stress response to hypoxia accompanied by a higher metabolic cost.
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Affiliation(s)
- M J Gollock
- Hatherly Laboratories, School of Biological Sciences, University of Exeter, Exeter, UK.
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Klar B, Sures B. A nonlinear model of stress hormone levels in rats-the interaction between pollution and parasites. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2004; 59:23-30. [PMID: 15261719 DOI: 10.1016/s0147-6513(03)00100-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2003] [Revised: 05/27/2003] [Accepted: 06/02/2003] [Indexed: 05/24/2023]
Abstract
The impact of an infection with a parasite and a simultaneous cadmium exposure on the stress hormone levels of rats was studied. To this end, we introduce a nonlinear heteroscedastic model, which is able to describe the temporal evolution of cortisol concentrations in groups of rats treated by cadmium or parasite infection. A thorough analysis gives strong evidence that parasitic infection and cadmium exposure affect the stress hormone level of rats in an additive manner. Therefore, the host's response to environmental pollution should be studied in relation to parasite infections.
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Affiliation(s)
- B Klar
- Institut für Mathematische Stochastik, Universität Karlsruhe, Englerstr. 2, Karlsruhe 76128, Germany
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Sures B, Siddall R. Pomphorhynchus laevis (Palaeacanthocephala) in the intestine of chub (Leuciscus cephalus) as an indicator of metal pollution. Int J Parasitol 2003; 33:65-70. [PMID: 12547347 DOI: 10.1016/s0020-7519(02)00249-7] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Chub experimentally infected with the acanthocephalan parasite Pomphorhynchus laevis were exposed to 0.01 mg l(-1) Pb(2+) over 5 weeks. Lead was rapidly accumulated in the intestinal worms reaching a steady-state concentration after 4 weeks. This concentration was significantly greater than in the host muscle, liver and intestine and more than 9,000 times higher than the exposure concentration. Lead accumulation in P. laevis increased at a higher exposure concentration but was not correlated with either parasite intensity or with pooled or individual worm weight. The highest lead concentrations were recorded in those specimen of P. laevis that were attached in the posterior intestine. Interestingly, parasitised chub accumulated less lead in their own tissues than uninfected conspecifics. A mechanism of lead uptake by P. laevis and the application of acanthocephalans as accumulation indicators of metal pollution is discussed.
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Affiliation(s)
- Bernd Sures
- Zoologisches Institut I - Okologie/Parasitologie, Universität Karlsruhe, Geb. 07.01, Kornblumenstrasse 13, Germany.
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Sures B, Scheef G, Klar B, Kloas W, Taraschewski H. Interaction between cadmium exposure and infection with the intestinal parasite Moniliformis moniliformis (Acanthocephala) on the stress hormone levels in rats. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2002; 119:333-340. [PMID: 12166667 DOI: 10.1016/s0269-7491(01)00340-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The impact of an infection with the acanthocephalan Moniliformis moniliformis and a simultaneous Cd-exposure on the stress hormone levels of rats was studied. Immediately after the application of cadmium to some rats, cortisol levels in all groups of rats, as quantified by radioimmunoassay (RIA), significantly increased. However, infections with M. moniliformis as well as the uptake of Cd reduced significantly the cortisol release compared to untreated controls. While catecholamine concentrations, as determined by high-performance liquid chromatography (HPLC), showed no clear tendency during the experimental period, the ratio of C(adrenaline)/C(noradrenaline) in the controls showed the significantly lowest value of all four groups after killing the animals. Thus, the acanthocephalan infection as well as the Cd-exposure and the combination of both treatments affect hormone homeostasis in the rats which probably lead to negative effects on the health of the rat. Therefore parasite infections must be carefully considered in environmental impact studies, as an important factor affecting the host's health.
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Affiliation(s)
- B Sures
- Zoologisches Institut I-Okologie/Parasitologie, Universität Karlsruhe, Germany.
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