Monday, April 1, 2013

[Crustacea • 2011] Kiwa puravida • Dancing for food in the deep sea: bacterial farming by a new species of yeti crab

Kiwa puravida holotype

Figure 1. Kiwa puravida holotype, in situ images, and morphologic and behavioral adaptations to harvesting its bacteria.
doi: 10.1371/journal.pone.0026243

Vent and seep animals harness chemosynthetic energy to thrive far from the sun's energy. While symbiont-derived energy fuels many taxa, vent crustaceans have remained an enigma; these shrimps, crabs, and barnacles possess a phylogenetically distinct group of chemosynthetic bacterial epibionts, yet the role of these bacteria has remained unclear. We test whether a new species of Yeti crab, which we describe as Kiwa puravida n. sp, farms the epibiotic bacteria that it grows on its chelipeds (claws), chelipeds that the crab waves in fluid escaping from a deep-sea methane seep. Lipid and isotope analyses provide evidence that epibiotic bacteria are the crab's main food source and K. puravida n. sp. has highly-modified setae (hairs) on its 3rd maxilliped (a mouth appendage) which it uses to harvest these bacteria. The ε- and γ- proteobacteria that this methane-seep species farms are closely related to hydrothermal-vent decapod epibionts. We hypothesize that this species waves its arm in reducing fluid to increase the productivity of its epibionts by removing boundary layers which may otherwise limit carbon fixation. The discovery of this new species, only the second within a family described in 2005, stresses how much remains undiscovered on our continental margins.

Etymology: Puravida, is a conjunction of the Spanish words “pura” and “vida” meaning pure life and is a common saying within Costa Rica, in whose waters these specimens were collected in. The genus is feminine as is the species name.

Figure 4. Kiwa puravida male holotype,

Andrew R. Thurber, William J. Jones & Kareen Schnabel. 2011. Dancing for food in the deep sea: bacterial farming by a new species of yeti crab. PLoS ONE. 6 (11): e26243. doi: 10.1371/journal.pone.0026243.