Clupeonella Kessler, 1877
Diagnosis: small silvery fishes, elongate, somewhat compressed; belly with a distinct keel of scutes. Lower jaw projecting; gillrakers 41-62 on lower part of first arch. Pelvic fin origin below about middle of dorsal fin base; last two anal finrays enlarged; no wing-like alar scales at base of caudal fin. Colour: back blue/green, flanks silvery. Size: to 14.5 cm, usually 6-10 cm.
Habitat: pelagic, euryhaline, essentially a brackish-water species (tolerating salinities up to 13%), but with semi-anadromous and purely freshwater forms in rivers and lakes; shoaling, with migrations between winter or autumn feeding and summer spawning grounds. Food: zooplankton, chiefly copepods, also cladocerans, rotifers, mysids, mollusc larvae and small fishes. Reproduction: In early summer in the Sea of Azov (peak in May) and in the lower reaches of rivers (e.g. the Dnieper and Dniester, from about May), the latter populations then spending the rest of the summer in the Black Sea before returning to the rivers in August to November.
Distribution: brackish waters of the north-western part of the Black Sea and also Sea of Azov and Caspian (the subspecies C. cultriventris caspia); also, most of the affluent rivers of the area, reaching as far as 60 km upstream. An abundant species and among the top commercial fishes of the Sea of Azov.
Species 4, in Clofnam area 1.
Recent revisions: Svetovidov (1952—in Russian; 1963—English translation).