Garra tashanensis, Mousavi-Sabet, Vatandoust, Fatemi & Eagderi, 2016

Freyhof, JÖrg, Yoğurtçuoğlu, Baran, Jouladeh-Roudbar, Arash & Kaya, Cüneyt, 2025, Handbook of Freshwater Fishes of West Asia, De Gruyter : 219-221

Garra tashanensis

Common name. Tashan cave garra.

Diagnosis. Distinguished from other species of Garra in Persian Gulf and endorheic basins in Iran by: ● lateral line on body reduced, visible pores absent / ○ eye reduced and invisible externally / ○ whitish or pink, without colour pattern / ○ body almost naked, few scales at pelvic base only / ○ 9+8 branched caudal rays / ○ 7½ branched dorsal rays / ○ rostral cap well developed, completely covering upper lip / ○ gular disc fully developed as long as wide / ○ two pairs of normally developed barbels. Size up to 35 mm SL.

Distribution. Iran: Tashan Cave at Sarjusher and Tang-e Ban spring in Jarahi drainage.

Biology. Feeds on periphyton and detritus. In captivity, individuals reach sexual maturity at five to six months.

Conservation status. EN; appears to be declining within its very small range.

Remarks. The Laggashaylon population appears to bridge the morphological gap between G. smartae and G. sindhae , and published molecular data suggest that this population may represent an undescribed species. Garra smartae has been erroneously treated as a synonym of G. dunsirei , which is well differentiated and, as a subterranean species, has its own distinct evolutionary trajectory when compared to G. smartae . Described as Garra smarti , but the species name is dedicated to a female and must, therefore, be declinate to G. smartae .

Further reading. Krupp & Budd 2009 (description); Lyon et al. 2016 (phylogeny); Freyhof et al. 2020 (distribution, identification); Sayyadzadeh et al. 2023 (phylogeny).

Habitat. Underground waters.

Biology. No data.

Conservation status. EN; appears to be declining within its very small range. Only two locations are known: Tashan cave and Tang-e Ban spring. Tashan cave spans approximately 900 m in length and reaches a depth of about 50 m. Tang-e Ban is a seasonal karstic spring that only flows during winter and spring, during which fish are washed from the cave to the surface.

Further reading. Mousavi-Sabet et al. 2016c (description).

Did freshwater fishes cross the Bab-al-Mandeb? Numerous studies concern species movements between Africa and Eurasia, including the migrations of early humans ‘out of Africa’. A frequently cited dispersal route is across a land bridge in the southern Red Sea, which is suggested to have emerged during glacial sea-level low stands. The existence of a land bridge between Africa and the Arabian Peninsula is supported by numerous biogeographical similarities between the two regions, as evidenced by the distribution of different animal groups. This is the land bridge over the Bab-al-Mandeb Strait between Yemen and Djibouti. However, the precise timing of the final opening of the Red Sea to the Gulf of Aden remains a matter of contention, and the exact manner and timing of the entry of Asian freshwater fishes into Africa remain unclear. Geological data prove that Africa and Arabia were the last to be connected at the Bab-al-Mandeb-strait during the Miocene (10–5 million years ago). Postulated land bridge periods in younger, post-Miocene times are not supported. This indicates that no early humans or other biota, such as freshwater fishes, have walked on dry land or swam in freshwater from Djibouti to Yemen or vice versa. Following the Miocene, freshwater fishes could no longer cross the Bab-al-Mandeb Strait. However, they could still reach Africa from Asia via the Levant and the northern Arabian Peninsula and possibly through the Nile. It is evident that most freshwater fishes migrated from Arabia to Africa before the end of the Miocene, yet the specific dispersal routes remain uncertain.

Today, all native Arabian freshwater fish species are closely related to species in the Persian Gulf basin and not to African fishes. The only group of Arabian freshwater fishes that are not closely related to other West Asian species are the Garra of the G. tibanica group ( G. tibanica , G. buettikeri , G. dunsirei , G. smartae , and G. sindhae ). Indeed, Ethiopian G. makiensis is also related to the G. tibanica group. This supports the hypotheses of dispersal events and vicariance around the southern Red Sea area. However, G. makiensis is not very closely related to the species of the G. tibanica group, indicating that the last common ancestor lived much earlier than the late Miocene. The last common ancestor of all the other African Garra species is related to the last common ancestor of the many species of the G. rufa group. It has invaded Africa independently, probably through the Levant and the Nile. Further reading. Bosworth et al. 2005, Fernandes et al. 2006, Autin et al. 2010 (Bab-al-Mandeb-strait); Stewart & Murray 2017 (fossils of Awash); Englmaier et al. 2020 (relationship of Arabian and Ethiopian Garra ).

Garra tiam ; Abshur drainage, Iran; ~ 60 mm SL.