A species of deep-sea crab found in hydrothermal vents off Costa Rica cultivates “gardens” of bacteria on its claws to feed itself, reports Nature News.
Kiwa puravida, which is named after the common Costa Rican saying ‘pure life’, was discovered in 2006 by Andrew Thurber, a marine biologist now at Oregon State University, during a probe of oceanic methane seeps. The crabs were observed waving their claws over active seeps, which the researchers believe expose bacteria on their claws to fresh supplies of nutrients and oxygen. Nature News explains:
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…
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.
Since the bacteria derive their energy from methane and hydrogen sulphide gas, the K. puravida could be considered, albeit indirectly, a fossil-fuel powered crab.
The research is published this week in PLoS ONE.
CITATION: Thurber, A. R., Jones, W. J. & Schnabel, K. PLoS ONE. 6, e26243 (2011).