Knipowitschia longecaudata (Kessler, 1877)

Freyhof, JÖrg, Yoğurtçuoğlu, Baran, Jouladeh-Roudbar, Arash & Kaya, Cüneyt, 2025, Handbook of Freshwater Fishes of West Asia, De Gruyter : 688-689

Knipowitschia longecaudata

Common name. Longtail dwarf goby.

Diagnosis. Distinguished from other species of Knipowitschia entering freshwater by: ● caudal asymmetric, upper part longer than lower part / ○ anterior extremity of anterior oculoscapular canal in front of middle of eye (pore σ) / ○ anterior oculoscapular canals usually fused in posterior interorbital space, with a single pore λ, rarely canals not extending to interorbital space / ○ flank and caudal peduncle covered by scales, with more than one series along lateral midline / ○ otic transverse row tra of papillae on cheek not reaching to row b / ○ no transverse row of papillae on cheek through row d / ○ posterior oculoscapular canal absent / ○ back naked in front of origin of second dorsal / ○ body with 4–8 dark bars in live nuptial male / ○ 33–40 total scales in midlateral series. Size up to 40 mm SL.

Distribution. Caspian, Azov, northern and western Black Sea basins.

Habitat. Fresh to salt waters of coastal lakes, reservoirs, estuaries, and lagoons in shallow, well-vegetated habitats. Rarely in large rivers where it might occur far upstream.

Biology. Lives <2 years. Spawns after first winter, at 20 mm SL, March–July. Female may spawn several times in a season. Male defend eggs in cavities under stones, plant material, or mollusc shells. Feeds on small invertebrates.

Conservation status. LC.

Remarks. This species has not been found along the Black Sea coast of Türkiye, Russia, and Georgia and may be absent from the Asian Black Sea basin. Fish identified as this species from the Danube delta and the lower Don share their COI DNA sequences with K. caucasica , and no K. longecaudata has been positively identified by molecular methods. This suggests that K. caucasica may have introgressed at least parts of populations.

Further reading. Miller 2004 (description, biology); Zarei et al. 2022a (records from Iran).

Knipowitschia mermere ; Gediz drainage, Türkiye; 25 mm SL.