Caspian Bighead Goby Neogobius gorlap Iljin in Berg, 1949 (Gobiidae, Pisces)—a New Invader Species in the Moscow River

摘要

A population of the Caspian bighead goby, an invader species expanding its range, has been found in the Moscow River within Moscow for the first time. It is the first known river population of bighead gobies in the Volga River basin. Results of the study of distribution, feeding, and growth of gobies are presented. Bighead gobies occupy in the river a peculiar artificial biotope—a breakwater made of big stones dumped into the water and adjacent sites of the bottom. The food base of bighead gobies inthe Moscow River is composed of fish whitebait and to a lesser extent large invertebrates. A similar pattern of feeding of bighead gobies is observed in the Caspian Sea, but not in reservoirs of the Volga River. The growth rate of bighead gobies in theMoscow River is relatively high and only concedes to the growth rate of gobies from the Caspian Sea. Several assumptions on the invasive potential of the species are presented.