Parasites of unionid molluscs (Bivalvia, Unionidae) and their effect on the body of molluscs
AbstractAmong the molluscs of the family Unionidae extensivity of infestation by the helminth Aspidogaster conchicola (Trematoda, Aspidogastridae) is the highest in Unio tumidus and Anodonta anatina, and the lowest – in U. pictorum. The mites of the genus Unionicola (Arachnida, Unionicolidae) occur more often in species of the genus Anodonta and Pseudanodonta complanata than in species of Unio. The larvae of trematodes Bucephalus polymorphus (Trematoda, Bucephalidae) are more often identified in species of the genus Anodonta. The intensity of invasion of molluscs by the helminth A. conchicola was 1.0–5.6 ind./ind. (Unio – 1.0–3.3, Pseudanodonta – 3.0–5.6, Anodonta – 1.3–4.0 ind.), by the water mites Unionicola – 1–69 ind./ind. (Unio, Pseudanodonta – 1–11, Anodonta – 1–69). Due to the influence of aspidogastreans, the cytoplasmic vacuolization and hypertrophy of the cells of the pericardial epithelium and the layer of connective tissue was observed, which leads to a shrinkage of the upper side of the pericardium. Often, there was a nuclear pyknosis and, with deeper violations, their karyorrhexis and karyolysis. In the layer of connective tissue of pericardium of A. anatina encapsulated larvae of aspidogastereans were found. An increase in the cardiac index was observed in molluscs infested by aspidogastreans: the change in the index was the smallest in U. crassus (at 11.5%) and the largest in U. tumidus (at 54.1–61.0%). Smaller cardiac indexes are typical for molluscs with a lower intensity of infestation by aspidogastreans. Moderate intensity of infestation by this helminth (6–10 ind./ind.) caused an increase in the heart rate in molluscs (18.6–29.6%), high intensity (>10 ind./ind.) caused the decreasing of this indicator (14.5–24.0%). At low intensity of the mite (up to 20 individuals) and invasion of the trematode B. polymorphus (minor infections; part of the reproductive glands, populated by parasites, is less than 50%) the acceleration of ciliary beating and increasing of the duration of ciliary beating of the ciliated epithelium (1.4–2.6 times) were observed in species Anodonta and U. pictorum, at high intensity of invasion the inhibition of beating and reduction of the duration of ciliary beating of the ciliated epithelium in these species (45.9–57.4%) was observed. In the case of the general pathological process in the body of molluscs , the influence of parasites can cause the elimination of individuals with high intensity of infestation , which affects the absolute number and population density of molluscs.
Allam, B., & Raftos, D. (2015). Immune responses to infectious diseases in bivalves. Journal of Invertebrate Pathology, 131, 121–136.
Alyakrinskaya, I. O. (1989). O serdechnom indekse nekotoryh Gastropoda (Mollusca) [Heart index in some Gastropoda (Mollusca)]. Jekologija, 1, 79–82 (in Russian).
Baker, R. A. (1976). Tissue damage and leukocytic infiltration following attachment of the mite Unionicola intermedia to the gills of the bivalve mollusc Anodonta anatina. Journal of Invertebrate Pathology, 27(3), 371–376.
Baker, R. A. (1977). Nutrition of the mite Unionicola intermedia, Koenike and its relationship to the inflammatory response induced in its molluscan host Anodonta anatina, L. Parasitology, 75(3), 301–308.
Chernogorenko, M. I. (1983) Lichinki trematod v mollyuskah Dnepra i ego vodohranilishch (fauna, biologiya, zakonomernosti formirovaniya) [The trematode larvae of mollusks of Dnipro River and its reservoirs (fauna, biology, regularities of formation)]. Naukova Dumka, Kyiv (in Russian).
Choo, J., & Taskinen, J. (2015). Effect of short-term temperature change on cercarial release by Rhipidocotyle fennica (Trematoda, Bucephalidae) from the freshwater bivalve host, Anodonta anatina. Ecological Parasitology and Immunology, 4, art235932.
Cichy, A., Urbańska, M., Marszewska, A., Andrzejewski, W., & Żbikowska, E. (2016). The invasive Chinese pond mussel Sinanodonta woodiana (Lea, 1834) as a host for native symbionts in European waters. Journal of Limnology, 75(2), 288–296.
Giese, A. C., Hart, M. A., Smith, A. M., & Cheung, M. A. (1967). Seasolal changes in body component indices and chemical composition in the pismo clam Tivela stultorum. Comparative Biochemistry and Physiology, 22(2), 549–561.
Glöer, P., & Meier-Brook, С. (1998). Süsswassermollusken. DJN, Hamburg.
Huehner, M. K., & Etges, F. J. (1981). Encapsulation of Aspidogaster conchicola (Trematoda: Aspidogastrea) by unionid mussels. Journal of Invertebrate Pathology, 37(2), 123–128.
Jokela, J., Taskinen, J., Mutikainen, P., & Kopp, K. (2005). Virulence of parasites in hosts under environmental stress: Experiments with anoxia and starvation. Oikos, 108, 156–164.
Jokela, J., Uotila, L., & Taskinen, J. (1993). Effect of the castrating trematode parasite Rhipidocotyle fennica on energy allocation of fresh-water clam Anodonta piscinalis. Functional Ecology, 7(3), 332–338.
Marszewska, A., & Cichy, A. (2015). Unionid clams and the zebra mussels on their shells (Bivalvia: Unionidae, Dreissenidae) as hosts for trematodes in lakes of the Polish lowland. Folia Malacologica, 23, 149–154.
McElwain, A., Fleming, R., Lajoie, M., Maney, C., Springall, B., & Bullard, S. A. (2016). Pathological changes associated with eggs and larvae of Unionicola sp. (Acari: Unionicolidae) infecting Strophitus connasaugaensis (Bivalvia: Unionidae) from Alabama Creeks. Journal of Parasitology, 102(1), 75–86.
Müller, T., Czarnoleski, M., Labecka, A. M., Cichy, A., Zając, K., & Dragosz-Kluska, D. (2015). Factors affecting trematode infection rates in freshwater mussels. Hydrobiologia, 742(1), 59–70.
Pauley, G. B., & Becker, C. D. (1968). Aspidogaster conchicola in Mollusks of the columbia river system with comments on the host’s pathological response. Journal of Parasitology, 54(5), 917–920.
Taskinen, J. (1998). Influence of trematode parasitism on the growth of a bivalve host in the field. International Journal for Parasitology, 28(4), 599–602.
Taskinen, J., & Valtonen, E. T. (1995). Age-, size-, and sex-specific infection of Anodonta piscinalis (Bivalvia: Unionidae) with Rhipidocotyle fennica (Digenea: Bucephalidae) and its influence on host reproduction. Canadian Journal of Zoology, 73(5), 887–897.
Taskinen, J., Valtonen, E. T., & Mäkelä, T. (1994). Quantity of sporocysts and seasonality of two Rhipidocotyle species (Digenea: Bucephalidae) in Anodonta piscinalis (Mollusca: Bivalvia). International Journal for Parasitology, 24, 877–886.
Yurishinets, V. I. (2010). Symbiotic organisms of some alien species of freshwater fishes and mollusks of water bodies of the Danube River and Dnieper River basins. Russian Journal of Biological Invasions, 1(2), 149–152.
Yuryshynets, V., & Krasutska, N. (2009). Records of the parasitic worm Aspidogaster conchicola (Baer 1827) in the Chinese pond mussel Sinanodonta woodiana (Lea 1834) in Poland and Ukraine. Aquatic Invasions, 4, 491–494.
Zdun, V. I. (1961). Lychynky trematod v prisnovodnyh molyuskah Ukrayiny [Trematod larvae in freshwater mollusks of Ukraine]. AN URSR, Kyiv (in Ukrainian).
Zhadin, V. I. (1926). Nashi presnovodnye mollyuski [Our freshwater mollusks]. Izdatel’stvovo Okskoj Biologicheskoj Stancii, Murom (in Russian).
Zhan, X., Li, C., & Wu, H. (2017). Trematode Aspidogastrea found in the freshwater mussels in the Yangtze River basin. Nutricion Hospitalaria, 34, 460–462.
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