Garra gymnothorax Berg, 1949

Distribution in the area. Endemic. Karun and Karkheh drainages.

Taxonomic notes. Garra gymnothorax might be a real cryptic species. It was described based on populations with a naked breast from the Karun in Iran (Berg 1949). However, most Garra from the Karun have a scaled breast and a naked breast is also found in some populations of G. rufa . In G. gymnothorax as well as in many populations of G. rufa, the scales on the breast are often embedded in the skin. In contrast to the diagnosis given by Esmaeili et al. (2016), the breast squamation is variable in G. gymnothorax and G. rufa and no morphological character has been described to distinguish both species. They are well distinguished by nuclear (Rhodopsin; Behrens-Chapuis et al. 2015) as well as mitochondrial (COI; Hamidan et al. 2014) characters. Garra gymnothorax seems to be most closely related to subterranean G. typhlops and G. lorestanensis, which occur within its range (Hashemzadeh Segherloo et al. 2016).