On Structure of Species in Pelagic Fish: the Results of Populational— Genetic Analysis of Four Species of Lanternfish (Myctophidae) from the Southern Atlantic

摘要

Populational—genetic analysis of four species of lanternfish (Myctophidae), mass mesopelagic fish, was made for elucidation of mechanisms of isolation in the pelagial of the open ocean and participation in this process of large-scale and local populations. The analysis was based on samples from trawl catches in the course of the 29th cruise of RV Akademik Ioffe in 2009 to regions of the Mid-Atlantic Ridge and the Walvis Ridge. By means of several microsatellite loci, various types of intraspecies structure in ecologically similar species are shown in the areas of their sympatric life. Estimations of genetic differentiation in term of F_(ST) vary from 0 to 0.120. High estimations of interpopulational differences indicate that homogenizing influenceof large-scale circulations in some species may be limited. Various adaptive strategies which may prevent considerable migration are considered as a preliminary hypothesis. Evidence of a potential differentiating role of local circulations in zones of underwater rises is obtained.