Mesophotic reeffish assemblages (30-90 m depth) of the small and remote St. Peter and St. Paul's Archipelago (SPSPA), Mid-Atlantic Ridge, Brazil, were characterized using remotely operated vehicles. Ordination analyses identified distinct fish assemblages in the upper (30-50 m) and lower (50-90 m) mesophotic zones, the former characterized by high abundances of species that are also abundant at euphotic reefs (Caranx lugubris, Melichthys niger, Stegastes sanctipauli and Chromis multilineata) and the latter dominated by two mesophotic specialists (Prognathodes obliquus and Chromis enchrysura). Planktivores dominated fish assemblages, particularly in the upper mesophotic zone, possibly due to a greater availability of zooplankton coming from the colder Equatorial Undercurrent in mesophotic depths of the SPSPA. Turf algae, fleshy macroalgae and scleractinian corals dominated benthic assemblages between 30 and 40 m depth, while bryozoans, black corals and sponges dominated between 40 and 90 m depth. Canonical correspondence analysis explained 74 % of the relationship between environmental characteristics (depth, benthic cover and complexity) and structure of fish assemblages, with depth as the most important independent variable. Juveniles of Bodianus insularis and adults of P. obliquus and C. enchrysura were clearly associated with branching black corals (Tanacetipathes spp.), suggesting that black corals play key ecological roles in lower mesophotic reefs

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Elasmobranchs are present in all aquatic ecosystems. They are dominant predators of the communities where they live and play an important role in the energy transfer among the upper trophic levels. The objective of this study was to understand the diet of stingray species found in the Biological Reserve of Parazinho (Amapá), to establish the type of food preferred by the group and by each species and the annual consumption of food items by the assemblages. Sampling was carried out from March 2012 to January 2013 by using longlines, inspected every falling tide, cast nets, jigs, and closing of tidal channels. For stomach content analysis, we used the food importance index (IAi). We analyzed 95 stomachs of stingrays of the following species:

The taxonomic status of Pomacentridae species can be difficult to determine, due to the high diversity, and in some cases, poorly understood characters, such as color patterns. Although Stegastes rocasensis, endemic to the Rocas atoll and Fernando de Noronha archipelago, and S. sanctipauli, endemic to the São Pedro and São Paulo archipelago, differ in color pattern, they exhibit similar morphological characters and largely overlapping counts of fin rays and lateral-line scales. Another nominal insular species, S. trindadensis, has recently been synonymized with S. fuscus but retained as a valid subspecies by some authors. Counts and morphometric analyses and mitochondrial DNA (COI, 16SrRNA, CytB) and nuclear DNA (rag1 and rhodopsin) comparisons of three insular species (S. rocasensis, S. sanctipauli and S. trindadensis) and three other South Atlantic species (S. fuscus, S. variabilis and S. pictus) were carried out in the present study. Analyses of the principal components obtained by traditional multivariate morphometry indicate that the species in general have similar body morphology. Molecular analyses revealed conspicuous similarity between S. rocasensis and S. sanctipauli and between S. trindadensis and S. fuscus and a clear divergence between S. variabilis from Northeast Brazil and S. variabilis from the Caribbean region. Our data suggest that S. sanctipauli is a synonym of S. rocasensis, support the synonymy of S. trindadensis with S. fuscus, and reveal the presence of a likely cryptic species in the Caribbean that has been confused historically with S. variabilis.

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