Gobio artvinicus

Gobio artvinicus View in CoL View Figure

Common name. Colchic gudgeon.

Diagnosis. Distinguished from other species of Gobio in West Asia by: ○ 39–42 total lateral-line scales / ○ chest between pectorals naked or covered by scales / ○ scales on belly approximately equal or slightly larger than pupil diameter / ○ scales on base of pectoral usually embedded / ○ pectoral reaching 3–4 scales in front of pelvic origin in mature male / ○ head length 24–26 % SL / ○ head width at anterior eye-margin 11–12 % SL / ○ distance between pelvic origin and anal origin 2.8–3.3 times in distance between anus and anal origin / ○ 6 scales rows between lateral line and dorsal origin / ○ 4–5 scales between lateral line and anal origin / ○ 4–6 scales between anus and anal origin / ○ 5–6 scales between posterior extremity of pelvic base and anus / ○ interorbital distance 1.1–1.6 times in eye diameter /

○ snout pointed, not or slightly concave anterior to nostril / ○ 5–8 mid-lateral blotches. Size up to 107 mm SL.

Distribution View Figure . Eastern Black Sea basin from Rioni ( Georgia) south to Çoruh ( Türkiye). Non-native and spreading in Kura and Aras drainages.

Habitat. A wide range of lowland and foothill streams and rivers, usually in slow to moderately fast-flowing waters on sand or gravel bottoms. Absent from high altitude streams with fast currents and low water temperatures.

Biology. No data.

Conservation status. LC.

Remarks. This species is much more variable than originally described, and the diagnostic characters need to be

re-examined in the future. While fish from the Çoruh have a bare or incompletely scaled chest, the scales of populations from the Rioni and the Caspian basin cover the chest. There is some confusion about this species with G. caucasicus , which occurs in the adjacent Caucasian Black Sea basin and Caspian basin of Russia, and G. artvinicus is likely a synonym of G. caucasicus .

Further reading. Turan et al. 2016a (description); Epitashvili et al. 2020 (distribution); Kaya et al. 2020a (distribution); Yeşilçiçek 2022a (size).