Subterranean Fishes of the World

Country

Types

Holotype: ZMUC P26475 38.0mm SL. Paratypes ZMUC P26476-80 16.5mm - 34.5mm SL (5 specimens). This species is the type species by original designation and monotypy of the cave-restricted genus Iranocypris.

Distribution

Type locality: a flood resurgence at Kaaje‑Ru, near the oasis of Baq‑e‑Loveh, Lorestan Province, Zagros Mountains, Iran ( 33°04'39"N, 48°35'33"E.). This locality is 11 km from Tanh‑e‑kraft railway station on the line from Bendar Shapur to Tehran. This is also the type (and only known) locality of Garra lorestanensis and Eidinemacheilus smithi and the three species coexist. A second flooded cave is found 50m distant from the original and is likely an opening into the same phreatic cave. Known also from Tuveh Spring in the Dez River drainage 31km from the type locality (Vatandoust et al. 2019).

A report by Mahjoorazad and Coad (2009) suggests that G. typhlops has been collected in cave 130km distant from the type locailty, and that the species is distributed across the Zagros Mountains, should surely be dismissed. It is exceedingly unlikely that a single panmictic population of a subterranean fish could exist over such a huge area as karst terrains, and particularly the sink to resurgence flow paths, are highly fragmented. The null hypothesis for this second location is that it is an entirely separate species of Garra. The cave it was found in is no longer accessible. Mahjoorazad and Coad (2009) report that the fish at the remote location had a mental disk and if this is so it could not be G. typhlops which is without a disk (Figure a, below).

Habitat

The true habitat of this species is not known. The collection site is the flood overflow for a large resurgence. The resurgence was explored by diving (Farr 1977, 1984:117) but the way on underwater became too narrow at 2m depth. The flood overflow was also dived but without conclusion. Another sump is located in the same area but was not examined (Farr 1977).

Systematics

Garra typhlops is a member of the monophyletic group termed labeine cyprinids by Reid (1978, 1982). This comprises 13 genera defined by four synapomorphies. The cave restricted species Garra widdowsoni and Garra barreimiae are also members of this group. Howes (1991) places the labeine assemblage in the subfamily Cyprininae.

It has been known since 2008 (Sargeran et al. 2008) that some of the fishes at the type locailty have a mental disk while others do not (Figure a, below). Hashemzadeh Segherloo et al. (2012) used cytochrome c oxidase I (coI ) sequences for the two morphological forms. They concluded that "Pronounced coI sequence divergence between the two forms of I. typhlops (3·8% K2P distance) was observed. This sequence divergence is higher than the mean intraspecific divergence values reported in other taxa, e.g.0·46% in Lepidoptera, 0·60% in Guyanese bats, 0·27% in North American birds, 0·39% in marine fishes and 0·27% K2P distance in freshwater fishes. The high sequence divergence between the two forms, along with the morphological differences, including the presence of a mental disc, the longer intestine, and either a single chambered or bipartite swimbladder in the specimens with disc, v. the absence of the mental disc, shorter intestine and bipartite swimbladder in the second form, as reported by Sargeran et al. (2008), indicate that the two forms might represent separate species" (Hashemzadeh Segherloo et al. 2012). But they did not go so far as to state that two species were actually present nor to describe the second one. They also showed that the two cave forms are close to Garra rufa.

Farashi et al (2014), still assuming that the two forms were the same species (Iranocypris typhlops), used mitochondrial cytochrome b sequences and concluded that the species was close to the genus Garra and recommended that Iranaocypris typhlops should be transferred to the genus Garra Hamilton, 1822.

It was not until 2016 (Mousavi-Sabet and Eagderi 2016) that the second and most recently discovered form (the form with a mental disc) was described as a separate species to Garra typhlops. It was named Garra lorestanensis.

Most recently Hashemzadeh Segherloo et al. (2018), using a mixture of molecular markers, showed that G. typhlops and G. lorestanensis were sister species and that both were sister to the geographically close Garra gymnothorax. The evidence suggets that the two cave species evolved by sympatric speciation. A mitochondria divergence of 3.6% between the two cave species suggest a divergence time of 5-6 million years.

Zamani-Faradonbe et al. (2021) found a different topology. Their data make G. typhlops sister to a group containing G. tiam, G. meymehensis and G. gymnothorax. The sister to this group is G. lorestanensis.

Jalili and Eagderi (2014) examined the osteology of what they called Iranocypris typhlops (now Garra typhlops). However, the three specimens used in their study each had a mental disk so were, in fact, Garra lorestanensis.

Museum Holdings

As above plus: BMNH 1977.5.19:1, BMNH 1979.6.15:1-2. NMC uncatalogued 8 specimens (Brian Coad pers. comm.). VMFC GT01, VMFC GT02 to VMFC GT07, VMFC GT08 to VMFC GT10 (Mousavi-Sabet and Eagderi 2016).