On the first occurrence of the rockling Gaidropsarus pakhorukovi Shcherbachev (Gairdropsarini, Lotidae, Gadidae) and on species diagnostics of G. pakhorukovi and G. parini Svetovidov

Abstract

Descriptions of rare species of rocklings of the southern hemisphere Gaidropsarus pakhorukovi (the Atlantic Ocean, Rio Grande Plateau) and G. parini (the Pacific Ocean, Nazca Ridge) are verified. A rockling caught for the first time on Rio Grande Plateau in 1974, whose classification previously was doubtful, is attributed to G. pakhorukovi. New diagnostic characters of closely related G. pakhorukovi and G. parini are found. In contrast to the existing opinion on the complete loss by bony fish of the primary fin skeleton of the caudal fin, a possibility of its phylogenetic reversion in gadiforms and dalliids, is suggested.