Yeti crab cultivates food on its own arms

As reported by Ed Yong at Nature:

The yeti crab — so-called because of the hair-like bristles that cover its arms — is only the second of its family to be discovered... Writing in PLoS ONE this week, Thurber named the crab Kiwa puravida, after a common Costa Rican saying that means 'pure life'...

The bristles that cover the crab’s claws and body are coated in gardens of symbiotic bacteria, which derive energy from the inorganic gases of the seeps. The crab eats the bacteria, using comb-like mouthparts to harvest them from its bristles.

The bacteria in K. puravida gardens are closely related to species that live in other cold seeps and hot hydrothermal vents all over the world. “It looks like the bacteria may use the seeps as stepping stones, to create this global connected population that consumes the energy coming out of seeps and vents,” says Thurber.

Thurber thinks that K. puravida waves its claws to actively farm its bacterial gardens: movements stir up the water around the bacteria, ensuring that fresh supplies of oxygen and sulphide wash over them and helping them to grow.  “This 'dance' is extraordinary and comical,” says Van Dover. “We've never seen this strategy before.”

A brief, low-res video of the "dance" is at the link, along with additional details.  Not discussed there is these speculations from the Reddit thread:

If you wondered what kind of complex life can survive major asteroid impact, full-on nuclear winter and so on, remember the humble yeti crab and his bacterial garden. Where he goes, he does not need sun. Only methane seep in the deepest darkness. Cockroaches and even radioresistant-as-hell braconid wasps have nothing on him.

I imagine we would find life resembling this on Europa, if we're to ever look there.