ACANTHOCEPHALUS AND NEMATODES OF FISH IN WATER BODIES OF THE SYRDARYA RIVER MIDSTREAMS

Abstract

The features of the nematode and acanthocephalus fauna of Cypriniformes and Siluriformes fish, their distribution in the water bodies of the Syrdarya River midstream were studied. In total, 18 helminth species belonging to the classes Nematoda – (14 species) and Acantocephala – (4) are registered in the region. 7 species we marked for the first time for the region of under consideration.Studies were conducted of different types of water bodies of the Syrdarya river in 2016–2019 years. The collection and study of helminths of fish were carried out by known methods in helminthology and ichthyoparasitology. 1239 copies of Cypriniformes fish belonging to 15 species (Cyprinidae – 12 species, Cobitidae – 3) and 12 specimens of Siluriformes fishes from the families (Siluridae and Clariidae) were researched.According to preliminary data, 18 species of helminths belonging to the class Nematoda (14 species) and to the class Acantocephala (4 species) were found in the studied fish orders in the reservoirs of the region. Significant species diversity is characterized by the class Nematoda. We have registered 14 species belonging to 4 orders. The detachment Trichocephalida Skrjabin et Schulz, 1928 is represented by one species – Capillaria tomentosa Dujardin, 1843, which is noted in most Cypriniformes in the natural and artificial reservoirs of the northeast of Uzbekistan. The greatest species diversity is distinguished by the detachment Spirurida Chitwood, 1933. We noted 8 species. The remaining units are represented by 1–2 species – banal fish parasites. The findings of Dioctophyme renale Goeze, 1782 (larvae) in Cypriniformes in the studied region should be noted.The Acanthocephala class is represented by 4 species: Neoechinorhynchus rutileMüller, 1780, Pomphorhynchus laevis Müller, 1776, Acanthocephalus lucii Müller, 1776 and A. anguillae Müller, 1780. Nematodes are dominant. The results suggest that the most optimal conditions for the functioning of the corresponding helminth communities probably exist in the water bodies of the Syrdarya’s midstream. The abundance of a number of invertebrate groups, the inhabitants of aquatic ecosystems, which are intermediate hosts of parasites, the accumulation of waterbirds and mammals contribute to the irreversible circulation of helminths in aquatic cenoses of the study area. All this requires systematic monitoring of fish helminthiasis in order to develop preventive measures.