Parasitofauna of the Dolginsky herring in the Agrakhan Bay of the Caspian Sea

Abstract

The purpose of the research is to analyze the current state of the parasitofauna of the Dolginsky herring in the Agrakhan Bay of the Caspian Sea. Materials and methods. In 2021–2022, parasitological studies of 50 specimens of Dolginsky herring from the Agrakhan Bay of the Caspian Sea were performed. The parasitological autopsy was performed in accordance with the generally accepted methodology, microscopic examinations were performed using Lomo Micmed-5 and MBS-10 microscopes, the type of parasites, the extent of infection (EI), and the intensity of infection (AI) were determined. The species identification of helminths was carried out according to morphological characteristics using the determinants of freshwater fish parasites of the USSR edited by I. E. Bykhovskaya-Pavlovskaya and O. N. Bauer. Results and discussion. The modern helminth fauna of the Dolginsky herring in the northern part of the Agrakhan Bay includes 8 species of helminths dominated by Pseudopentagramma symmetricum (EI = 80–93.3%, EI – 25–700 sp.), Mazocraes alosae (EI = 71.4%, EI – 5–80 sp.), Anisakis schupakovi (EI = 71.7%, EI – up to 60 sp.). The Corynosoma strumosum scrapers previously discovered by other researchers have not been recorded by us. Due to the fact that herring is the main object of fishing in the Caspian Sea, it is necessary to pay attention to the high rates of invasion by nematodes, which pose an epidemic danger: A. schupakovi , Contracaecum sp., E. excisus .