Sympatric morphotypes of the restricted-range Tashan Cave Garra: distinct species or a case of phenotypic plasticity?

The first record of a stygobiotic form of Garra rufa (Heckel, 1843), sympatric with Garra tashanensis Mousavi-Sabet, Vatandoust, Fatemi & Eagderi, 2016 (Teleostei, Cyprinidae), in Iranian subterranean waters

“…The Tang-e-Ban G. tashanensis mostly differs from the type-bearing phenotype from Tashan cave in the body shape expressed in many relative measurements, commonly 2 unbranched dorsal-fins; a narrower disc; an arched mouth; and, the most striking difference, a well-developed lateral-line, with 10-34 pored scales imbedded into skin or externally visible (vs. up to maximum of 7 pores without visible scales). Morphological diversity of G. tashanensis is even higher as there is one more phenotype, a discless form, that occurs in syntopy with the discbearing phenotype in Tashan Cave (Hashemzadeh Segherloo et al 2022;our data).…”