Despite a strong increase in research on seamounts and oceanic islands ecology and biogeography, many basic aspects of their biodiversity are still unknown. In the southwestern Atlantic, the Vitória-Trindade Seamount Chain (VTC) extends ca. 1,200 km offshore the Brazilian continental shelf, from the Vitória seamount to the oceanic islands of Trindade and Martin Vaz. For a long time, most of the biological information available regarded its islands. Our study presents and analyzes an extensive database on the VTC fish biodiversity, built on data compiled from literature and recent scientific expeditions that assessed both shallow to mesophotic environments. A total of 273 species were recorded, 211 of which occur on seamounts and 173 at the islands. New records for seamounts or islands include 191 reef fish species and 64 depth range extensions. The structure of fish assemblages was similar between islands and seamounts, not differing in species geographic distribution, trophic composition, or spawning strategies. Main differences were related to endemism, higher at the islands, and to the number of endangered species, higher at the seamounts. Since unregulated fishing activities are common in the region, and mining activities are expected to drastically increase in the near future (carbonates on seamount summits and metals on slopes), this unique biodiversity needs urgent attention and management.

The age and growth of the snowy grouper, Epinephelus niveatus, from central and south-eastern Brazil were studied by otolith analysis from a sample of 341 specimens, ranging from 325 to 1216 mm in total length (TL) caught with bottom longlines between 1996 and 1998. Otolith length grew proportionally with the increasing TL of the fish. Marginal increment analysis indicated that a single opaque band forms each year during autumn–winter. The maximum estimated age was 54 years, which significantly extends the previously estimated life-span of 21–29 years for this species. The von Bertalanffy growth parameters for both sexes were estimated as L∞ = 1098.4 mm TL, K = 0.062 year −1 and t0 = –2.68. The study revealed differences in mean length-at-age and size at recruitment, as well as in growth parameters between the central and the south-eastern Brazilian coast, which can be attributed mainly to different fishing pressures. The snowy grouper was found at depths of 82–492 m, and showed a positive relationship between age and depth, suggesting differential movements of older fish to deeper waters.

Recent pelagic and benthic trawling activities over the Brazilian continental slope between 11° and 23°S captured nine species representing five genera of the stomiiform family Sternoptychidae. Among these, three species are new records for Brazilian waters: Sternoptyx pseudodiaphana, Argyripnus atlanticus, and Polyipnus sp. The known distributions of Argyropelecus aculeatus and Maurolicus stehmanni along the Brazilian coast are extended northward to 13°S and 16°S, respectively, while that of Sternoptyx diaphana is extended southward to 13°S. Argyropelecus hemigymnus, Argyropelecus sladeni, and Sternoptyx pseudobscura were rarely caught (n=2–16). A key to the western South Atlantic species of Sternoptychidae is provided.

New collections made by the French research vessel Thalassa and the Brazilian Astro Garoupa on the Brazilian continental slope, between 11° and 23° S revealed a great diversity of deep-sea gadiforms obtained between 200 and 2270 m. Of the 34 species collected, 13 (38%) are being reported for the first time in the western South Atlantic and one may represent a new species. The most species-rich family in the area is Macrouridae (25 species), followed by Moridae (4), Phycidae (2), Merlucciidae (2), and Bregmacerotidae (1). Most of the species collected is also found in the Gulf of Mexico and Caribbean and have their known ranges of distribution extended into the tropical waters of central Brazil. Four species typically occur in temperate waters and were found only in the southernmost stations. A summary comparison of the bathymetric distributions of each species on the slope is provided.

The myctophid Diaphus adenomus is recorded for the first time in the South Atlantic Ocean based on 139 specimens (83-203 mm standard length) collected from eight trawl stations off eastern Brazil, between 13 and 16°S at 38 and 39°W, at depths from 233 to 1275 m. #