Fish parasitofauna of the amudarya river delta lakes

Karakalpak State University named after Berdakh, Nukus city 230112, Republic of Karakalpakstan, Uzbekistan

Abstract

The paper deals with changes in the parasitofauna of some fish species of the Amudarya delta lakes. Recent data on the parasitofauna of 8 indigenous commercial fish species of the Amudarya delta lakes in the degraded natural environment (2019-2023) are presented. Impoverishment of ichthyoparasite fauna under the influence of continuous anthropogenic pressure and its causes is shown. Species of parasites with constant high infestation and pathogenic forms that are potential agents of fish diseases in extreme environmental conditions of the region are indicated. The research conducted between 2019 and 2023 revealed a significant reduction in parasite species previously widespread among commercial fish in the lakes of the Amudarya River delta. Anthropogenic factors, such as water pollution by industrial and agricultural wastes, as well as the reduction of water levels in the river due to intensive use of water resources for irrigation, played a decisive role in these changes. A detailed analysis of the factors causing changes in the fish parasitofauna has shown that anthropogenic impacts, including pollution, changes in the water temperature regime and its chemical composition, are causing significant changes in the ecosystem of the Amudarya delta lakes. In the future, this may lead to even greater changes in the microbiological composition of the water and, as a consequence, to the emergence of new epidemics among fish.