Helminths of European smelt Osmerus eperlanus (Linnaeus, 1758) in Lake Hańcza and the Vistula Lagoon, with special regard to their zoonotic threats

Abstract

Reports published in recent years on the increased risk in the Baltic Sea of fish infection with larvae of nematodes potentially pathogenic to humans have prompted a study of European smelt Osmerus eperlanus with respect to the presence of these parasites in the Vistula Lagoon. Additionally, samples of this fish from Lake Hańcza were comparatively considered. The body cavity, the surface of internal organs, the alimentary tract and the swimbladder of fish from two environmentally different water bodies were taken into account in the analysis. Only the tapeworm Proteocephalus longicollis was found in the alimentary tract of the fish from Lake Hańcza. Depending on the period of study, the prevalence ranged from 60% to 100%, and the mean intensity from 11.5 to 42.0. The helminth fauna of smelt from the Vistula Lagoon was more diverse: Cystidicola farionis occurred with a prevalence from 25.9 to 75.0% and a mean intensity of infection from 2.7 to 66.0%, Proteocephalus longicollis and cystacanths of Corynosoma with a prevalence ranging in different years from 12.0 to 44.0% and from 14.8 to 50.0%, respectively. Zoonotic parasites, such as nematode larvae of the Anisakidae family (Contracaecum sp., Anisakis simplex), occurred in the intestine with a prevalence of 31%, 72% and 22% in consecutive years of the study.

First Record of Contracaecum rudolphii Hartwich, 1964 in Carassius gibelio (Bloch, 1782) From Turkey

“…To date, another taxon, Contracaecum microcephalum was recorded for the Prussian carp from Srebarna Nature Reserve, Bulgaria (Shukerova, 2005). Different pervalence values of Contracaecum infection were reported from fish species (Stoyanov, Mutafchiev, Pankov, & Georgiev, 2017;Oztürk & Yesil, 2018;Dziekońska-Rynko, Mierzejewska, Kubiak, Rydzewska, & Hliwa, 2018;Chunchukova & Kirin, 2018;Sokolova et al, 2018). Low values of prevalence for Contracaecum infection in fish host in the present research are consistent with other studies (Mancini et al, 2008;Roumbedakis et al, 2013;Stoyanov et al, 2017).…”

Cystidicola farionis, a Swim Bladder Parasite of European Smelt: Characterization of the Nematode Trehalose Strategy

“…For this reason, the spread of parasitic infections due to fish movement is a major problem for fish living in artificial and natural water reservoirs, as well as for public health [ 23 ]. There are no reports on the pathogenicity of C. farionis to other animals or to humans [ 24 ]. However, a negative relationship between C. farionis prevalence and palmitoleic acid concentrations in wild lake whitefish ( Coregonus clupeaformis ) has been found, suggesting a decrease in the nutritional status of infested fish [ 25 ].…”

“…It is important to study the metabolism of the C. farionis parasite in order to learn about its survival strategy in the host because the prevalence of C. farionis in harvested catches in the Vistula Lagoon is high and ranges from 25.9% to 75% [ 24 ]. A high intensity of infection can cause fish anemia and inflammation of the swim bladder, worsening its hydrostatic and respiratory function.…”