Squalius janae, a new species of fish from the Adriatic Sea basin in Slovenia (Actinopterygii: Cyprinidae)

Squalius janae, sp. nov., is described from the upper Dragonja River system in the Adriatic Sea basin in Slovenia. The new species is distinguished from other members of the S. cephalus species group by a combination of the following characters: a long head, head length, 29−32% SL, always markedly exceeding body depth; a pointed conical snout; a slightly subterminal mouth, with a clearly projecting upper jaw; a long straight mouth cleft; lower-jaw length 39−45% HL, always greater than caudal-peduncle depth; a large eye, its diameter 19−25% HL; a large triangular 5 infraorbital; a marked discontinuity between the dorsal profile of the head and body; usually 44−47 total lateral-line scales; usually 91⁄2 branched anal-fin rays; usually 44 total vertebrae (24+20 and 25+19); a strong silvery tint in colouration; scales easily lost; iris, pectoral, pelvic and anal-fin pigmentation with yellow shades; flank scales margined by a few black pigment dots along their free margin and intense pigments on scale pockets, forming vertically elongate black spots.