Biodiversity of Arctic fishes: first karyological information on Gaidropsarus argentatus (Reinhardt, 1837), a new piece to the puzzle

As widely acknowledged, climate changes are occurring at a very fast pace in the Arctic region, leading to inevitable changes in the Arctic marine ecosystems, therefore baseline information on the current status of marine fish diversity is both essential and urgent. In this context, we provide the first cytogenetic characterization of the Arctic gadoid fish Gaidropsarus argentatus (Arctic rockling). The analysis of specimens collected along the coasts of Greenland during TUNU-MAFIG (Marine Fishes of North East Greenland – diversity and adaptation) expeditions, consistently indicated 48 chromosomes, with karyotypic formula 12 m/sm + 36 st/t and fundamental number (FN)=60. Comparison of the cytogenetic data of G. argentatus with those of the co-generic G. mediterraneus revealed a surprisingly high level of divergence between these co-generic species.The present data on G. argentatus represent an important piece of information, essential for future analyses aiming at clarifying the chromosomal evolution and diversification within Gadidae. Moreover, the description of the species-specific karyotype for one of the 242 species living in Arctic marine waters enlarges our knowledge of the Arctic ichthyofauna, thus contributing to build baseline biological information for future monitoring of biodiversity changes in polar regions.