The first record of oriental river prawn Macrobrachium nipponense (De Haan, 1849 [in De Haan, 1833–1850]) (Decapoda: Palaemonidae) in the Ukrainian part of the Danube Delta

Abstract

The alien shrimp Macrobrachium nipponense (De Haan, 1849 [in De Haan, 1833– 1850]), oriental river prawn has been identified in the water bodies of the Ukrainian part of the Danube Delta for the first time. Diagnosis of the species is based on measurements of 35 specimens. Characteristic features: the dorsal side of rostrum armed by 12–13 teeth, with feathery setae between them, 3 (rarely 2) teeth located on the ventral side of rostrum. During 2019–2020, the freshwater shrimp, M. nipponense, has become a common element of the benthic fauna of the Kiliya arm of the Danube River. It is supported by regular registrations of numerous shrimp aggregations in different parts of the arm (from the 32nd to the 80th km of the main stream) since the summer of 2019. The record of this alien shrimp species potentially confirms its introduction from other water bodies of the North-Western Black Sea Coastal Area to the Danube Delta by the natural dispersion or the unauthorized introduction. Although the known records suggest an accidental introduction of this species into the area close to the lakes of the Lower Danube area, both hypotheses require further investigation and approbation.