AMPHIPOD CRUSTACEANS FROM HYDROTHERMAL VENTS - PRESENT KNOWLEDGE

Since 1989 several works were devoted to Crustacea Amphipoda collected in hydrothermal vents. Twenty six species have been identified and de scribed by different authors. Some of them are strictly linked to the hydrothermal vents communities, others are active necrophages with lar ger distribution. The present work attempts to undertake a most comple te census and to be as precise as possible in distinguishing species h arvested in the proximity of fluid emissions or associated with the ot her organisms living around hydrothermal sites or in the surrounding r egion for both Pacific and Atlantic sites. The number of endemic speci es is high but it is evident that the studied material is often reduce d and only a small number of species has been found at multiple sites. Eleven families of gammaridean amphipods have so far been found, amon g those Lysianassidae are particularly well represented, especially in the Pacific. Clouds of pardaliscid amphipods and the extreme abundanc e of the lysianassid Ventiella sulfuris seem to be strictly limited to sites in the Pacific. Atlantic sites do not seem to present the same trophic structures. Our present knowledge indicates the Atlantic sites seem less rich than the Pacific in both number of species and individ uals.