Cottus perifretum Freyhof, Kottelat & Nolte 2005

Differs from other species of Cottus in the North Sea and Atlantic basins by the combination of the following characters: no distinct transverse bands on pelvic fin; prickling on body extending backwards to caudal peduncle in juveniles and most adults; sometimes absent in large males; first dorsal fin marbled or black in nuptial males; eye diameter 18-21% HL; interorbital distance 0.7-1.9 times in eye diameter; last anal-fin ray connected to body by a membrane along 0.1-0.90 of its length (Ref. 55856).

Analsoft rays: 11 - 13

Occurs in all kinds of streams and rivers including large main rivers, all kinds of shores with coarse gravel or large stones in flowing and stagnant water of rivers, harbors and backwaters (Ref. 55856). Feeds on a wide variety of benthic invertebrates (Ref. 59043).