Typhleotris mararybe

Typhleotris mararybe is about 38 mm (1.5 in) long. The body is uniformly dark brown in color, and the fins are mostly white with brown bases. Its sensory systems include a series of pores on its head, but it lacks eyes. The fish is relatively slow-moving, but more responsive to approaching objects than the closely related T. madagascariensis, diving to avoid them. It can be distinguished from other members of genus Typhleotris by its dark pigmentation and aspects of its bone structure. T. mararybe is possibly the sister species of T. madagascariensis, as the two share characteristics in common that T. pauliani, the only other member of the genus, does not. T. mararybe may have evolved from an ancestral species that lacked pigmentation and was blind, but that pigmentation was regained for camouflage in parts of the cave that receive sunlight.

Typhleotris mararybe is one of four cave-dwelling fishes in Madagascar. It was initially known from only a single cave, a karst sinkhole called the Grotte de Vitane near Itampolo, where two specimens were collected, but has later been discovered to occur in four additional sinkholes/caves in the region. It is overall less widespread and common than T. madagascariensis, which also occurs in the five caves/sinkholes inhabited by T. mararybe. Despite this, direct competition between the two species is not known.