Morphological characteristics of the Amur false gudgeon Abbottina rivularis (Gobioninae) from the River Karatal (Balkhash basin)

Abstract

The article is devoted to the study of the external morphological features of the Amur false gudgeon, a wellknown invasive species from East Asia that entered the water bodies of Kazakhstan more than 60 years ago and successfully dispersed throughout the Aral and Balkhash-Alakol basins, as well as the Sarysu, Talas and Chu river systems. Like other alien species, Amur false gudgeon has a negative impact on the native fish fauna. Over the years of acclimatization, this alien species has become a full representative of the ecosystems of water bodies and has taken its place in the list of fish in Kazakhstan. Despite this, modern data on the distribution and morphological variability of the Amur false gudgeon in the Kazakhstan basins are insufficient. 20 specimens of the Amur false gudgeon caught in the River Karatal of the Balkhash basin were used for morphological analysis. To analyze meristic characters and scale cover, the specimens were entirely stained with Alizarin Red. Data on the variability of plastic and meristic features were obtained, and for the first time, the features of the scale cover of this species in water bodies of Kazakhstan were studied in detail. A detailed morphological characteristic of the Amur false gudgeon with illustrations is given. In comparison with the information on the Amur false gudgeon from the River Issyk (Ili basin) some differences in plastic characters are revealed, at the same time, meristic characters are similar to the available descriptions of this species. For a more complete assessment of the morphological variability of the Amur false gudgeon, further studies of its populations in the water bodies of Kazakhstan are required.