“Changes in the helminth fauna and diet of the garfish, Belone belone, from the southern Baltic Sea (6853)”

Changes in the helminth fauna and diet of the garfish, Belone belone, from the southern Baltic Sea

The garfish Belone belone is a pelagic oceanodromous fish found in brackish and marine waters in the eastern North Atlantic Ocean and adjacent seas. In the Polish waters of the southern Baltic Sea, fish occur especially in Puck Bay. In this area, garfish is a species that is eagerly caught during its occurrence. It is observed in the coastal zone between April and June, during spawning migration. Since 2015, the importance of fish in local fishing has been observed.Knowledge related to the parasite fauna and food composition of that fish is scarce. Diet might not only be a source of nutrients but also might be an important source of fish infection.

Our studies aimed to describe the changes in the helminth fauna and diet of the garfish from the southern Baltic Sea.

The research material was collected in 2025. Standard analyses of fish were conducted, and the viscera of the fish were frozen for further analysis. The parasitological analysis of the liver (after digestion in artificial digestive juice) and the digestive tract was performed. All found parasites were collected and identified based on anatomo-morphological features. The stomach’s diet composition analysis was performed, and all found organisms were identified to the lowest possible level, depending on the level of decomposition.

In a previous study in 2015, the prevalence of parasitological infection was 24,59%. In the intestines, the most abundant were: nematode parasite Hysterothylacium sp. and tapeworm Schistocephalus solidus. The prevalence of Anisakis simplex larvae in the liver was 13,11%. The dominant element of the diet was three-spined stickleback (Gasterosteus aculeatus), present in 54,17% of fish with filled stomachs.

Recently obtained results were compared with the studies conducted in that area a decade ago to analyse the temporal changes in the parasite fauna and diet of garfish. Furthermore, it was analysed whether food elements could be the source of infection.

The project is funded by the Polish Ministry of Agriculture and Rural Development.

1. Pawlak, Joanna, NATIONAL MARINE FISHERIES RESEARCH INSTITUTE, GDYNIA, POLAND, Presenter
2. Nadolna-Ałtyn, Katarzyna, NATIONAL MARINE FISHERIES RESEARCH INSTITUTE, GDYNIA, POLAND, Author