Diagnostics of Gymnocanthus pistilliger (Pallas, 1814) and G. galeatus Bean, 1881 (Scorpaeniformes: Cottidae) in their Cohabitation Areas

Abstract

Sex-independent characters for identification of Gymnocanthus pistilliger and G. galeatus in their cohabitation areas were revealed: the presence, position, and arrangement of rough bony plates on the interorbital space, as well as the total spine and ray count for all fins (dorsals and anal; doubled number of rays in pectoral). The interorbital space of G. galeatus is completely covered by bony plates; the spine and ray count for all fins is 82−89. In G. pistilliger, the interorbital space is naked (26%) or has only a few bony plates that never extend onto the rim of the orbit; the spine and ray count for all fins is 74−81. In the eastern part of the Sea of Okhotsk, G. galeatus is not common and perhaps might be found here only occasionally.