Scientific Name
Cottus immaculatus
Common Name
Knobfin sculpin
Biology
Dorsal
spines
(total): 7 - 9;
Dorsal
soft rays
(total): 15-19;
Anal
soft rays: 12 - 14. Distinguished from all other congeners, except Cottus hypselurus and Cottus caeruleomentum, by the blue chin and belly on spawning males. Differs from Cottus hypselurus by dorsal fin spines 8-9 (versus 6-7); pectoral fin rays 16-17 (versus 13-15); pigmentation of the ventral surface of the peritoneum weak (versus moderate to strong ); dorsal-fin union moderate to wide versus slight to moderate. Can be differentiated from Cottus caeruleomentum by caudal base band notched (versus non-notched); dorsal fins moderately to widely connected (versus slightly connected); pectoral fin rays 16-17 (versus 12-15); ventral surface of peritoneum weakly pigmented (versus moderately to strongly pigmented) (Ref. 83416).