Antarctic crabs rely on fuzz for food, not warmth
While animals like Emperor Penguins have famously adapted to living in the frigid climate of the Antarctic, it doesn’t mean they can take it easy. The extreme temperatures mean that while narrow spaces of habitability have been carved out, there’s likely little room for error or deviation before an animal imperils itself. The Hairy-Chested Yeti Crab (Kiwa tyleri) has just such a balancing act, except that it’s not just worried about the extreme cold— it also has to guard against extreme heat at the same time.
This tiny crabs, which range from 0.5 to 6 inches in length, live on the bottom of the ocean near hydrothermal vents. The vents pump heat the water nearby, up to 700° F if the crabs get too close to the vent itself. Between the vents’ heat and the near freezing water normally found 8,500 feet below the Antarctic ice, the yeti crabs are left with very little room to safely live. Because of this, they have been found maximizing the space that is habitable, generally piling on each other in a dense heap. They’ve even evolved short, stout front limbs to assist with climbing over their brethren and stay in the safe zone.
Such a narrow slice of land obviously limits the amount of scavenging or hunting a crab can do, which is ok because this crabs are farmers. The hair that covers their chest and arms attracts bacteria, meaning their food comes to them. This allows the crabs to more or less stay put.
Keeping the kids cold
A notable exception to this is that females have been seen further from the safe-zone pileup. Assuming some similarities to other related species, this frosty traveling is probably to assist the development of crab larvae, which want colder temperatures than the adults seek out. This comes at the cost of damage to the mother’s body though, and as such they probably only mate once in life to avoid repeated trips away from the warm and snuggly crab pile.
Source: New Species: Hairy-Chested Yeti Crab Found in Antarctica by Jason Bittel, National Geographic
