Oxyeleotris colasi is the first hypogean fish recorded from West Papua. The habitat consists of a freshwater pool in the cave of Jabuenggara located in the heart of Seraran anticline in the limestone karst of Lengguru. The new species is most closely related to the blind cave fish O. caeca described by Allen (1996) from eastern New Guinea. The two troglomorphic species are hypothesised to be related to O. fimbriata, an epigean freshwater gudgeon that ranges widely in New Guinea and northern Australia (Allen, 1996). Oxyeleotris colasi differs from its congeners by the absence of eyes, its skin and fins being totally depigmented, the presence of a well developed sensory papillae system partly consisting of low raised fleshy ridges on each side of the head, a reduced number of cephalic sensory pores, a reduced number of scales on head and body, a long head with a short snout length, a narrow mouth width and a long upper jaw length, body shape with a shallow anterior body depth and narrow body width, a long and deep caudal peduncle, long predorsal and prepectoral lengths, and a long pectoral fin