The lake chub, Couesius plumbeus, is a freshwater cyprinid fish found in Canada and in parts of the United States. Of all North American minnows, it is the one with the northernmost distribution. Its genus, Couesius is considered monotypic today. The genus was named after Dr. Elliott Coues, who collected the holotype specimen. The body is elongate, usually 100 mm (4 in) long, though some individuals twice that length have been found. The back is olive-brown or dark brown, and the sides are leaden silver, hence the word plumbeus, referring to lead, in the scientific name of this fish. The snout is blunt and projects slightly beyond the upper lip. The corners of the mouth each bear a small barbel. The scales are small but well visible, and some may be black and form isolated dark spots on the lower sides. The dorsal, pelvic and anal fins each have 8 rays. The pectoral fins are broad and have 13-18, but more usually 15-16, rays. Breeding males can develop patches of bright orange or red at the base of the pectoral fins and sometimes near the mouth, and small nuptial tubercles on the top of the head, dorsal surface of pectoral rays, and on the belly near the base of the pectorals.
No comments:
Post a Comment