Knipowitschia caucasica (Berg, 1916)

Freyhof, JÖrg, Yoğurtçuoğlu, Baran, Jouladeh-Roudbar, Arash & Kaya, Cüneyt, 2025, Handbook of Freshwater Fishes of West Asia, De Gruyter : 686-687

Knipowitschia caucasica

Common name. Caucasian dwarf goby.

Diagnosis. Distinguished from other species of Knipowitschia in West Asia by: ● head canals usually complete, rarely posterior oculoscapular reduced / ○ anterior oculoscapular canals usually fused in posterior interorbital space, with a single pore λ / ○ flank and caudal peduncle covered by scales, with more than one series along lateral midline / ○ anterior extremity of anterior oculoscapular canal in front of middle of eye (pore λ) ( Fig. 64 ) / ○ otic transverse row tra of papillae on cheek not reaching to row b / ○ no transverse row of papillae on cheek through row d / ○ caudal symmetric. Size up to 50 mm SL.

Distribution. Coasts of Black, Azov, Caspian, and Marmara Seas. Also, along northern Aegean west to Aliakmon drainage ( Greece). Introduced in Karamanlı Reservoir, Lakes Beyşehir, Eğirdir and Eber basins, Büyük Menderes drainage and some places around Antalya ( Türkiye). Also introduced to Aral Sea (now extirpated). Invasive in lower Rhine (North Sea basin).

Habitat. Fresh to hypersaline waters (salinity up to 55 ‰) of lakes, estuaries, and lagoons. Most common in shallow, well-vegetated habitats.

Biology. Lives <2 years. Spawns after first winter in March– July at 20–23 mm SL, releasing up to four portions of eggs. Eggs are attached to roof of a burrow under stones, plant material or shells, defended by male. Postlarvae pelagic. Feeds on small invertebrates.

Conservation status. LC.

Remarks. The origin of introduced populations in Türkiye appears to be the Maritza drainage in European Türkiye, as fish farms in this region were a major source of carp stocked throughout Anatolia. Molecular data also support this hypothesis. Within K. caucasica , several molecular groups differ slightly from each other.

Further reading. Economidis & Miller 1990 (systematics); Daoulas et al. 1993 (reproduction); Economou et al. 1994 (reproduction, Trichonis population); Bianco & Ahnelt et al. 1995 (distribution, systematics); Vasil’eva & Kuga 2001 (osteology, systematics); Vasil’eva et al. 2004 (biology); Küçük et al. 2009b (introduction in Eğirdir); Ahnelt 2011 (introduction to Central Anatolia); Tarkan et al. 2015 (distribution).

Knipowitschia caunosi ; Lake KÖyceğiz, Türkiye; ~ 20 mm SL.

Figures

Figure 64. Anterior oculoscapular canal ending: a, on snout (pore σ) in Pomatoschistus species; b, in front of middle of eye (pore λ) in some Knipowitschia species; c, behind middle of eye (pore К) in some Knipowitschia species.