Morphometric characters of the whitefish ludoga (coregonus lavaretus ludoga) in connection with the lake Issyk-Kul ecological and geographical conditions and its introduction

Abstract

This article considers the influence of ecological and geographical conditions in the sequent whitefish ludoga (Coregonus lavaretus ludoga) relocation from Lake Ladoga to Lake Sevan and then from Lake Sevan to Lake Issyk-Kul. Morphometric studies of whitefish ludoga from Lake Issyk-Kul and a comparative analysis with similar data of this fish species of Lake Ladoga and Lake Sevan were carried out, taking into account the ecological and geographical condition of these lakes. In the course of our research, we found that the morphometric characters of whitefish ludoga during the introduction from Lake Ladoga to Lake Sevan and then to Lake Issyk-Kul changed due to the ecological and geographical conditions of these lakes. We have identified changes that occurred sequentially when moving from the plain region lake (Ladoga) to the mountain lake (Sevan) and to the mountain lake with brackish water (Issyk-Kul). These changes were mainly in the quantitative increase of some morphological parameters of these fish, such as raker counts on first branchial arch; scale counts on the lateral line; snout length and lower jaw length; predorsal distance and caudal peduncle length; head depth. In addition, there are changes characteristic of the Issyk-Kul fish, it is an increase in body depth and the dorsal fin height.