Kiwa (crustacean)

Kiwa is a genus of marine decapods living at deep-sea hydrothermal vents and cold seeps. The animals are commonly referred to as yeti lobsters or yeti crabs, after the legendary yeti, because of their "hairy" and bristly appearance. The genus Kiwa is named after the god of shellfish in Polynesian mythology. The genus is placed in its own family, Kiwaidae, in the superfamily Chirostyloidea.

Based on the presence of sulphur-oxidising bacteria on the "hairs" (properly known as setae) of both K. hirsuta and the new South West Indian Ridge species, they may both feed on bacteria in addition to scavenging. Some of this bacteria is found in the bristles of their claws, which are believed to have been cultivated intentionally for consumption. For K. puravida, the bacteria have been identified and the feeding behaviour observed, as well as a cyclical rhythmic motion of the crab documented that is suspected to increase the flow of methane and hydrogen sulfide, the bacterial food, towards the bacteria. The two sexes of the new South West Indian Ridge species prefer different temperatures, with males seeming to prefer warmer water and egg-carrying females and juveniles preferring the coldest.

Because yeti crabs live in extreme environments like cold seeps and hydrothermal vents, the species has adapted certain behaviors and qualities to aid their survival. These adaptations include the growth of setae, propodus and claws. The internal anatomy, diet, behaviors and adaptations of the yeti crab are outlined below.