STRUCTURE AND DYNAMlCS OF A SHELF MHIPOD TAXOCOENOSIS IN SOUTHEASTERN BRAZIL

摘要

The distributional patterns ofamphipods were examined biaunually (summner and win- ter) at l8 sites located between l0 and l20 m in depth over the continental shelf of Sao Paulo State in southeastern Brazil. Multivariate analysis showed that water masses and sea depth, primarily and sediment texture, secondarily, are the factors structring the amphipod assemblages. Ordination analysis disclosed three distinct assemblages: (l) a coastal assemblage influenced by the coastal water; (2) an inner shelf assemblage influ- enced by a mixed zone with coastal water and south Atlantic central water; (3) an outer shelf assemblage within the south Atlantic central water domain. Species diversity which increased with depth, was related to environmental stability