Амурский чебачок Pseudorasbora parva (Cyprinidae) в водоемах и водотоках Дагестана

Abstract

Information is provided on the distribution of a species alien to the ichthyofauna of Dagestan – the Amur Top-mouth gudgeon Pseudorasbora parva (Temminck et Schlegel, 1846) within the region. It was found that the species expanded its range in the region under consideration, in 2021 it was found in the rivers Manasozen (9 copies), Gamriozen (10 copies), Ulluchai (6 copies), Rubas (6 copies), Avar koisu (a tributary of the Sulak River, in the area of the Gotsatli HPP), as well as in L. Mooch. It is assumed that the widespread distribution of P. parva is associated with high ecological plasticity, migration activity of larvae and fry, their high survival rate, rapid growth and accelerated puberty. The presented morphological variability of the Amur Topmouth gudgeon population based on the study of 20 signs, including 5 meristic and 15 plastic, revealed a slight variability of morphological signs due to different habitat conditions in the region. The Amur Topmouth gudgeon is a natural focus of an infectious disease of the swim bladder, dangerous for autochthonous ichthyofauna and aquaculture facilities, and a food competitor and consumer of caviar and larvae of autochthonous fish. With high numbers and prolonged starvation, P. parva can be a serious competitor for juvenile carp and variegated carp, and exhibit a predatory reaction towards commensurate juveniles of commercially valuable fish species. To control the number of this alien in the region, it is advisable to use native predators – perch Perca fluviatilis (Linnaeus, 1758), pike Esox lucius (Linnaeus, 1758) and walleye Sander lucioperca (Linnaeus, 1758).