Kingdom Animalia Class Actinopterygii Family Eleotridae Rank Species | Phylum Chordata Order Perciformes Genus Typhleotris | |
Similar Typhleotris, Typhleotris madagascariensis, Glossogobius ankaranensis, Milyeringa veritas, Spinycheek sleepers | ||
Typhleotris mararybe is a species of fish in the family Eleotridae, the sleeper gobies. It is a troglobitic species endemic to cave habitat in Madagascar. It is unique among known cave-dwelling fish in that is both blind and darkly pigmented. It has well-developed nonvisual sensory systems and dives to avoid approaching objects. The fish was first collected in 2008 and was described to science as a new species in 2012.
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Description
T. 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.
Habitat
Typhleotris mararybe is one of four cave-dwelling fishes in Madagascar. It is known from a single cave, a karst sinkhole called the Grotte de Vitane near Itampolo, where two specimens were collected. The species is probably endangered, but it has not been classified by the IUCN.
Taxonomic evaluation
T. mararybe was described from the two specimens, the holotype and the paratype, in 2012. It was published in American Museum Novitates, a journal of the American Museum of Natural History. Locals sometimes enter the cave, but were unaware of the species.
The specific name was derived from the Malagasy words marary (ill or sick), and be (big), combined to mean "very sick" or "big sickness". It commemorates an unknown severe illness suffered by members of the field team after their snorkeling expedition to survey the sinkhole.