TENTACULAR DIVERSITY IN DEEP-SEA DEPOSIT-FEEDING HOLOTHURIANS - IMPLICATIONS FOR BIODIVERSITY IN THE DEEP-SEA

The tentacles of deep-sea holothurians show a wide range of morphologi cal diversity. The present paper examines gross tentacle morphology in surface deposit feeding holothurians from a range of bathymetric dept hs. Species studied included the elasipods: Oneirophanta mutabilis, Ps ychropotes longicauda and Benthogone rosea and the aspidochirotids: Pa roriza prouhoi, Pseudostichopus sp., Bathyplotes natans and Paroriza p allens. The sympatric abyssal species Oneirophanta mutabilis, Psychrop otes longicauda and Pseudostichopus sp. show subtle differences in die t and the structure and filling patterns of the gut that suggest diffe rences in feeding strategies which may represent one mechanism to over come competition for food resources in an environment where nutrient r esources are considered to be, at least periodically, limiting. Inters pecific differences in tentacle functional morphology and digestive st rategies, which reflects taxonomic diversity could be explained in ter ms of Sanders' Stability-Time Hypothesis. Since different tentacle typ es will turn over sediments to different extents, their impact on sedi mentary communities will be enormous so that high diversity in meiofau nal communities may be explained most simply by Dayton and Hessler's B iological Disturbance Hypothesis.