Chromosome Complement of Pomatoschistus marmoratus and Karyotype Evolution in Sand Gobies (Gobiidae: Gobionellinae)

The family Gobiidae constitutes one of the most diverse groups among teleost fish; some of its species are objects of aquaculture and fisheries. Despite many years of cytogenetic studies, the chromosome complements of many species of gobies remain unknown, and the trends of karyotypic evolution are poorly understood. Here I describe a previously unstudied karyotype of a widespread species from the group of sand gobies (Pomatoschistus marmoratus) and analyze the trends of karyotypic evolution of this group in comparison with other taxonomic groups of gobies from the Atlantic-Mediterranean and Ponto-Caspian regions. For P. marmoratus, the diploid number is 2n=46; it consists of 11 pairs of submetacentric chromosomes, 12 pairs of subtelocentric and telocentric chromosomes (NF=68). A comparative karyological analysis showed that the main trend in the karyotypic evolution of sand gobies differs from that of other groups of gobies and is associated with an increase in the number of chromosomal arms as a result of chromosomal rearrangements leading to a change in the centromere position. The results obtained contribute to understanding the role of chromosomal rearrangements in the evolution of Gobiidae and are of interest for further cytogenetic studies of this large family of fish.