The Kuban gudgeon and Little Kuban gudgeon are restricted to the sections with moderately fast flow and gravel or sandy bottoms; they are abundant in the middle part of the river. The Kuban gudgeon is unusual by having five anal branched rays. Aphips chub ("Squalius aphipsi") occurs in southern tributaries of Kuban and is hiding in small pools in the summer. It spawns in rapid streams deep with a pebble or rocky bottom. It does not migrate much, but it moves downstream in winter to find deeper pools and returns upstream in summer. This species is abundant throughout the whole river.