Ponticola rizensis (Kovacic & Engin, 2008)

Freyhof, JÖrg, Yoğurtçuoğlu, Baran, Jouladeh-Roudbar, Arash & Kaya, Cüneyt, 2025, Handbook of Freshwater Fishes of West Asia, De Gruyter : 673-674

Ponticola rizensis

Common name. Colchic goby.

Diagnosis. Distinguished from other species of Ponticola entering freshwater in West Asia by: ○ lateral part of upper lip distinctively swollen / ○ lower jaw prognathous / ○ predorsal area uniform brown or dark-grey / ○ first dorsal without bold, distal, dark-brown band / ○ head depressed, wider than deep / ○ 59–73 +3 scales in midlateral series / ○ caudal peduncle depth 18–22 % of caudal peduncle length / ○ two suborbital transverse rows below suborbital longitudinal row b / ○ pelvic disc reaching 40–60 % of distance between its origin and anus / ○ pelvic-disc fraenum with angular lobes whose length is 1 ⁄ 6 – 1 ⁄ 2 of fraenum width at base. Size up to 124 mm SL.

Distribution. Türkiye: Aksu ( Giresun) east to Hopa drainages.

Habitat. Cold mountain to warm foothill streams. Not found in brackish water.

Biology. Male guard eggs in gravel or rocky burrows. Feeds mainly on small fish and a variety of invertebrates.

Conservation status. VU; appears to be slowly declining within its relatively small range.

Remarks. Molecular characters do not distinguish P. rizensis and P. turani from each other but clearly distinguish both together from P. constructor . Published morphological data place P. constructor somewhere between these two species. However, all characters used to differentiate P. constructor , P. rizensis , and P. turani largely overlap in fresh material we examined, and further studies are needed to distinguish at least the two species supported by molecular characters ( P. constructor and P. rizensis ). Ponticola rizensis and P. turani have been published in the same study. As a first reviser, we give priority to P. rizensis over P. turani . This makes P. turani a synonym of P. rizensis . Ponticola west of Aksu might belong to this species.

Further reading. KovačiĆ & Engin 2008 (description).