When a team of research divers entered a sinkhole in southwestern Madagascar, they started to feel ill. They were suffering from "sinkhole fever," a debilitating viral fever. It turns out that a newly discovered species of fish was the culprit.
Researchers named it the Typhleotris mararybe, meaning "big sickness" to acknowledge its effect. The sinkhole is considered a sacred spot, where locals come to offer prayers, according to The Guardian.
The cave fish lives in perpetual darkness. About 38 millimeters long and lacking eyes, it features enhanced non-visual sensory tools such as canals and pores on its head. Its murky brown pigmentation would easily allow it to blend into a riverbed.
There are more than 150 types of cave fish, but this is the first time this particular species has been identified. According to the Guardian, the four cave fish species known to exist in Madagascar are gobioids, but they come from two different evolutionary lineages.