Clupeonnella cultriventris Nordmann, 1840
Synonyms: Clupea cultriventris Nordmann, 1840; Clupea delicatula Nordmann, 1840; Clupeonella delicatula Svetovidov, 1952
Common names: Engl: Tyulka sprat; Bulg: Ezerna tritsona; Rom: Gingirica; Russ: Tyul'ka; Turk: Tilka
Taxonomic descriptions: D 14-16; A 17-21; P 13-16; V 8; C I 17 I; Keeled scales 26-30; Gillrakers 41-62; Vertebrae 41-43 (16-18 + 17-19) (Sivkov, 1994). Body elongated, laterally strongly depressed. Body width 0.08-0.11 SL. Belly with a sharp edge of keeled scales. Last two anal finrays enlarged. Size: to 10.5 cm.
World level: NE
Black Sea Regional level: EN
Subregion level: EN
Distribution: Brackish waters of the north-western part of the Black Sea and Sea of Azov and Caspian (Whitehead, 1984). In Bulgaria: Lakes Shabla, Varna, Burgas; the Bay of Varna (Stojanov and all., 1963).
Habitats type, Critical habitats, Limiting factors: Shoal, pelagic, euryhaline, essentially in brackish waters; shoal and brackish waters; chemical pollution of the coastal lakes.
Biology: Reproduction: April-June on the Bulgarian coast. Food: zooplankton, copepods, mollusc larvae and small fishes.
Population trends: Declining.
Threats: Chemical pollution of the coastal lakes.
Conservation measures taken: Lake Shabla has been made a reserve. The species is included in the Bulgarian Red book (Karapetkova, 1985).
Conservation measures proposed: Cessation of the pollution.
Compiled by: Y.Sivkov, K.Prodanov