#squat lobsters

The scientific name of this species is Kiwa hirsuta, but it's commonly known as the Yeti crab, thanks to its long, fuzzy forearms and pale appearance. It lives about 2,200 meters (roughly 7,200 feet) below the surface of the ocean, surviving in one of the most extreme environments on Earth: the hot, dark, methane-filled waters around deep-sea hydrothermal vents.

The Yeti crab's eyes are also greatly diminished, and they lack the structures that are necessary for sight, meaning that these creatures are completely blind.

The species was first discovered in 2005, and it belongs to a unique, previously-unknown taxonomic family that was given the name Kiwaidae, in reference to a Polynesian goddess associated with crustaceans. Over the course of the last 20 years, at least four other species have also been identified as members of family Kiwaidae. All of them live near deep-sea hydrothermal vents and cold seeps, and some have been known to form enormous colonies.

Above: hundreds of squat lobsters from family Kiwaidae living on hydrothermal vents along the Pacific-Antarctic ridge

The other members of family Kiwaidae also have patches of dense white bristles on their bodies, usually around their claws, legs, and/or bellies. Kiwa tyleri, another species from the same family, is commonly known as the Hoff crab, because its "hairy" chest reminded researchers of the actor David Hasselhoff.

Above: the Hoff crab

Information about this family is still scarce, but researchers believe that the Yeti crab is omnivorous, preying on mussels, shrimp, and algae. It also feeds on the epibiotic bacteria that grows in the "hairs" along its claws and legs (those "hairs" are actually hair-like structures known as setae).

According to this article:

The Yeti crab performs a fascinating dance, waving its arms in the water around deep-sea vents to cultivate its main source of food: bacteria. The movement brings fresh oxygen and nutrients to the bacterial colonies on the crab’s arms.

Scientists believe the Yeti crab grazes on these bacteria with its comb-like mouthparts, essentially farming its dinner.

The same feeding strategy has been observed in other members of family Kiwaidae, such as Kiwa puravida.

Above: Kiwa puravida on a methane seep in Costa Rica

The bacteria may help to filter out the natural toxins that are produced by hydrothermal vents -- especially the methane and sulphide, which the bacteria can process via chemosynthesis.

Sources & More Info:

Royal Society Publishing: The Yeti Crab

BBC Science Focus: What is a Yeti Crab?

Zoosystema: New Squat Lobster Family from the Hydrothermal Vents of the Pacific Antarctic Ridge

Oxford University Press: Deep-Sea Wildlife More Vulnerable to Extinction than First Thought

Ocean Info: Yeti Crabs

Baba's crinoid squat lobsters (Allogalathea babai) camouflage themselves in the midst of a feather star (Crinoidea) in Negros oriental, Philippines

Although they look like they belong on the runway, the elegant squat lobster's vivid coloration is actually a form of camoflage. These tiny crustaceans live on plant-like creatures called crinoids, or feather stars. Their hosts are brightly colored, so to blend in Allogalathea elegans pulls out all the stops!

Imagine if you could grow your own food right on your body- that’s what the yeti crab does! These deep-sea decapods wave their arms over hydrothermal vents to encourage bacteria growth, which they then feed on. Their long hairs are also used as sensory organs to find food like mussels.

(Image: A Hoff crab (Kiwa tyleri), named for David Hasselhoff, by David Shale)