Analysis of linear-weight parameters of narrow-clawed crayfish (Astacus) in water reservoirs of Dnipropetrovsk region

Abstract

This research focuses on studying the narrow-clawed crayfish in the Dnipropetrovsk region. The narrow-clawed crayfish, Astacus leptodactylus, is a crucial component of industrial fisheries and plays a significant role in the development of aquatic ecosystems. Within the territory of the Dnipropetrovsk region, crayfish inhabit various freshwater bodies, including rivers, lakes, floodplains, and ponds. It is known that water bodies in the Dnipro region undergo substantial anthropogenic impact, leading to alterations in the life cycles and reproductive features of hydrobionts. Investigated areas of reservoirs were characterized by diverse levels and factors of pollution, such as contamination of water with chemical and radioactive substances, oil products, wastewater, and the use of nitrogen and phosphorus fertilizers. These anthropogenic interventions may result in a decrease in populations of aquatic organisms, posing a serious threat to water ecosystems. The sensitivity to environmental changes makes crayfish a valuable bioindicator species. Fertility indicators and morphometric characteristics can be considered as bioindicators. The analysis of linear-weight parameters revealed that crayfish extracted from the Zaporizhzhia Reservoir had a body length 15–18% greater than those from the Kamianske and Samara Bay. Additionally, they exhibited larger cephalothorax dimensions by 18–20%, and their mass was almost 50% higher compared to individuals from other water bodies. Samara Bay demonstrated significantly lower fertility indicators compared to the Zaporizhzhia Reservoir, with crayfish fertility being reliably 63% lower. The established differences in morphometric indicators between crayfish from the Zaporizhzhia Reservoir, Samara Bay and Kamianske Reservoir may indicate heterogeneity in the living conditions within the water bodies of Dnipropetrovsk and might be induced by anthropogenic pressures.