Gila robusta

The roundtail chub (Gila robusta) is a cyprinid fish in the genus Gila, of southwestern North America. It is native to the Colorado River drainage basin, including the Gila River and other tributaries, and in several other rivers. It is part of the “robusta complex”, which includes the Gila robusta robusta, G.r. grahami, and G.r. seminuda. The body of the roundtail chub is significantly larger forward of the dorsal fin, and posteriorly it is tapered towards the tail. The forehead area is concave. The mouth is largish, but does not reach as far as the pupil of the eye, and is overhung by the snout. The tail is deeply forked. Color is a grayish brown above, and a lighter shade below. Mature males sometimes acquire red-orange lower cheeks and paired fins during breeding season. Roundtail chub can reach almost 49 cm (19.5 in), but usually only grow to about 25–30 cm (10–12 in). Recently, it has been recorded at up to 43 cm in length. Roundtail chub are also described to be “trout-like” because they possess a large mouth with the lower lip outlined in black. However, they lack the adipose fins found on trout species.