Proterorhinus nasalis (De Filippi, 1863)

Freyhof, JÖrg, Yoğurtçuoğlu, Baran, Jouladeh-Roudbar, Arash & Kaya, Cüneyt, 2025, Handbook of Freshwater Fishes of West Asia, De Gruyter : 677-678

Proterorhinus nasalis

Common name. Eastern tubenose goby.

Diagnosis. Distinguished from other species of Proterorhinus in Caspian basin by: ○ eye diameter 20–28 % HL / ○ usually 14, rarely up to 16½ branched anal rays. Size up to 90 mm SL.

Distribution. Caspian and Azov basins. Native to Volga delta, now reaching as far as Lake Rybinskoye. Reached eastern Baltic basin in Russia, Estonia and Finland in recent years.

Habitat. A variety of slow-flowing or still waters. Usually associated with dense vegetation or coarse rocks.

Biology. Spawns first time at 1–2 years, usually for 1–2 seasons, in April–August. Females spawn more than once in a season. Male guard eggs deposited in burrows. Larvae and juveniles benthic. Feeds on benthic invertebrates.

Conservation status. LC; invasive in Volga and Baltic basin, where it is spreading, reportedly facilitated by

Proterorhinus nasalis ; Azov basin, Ukraine; ~ 50 mm SL.

canalisation of main rivers and reservoirs or slow-flowing waters created by hydroelectric plants.

Remarks. In recent literature, this species has been misidentified as P. semipellucidus , a species potentially endemic to the Iranian Caspian basin. It cannot be excluded that P. semipellucidus might be a valid species, and future research is encouraged to investigate this question. In recent literature, this species has been misidentified as P. semipellucidus , a species potentially endemic to the Eastern Caspian basin. Proterorhinus semipellucidus was redescribed too late to get full credits in this book. It can be identified by the key on page 675.

Further reading. Miller 2004 (description, biology); Naseka et al. 2005 (invasion); Zarei et al. 2021 (phylogeny); Kurina et al. 2024 (Baltic invasion); Vasil’eva et al. 2025a ( P. blennioides ); Vasil’eva et al. 2025b ( P. semipellucidus ).

Proterorhinus semilunaris ; Lake Sapanca, Türkiye; female, ~ 35 mm SL. Proterorhinus semilunaris ; Lake Sapanca, Türkiye; male, ~ 55 mm SL.