The scarcity of fresh water habitats in the United Arab Emirates and Oman limits the number and variety of fish that are found there, with the Omani blind cave fish being the most common and widespread of the very few native fish species (2) (3). Small and dark in colour, the Omani blind cave fish is typically mottled brown, sometimes with more colourful red, white or blue markings in larger adults (2) (3), and has a thin, pale transverse line just behind the head, appearing to demarcate the head from the body. The body is relatively long, with a rather flat underside, and the head is wedge-shaped, with a blunt snout (2) and a specialised mouth plate on the underside, which acts as a suction device (2) (3). The scales are large and heavy (2).
Three subspecies of Omani blind cave fish have been suggested, Garra barreimiae barreimiae, G. b. shawkahensis and G. b. gallagheri (2) (3) (4), and a fourth, smaller subspecies, G. b. wurayahi, has also been proposed (4). Most notable, though, is the discovery in 1980 of a distinct cave-dwelling population which, like other cave-dwelling fish, is distinguished from its surface-dwelling relatives by its lack of pigmentation, decreased scales, and by the lack of externally visible eyes (5) (6) (7) (8), which leads to the species’ common name. In this cave-dwelling population, eyes are present in juveniles, but become covered in older fish, although individuals artificially exposed to light show increased development of the optic lobe in the brain (5) (6) (7).
- Length: up to 8 cm (2)