Abstract

Espírito Santo State lies in a region of transition between tropical and subtropical benthic-algal floras; the region is considered to have the richest algal assemblage in the whole of Brazil. Extensive rhodolith beds cover much of the subtidal substratum in this area and host a diverse assemblage of frondose macrophytes. A detailed exploration at several localities has revealed many little-known and previously unreported taxa that are new to the southwestern Atlantic Ocean. In November 2004, the gelatinous rhodophytes Acrosymphyton caribaeum, Dudresnaya crassa, Naccaria corymbosa, Platoma sp. and Predaea feldmannii were discovered on rhodoliths at a depth of 18 m. Morphological and reproductive features of the species are provided here, with emphasis on post-fertilization events. The holotype of Platoma tenuis, originally described from Brazil, was examined and shown to be a species of Predaea. Acrosymphyton caribaeum hosted the epiphyte/endophyte Colaconema ophioglossum, and this also represents a new report from Brazil. This diverse community probably represents an ephemeral spring-summer element of the wider macroalgal flora.