Diphyllobothrium sp. and Other Parasites of Migrating and Rare Fish Species in the Southern Baltic Sea and Coastal Waters, Poland
by
,
Izabella Rząd
1,*
,
Beata Więcaszek
2,
Angelika Linowska
2,
Agata Korzelecka-Orkisz
2 and
Ewa Dzika
3 1
Institute of Marine and Environmental Sciences, University of Szczecin, Wąska 13, 71-415 Szczecin, Poland
2
Department of Hydrobiology, Ichthyology and Reproductive Biotechnology, West Pomeranian University of Technology in Szczecin, Kazimierza Królewicza 4, 71-550 Szczecin, Poland
3
Department of Medical Biology, School of Public Health, University of Warmia and Mazury in Olsztyn, Zołnierska 14c, 10-561 Olsztyn, Poland
*
Author to whom correspondence should be addressed.
Animals 2024, 14(7), 1029; https://doi.org/10.3390/ani14071029
Submission received: 5 February 2024
/
Revised: 25 March 2024
/
Accepted: 25 March 2024
/
Published: 28 March 2024
(This article belongs to the Collection Diagnosis, Evaluation, and Management of Wildlife, Exotic and Zoo Animals Disease)
Simple Summary
The aim of this study was to determine the occurrence of parasites in migrating and rare fish in the Pomeranian Bay and the Szczecin Lagoon and to determine the composition of the diet of these fish. The fish for analysis, i.e., saithe, European hake, dab, common sole, whiting, tub gurnard, surmullet, Atlantic mackerel, brill, and plaice, were obtained in the years 2010–2019. This study is the first to analyse the parasite fauna of sole, dab, hake, whiting, and plaice in the Pomeranian Bay, as well as saithe from the Szczecin Lagoon (Poland). The presence of parasites was confirmed: two species of protozoa; the larva of the tapeworm Diphyllobothrium sp.; seven species of nematodes, including the typical marine nematode Capillaria (Procapillaria) gracilis, rarely recorded in Poland; and one acanthocephalan. Analysis of the contents of the stomach and intestines showed that most of the fish had empty stomachs. Because the fish species analysed in the study are not typically present in the Baltic and we do not know how long they feed while they are in the Baltic, we cannot be certain which parasites they acquired in the water bodies analysed in the study and which were introduced during the migration of the fish. The round goby, an invasive fish species, was recorded for the first time in the diet of sole, and the freshwater tench was recorded for the first time in the diet of saithe.
Abstract
The present study is the first to analyse the parasite fauna of sole Solea solea, dab Limanda limanda, hake Merluccius merluccius, whiting Merlangius merlangus, and plaice Pleuronectes platessa in the Pomeranian Bay, as well as saithe Pollachius virens from the Szczecin Lagoon (Poland). The aim of this study was to determine the occurrence of parasites in migrating and rare fish in the Pomeranian Bay and the Szczecin Lagoon and to determine the composition of the diet of these fish. The fish for analysis were obtained in the years 2010–2019. The typical marine nematode Capillaria (Procapillaria) gracilis, rarely recorded in Poland, was found, in addition to the following parasites: Ichthyophonus hoferi, Trichodina jadranica, Diphyllobothrium sp., Dichelyne (Cucullanellus) minutus, Raphidascaris acus, Anisakis simplex, Contracaecum osculatum, Hysterothylacium aduncum, Pseudoterranova decipiens, and Echinorhynchus gadi. Because the fish species analysed in the study are not typically present in the Baltic (with the exception of plaice), and because we do not know how long they feed while they are in the Baltic, we cannot be certain which parasites they acquired in the water bodies analysed in the study and which were introduced during the migration of fish. Although these fish are outside of their normal geographic range (except for plaice), in the new environment, there were enough suitable intermediate hosts for the parasites of these fish to complete their life cycle and survive.
Keywords:
Baltic Sea; Diphyllobothrium; fish; parasites; one health
