Challenging the cold: Crabs reconquer the antarctic

Abstract

Abstract. Recent records of lithodid crabs in deeper waters off the Antarctic continentalslope raised the question of the return of crabs to Antarctic waters, following their extinctionin the lower Miocene ;15 million years ago. Antarctic cooling may be responsible for theimpoverishment of the marine high Antarctic decapod fauna, presently comprising onlyfive benthic shrimp species. Effects of polar conditions on marine life, including loweredmetabolic rates and short seasonal food availability, are discussed as main evolutionarydriving forces shaping Antarctic diversity. In particular, planktotrophic larval stages shouldbe vulnerable to the mismatch of prolonged development and short periods of food availability,selecting against complex life cycles. We hypothesize that larval lecithotrophy andcold tolerance, as recently observed in Subantarctic lithodids, represent, together with otheradaptations in the adults, key features among the life-history adaptations of lithodids,potentially enabling them to conquer polar ecosystems. The return of benthic top predatorsto high Antarctic waters under conditions of climate change would considerably alter thebenthic communities.