Infection of bream with Ligula plerocercoids (Ligula intestinalis) of the Chernovsky reservoir of the Orenburg region

Abstract

In recent years, much attention has been paid in the Orenburg region to the issues of increasing fish stocks in natural and artificial reservoirs. Annually, the Ural River, reservoirs of the region are stocked with carp, sturgeon species of fish, as well as land reclamation activities. One of the reasons that worsen the quality of fish products from the reservoirs of the region is helminthiases. They reduce fatness and fat content, spoil the marketable appearance of caught fish, thereby causing significant economic damage [1]. Ligullosis is a common helminthic disease of many species of freshwater fish, especially often recorded in cyprinids. The disease in fish is caused by plerocercoids of Ligulidae from the genus Ligula (family Ligulidae). Parasitizing in the abdominal cavity, the helminth compresses the internal organs, disrupts their functions, which can lead to atrophy and infertility [2]. The natural causes of the spread of ligulosis include fish-eating birds - the final hosts of the Ligula. In the intestines of birds, helminths become sexually mature and live only a few days, standing out with litter and not causing much harm. It is quite difficult and not always possible to control the number of fish-eating birds in water bodies [3]. The aim of our research was to study the degree of infestation of bream with plerocercoids of the genus Ligula in the Chernovsky reservoir of the Orenburg region.