Behavioural study of two Hydrothermal crustacean decapods: Mirocaris fortunata and Segonzacia mesatlantica, from the lucky strike vent field (mid-Atlantic ridge)

摘要: Abstract Identifying the factors driving community dynamics in hydrothermal vent communities, and particular biological interactions, is challenged by our ability to make direct observations difficulty conduct experiments those remote ecosystems. As a result, we have very limited knowledge on species׳ behaviour interactions these communities how they turn influence dynamics. Interactions such as competition or predation significantly affect structure video time-series successfully been used gain insights species behaviour, including responses short-term changes temperature feeding strategies. In this study, combined situ ex approaches characterise among two key encountered along Mid-Atlantic Ridge (MAR): shrimp Mirocaris fortunata crab Segonzacia mesatlantica. situ, small-scale distribution, were studied using TEMPO observatory module deployed seafloor at base of active Eiffel Tower edifice Lucky Strike field part EMSO-Acores MoMAR observatory. sampled 2 min four times day from July 2011 April 2012. One week per month was for ‘long-term’ variations, full data set analysed January addition, individuals maintained first time under controlled conditions atmospheric pressure (classic tank) pressurised (AbyssBox) aquaria allowed better characterisation description different types observed nature. While identified spatial distribution pattern stable over nine months, both displayed significant preference mussel bed anhydrite substrata, preferentially occupied area located directly fluid flow axis. The aggregation M. resulted occurrence numerous intraspecific mainly involving use pairs sensory organs (antenna/antennule) fleeing behaviours when contact close S. higher level passiveness artificial environment compared attributed lack stimulation related low densities congeners and/or sympatric natural absence continuous food supply, activity during time. This result emphasises role supply driver behaviour. Direct cameras deep-sea observatories, with experimental set-up aquaria, will help investigators understand influencing biology vents well their underlying mechanisms.