Wax-ester reserves facilitate dispersal of hydrothermal vent shrimps

Late zoeal and early postlarval stages of vent s h n m p (Rimcans exoculata, Chorocans chacei and Alvlnocarls rnarkensls), sampled from the water column above the Broken Spur vent site (mid-Atlantic Ridge), contained large amounts of bright orange coloured lipid in their thoracic and abdominal regions.The lipid compnsed 75 to 8 2 % wax ester, containing predominantly 16:O and 18:l fatty alcohols.In contrast, wax esters were found to be absent in samples of adult vent shrimp (R. exoculata and A. markensis) Substantial wax-ester reserves are a recognised adaptation to a prolonged bathypelagic, planktotrophic existence in deep-sea organisms where food is scarce and they have to survive extended periods without feeding This characterist~c is clearly of benefit to larval vent shnmp, which appear to be the main dispersal phase in the llfe history of these organisms, whose adult stages inhabit a stnkingly ephemeral environment whlch is discontinuous in both space and time.