In this paper the writer deals with the breeding habits of the fresh-water suker, Abbottina rivularis (BASILEWSKy), a small cyprinoid fish. The usual habitats of the fish are the slow streams with muddy bottom. The spawning season lasts from beginning of March to early May. In the breeding male numerous horny tubercles appear on the snout, anterior part of the cheek, pre-opercle region and on the outer margin of pectoral fins. Dusky and yellow nuptial coloration also appears on the body.
The male fish prepairs a nest on the muddy bottom in the shape of a round, shallow depression, 20-40 cm. in diameter and 3-5 cm. in depth. In this nest about 2, 000-4, 000 eggs are deposited, over which the male parent fish eagerly keeps guard until the hatched larvae attain the end of the post-larval stage, about 10mm. in total length. The egg is spherical in shape and about 1.4mm. in diameter, with a jelly-like coating of about 1mm. in thickness. The surface of the jelly coat is covered with mud.
