Pelagic cnidarian assemblages show range-edge effect at the boundary of ocean surface, as illustrated in the case of the Amazon River Plume.

The neuston layer represents a complex community inhabiting the interface where oceanographic and atmospheric processes interact. Here, our aim was to compare patterns in the distribution and abundance of cnidarian assemblages observed in the neuston to parallel patterns previously observed in epipelagic waters along the spread of the Amazon River Plume over the Western Equatorial Atlantic, to test if the neuston reflects the patterns of the overall community whose core of distribution is located in epipelagic waters or are shaped by specific surface processes. The results show that both initial hypothesis were false.

The Amazon River plume, a barrier to animal dispersal in the Western Tropical Atlantic.

The dispersal of marine organisms can be restricted by a set of isolation mechanisms including hard barriers or hydrological features. In the Western Atlantic Ocean, the Amazon River discharge has been shown to act as a biogeographical barrier responsible for the differences in reef fish communities between Caribbean Sea and Northeast Brazil continental shelves. Here, we compare the diversity of all Animalia phyla from biogeographic ecoregions along the Tropical Western Atlantic continental shelf to test the hypothesis that the Amazon River plume spatially structures species diversity.

Short-term variation of plankton spatial distribution at a subtropical mixed estuarine system.

The horizontal distribution of plankton communities in a subtropical mixed estuarine system over one tidal cycle was investigated. Hydrological and planktonic samples were obtained twice on 17 July 2007 in a transect with ten stations in the Babitonga Bay estuary, south Brazil (~26°S). Hydrological variables did not vary spatially or tidally during samplings.

Teissiera polypofera: first record of the genus Teissiera (Hydrozoa: Anthoathecata) in the Atlantic Ocean.

Specimens of Teissiera polypofera Xu, Huang & Chen, 1991 were found in waters off the northeast Brazilian coast between 8.858°S, 34.809°W and 9.

Foraminiferal assemblage structure from Brazilian tropical urbanized beaches (~7°S).

Foraminifera are diversified protists with high ecological and bioindicator importance. Physical-chemical parameters of the environment can be evaluated through the taphonomic analysis of the test coloring, because once they settle in the sediment their tests begin to behave as sedimentary particles. Five urbanized tropical Brazilian beaches were sampled in this study in order to characterize the diversity, abundance, taxonomic and taphonomic structure of Foraminifera assemblages.

Ingestion of microplastic by ontogenetic phases of Stellifer brasiliensis (Perciformes, Sciaenidae) from the surf zone of tropical beaches.

Microplastics (<5 mm) are present in marine ecosystems worldwide where they can be ingested by a wide range of organisms from different trophic levels. In this study we analyzed the gastrointestinal tract of 443 specimens of Stellifer brasiliensis (124 juveniles, 254 subadults, and 65 adults) sampled in tropical beaches adjacent to the Paraíba River estuary. We found 1-3 microplastics in 42 fishes (9.

New species of Grubeulepis Pettibone, 1969 (Eulepethidae, Annelida) from northern Brazil.

Eulepethidae is one of the least diverse families of scale polychaetes, with only 23 species described thus far. In this study we describe an additional species of Grubeulepis from unconsolidated substrata from Maranhão, tropical Brazil (ca. 2°S).

Census of Cnidaria (Medusozoa) and Ctenophora from South American marine waters.

We have compiled available records in the literature for medusozoan cnidarians and ctenophores of South America. New records of species are also included. Each entry (i.

Diel Vertical Dynamics of Gelatinous Zooplankton (Cnidaria, Ctenophora and Thaliacea) in a Subtropical Stratified Ecosystem (South Brazilian Bight).

The diel vertical dynamics of gelatinous zooplankton in physically stratified conditions over the 100-m isobath (~110 km offshore) in the South Brazilian Bight (26°45'S; 47°33'W) and the relationship to hydrography and food availability were analyzed by sampling every six hours over two consecutive days. Zooplankton samples were taken in three depth strata, following the vertical structure of the water column, with cold waters between 17 and 13.1°C, influenced by the South Atlantic Central Water (SACW) in the lower layer (>70 m); warm (>20°C) Tropical Water in the upper 40 m; and an intermediate thermocline with a deep chlorophyll-a maximum layer (0.

Faunistic survey of Hydromedusae (Cnidaria, Medusozoa) from the coast of Paraná State, Southern Brazil.

This study is the first faunistic inventory of hydromedusae from the inner continental shelf of Paraná State. We describe the composition of hydromedusae species, collected with bottom-trawl and Hensen nets, in campaigns carried out from 1997 to 2006. We analyzed 17,797 specimens from 578 samples, and provide descriptions, photographs, and information about the biology of the 22 species found.