Distribution of fish apophalosis in the river basins of Sumy region

Abstract

The causative agent of apophalosis (rosicotremosis) is the larva of Apofalus donicus. It is localized in the skin, scales, perch fins, rust, walleye, and some carp fishes that live in rivers flowing into the Black Sea, in the Tisza River, and in the Azov Sea estuaries. Mature trematode parasites in the small intestine the dogs, cats, foxes, some fish-eating birds (common buzzards, quarks, white storks) and humans. The purpose of the research was to conduct research to determine the incidence of fish for trematodoses and to develop measures to ensure the regimes of fish disinfection when they are detected. The research was conducted on the basis of the department of veterinary medicine, microbiology, zooghygiene and safety and quality of animal products of the Faculty of Veterinary Medicine of Sumy National Agrarian University. During the period 2018–2019, fish were caught from the rivers of the Dnieper Basin: Sula, Psla and Vorskla. The main species of fish studied are: carp – Cyprinus carpio (L.), perch – Perca fluviatilis (L.); common ruff (Gymnocephalus cernua), walleye (Sander iucioperca). A total of 321 fish were examined. Parasitological examination of the fish was carried out by the method of complete parasitological dissection, which makes it possible to conduct quantitative and qualitative accounting of all helminths affected by the fish. The autopsy of the fish was performed according to the conventional method. The incision was made from the anal fin up and forward to the gill lid just above the base of the pectoral fin. As a result of the fish studies, the larvae of trematodes were identified, which by structure were classified as Apofalus donicus. The larvae were alive, localized under the skin and moved. The overall invasion intensity for all species of fish studied was 3.64%. In the next phase of the study we conducted experiments to determine the resistance of the larvae to different modes of freezing, salinization and heat treatment. effective for decontamination of fish meat with the presence of metacercariae are: boiling at 80 °C, 15 minutes, at 100 °C, 10 minutes; freezing -18 °С, 7 days; salting of 12 % tuzluk 1 month; frying – from 15 minutes; action of microwaves 480 W, 8 minutes, 760 W, 4 minutes. The prevalence of apophalosis among fish of the Dnieper River basin (Sula, Psel, Vorskla) in Sumy region was established. The overall invasion intensity for all species of fish studied was 3.64 %. Effective for the disinfection of fish meat with the presence of Apofalus donicus metacercariae are: boiling at 80 °C, 15 minutes, at 100 °C, 10 minutes; freezing -18 °С, 7 days; salting of 12 % tuzluk 1 month; frying – from 15 minutes; action of microwaves 480 W, 8 minutes, 760 W, 4 minutes. In the future, it is planned to conduct research to determine the spread of apophalosis among cats, dogs and fish birds.