No abstract

Members of one species of Leodice Lamarck, 1818, one species of Lysidice Lamarck, 1818, and another of Palola Gray in Stair, 1847 were found among material from rhodolith beds, collected off the states of Paraíba and Pernambuco, northeastern Brazilian coast. Of those species, one is new to science and the other two are new records for the state of Pernambuco, although their occurrence on neighbouring areas was already known. Leodice calcaricola sp. nov. resembles morphologically L. miurai (Carrera-Parra & Salazar-Vallejo, 1998) as members of both species share similar body size, moniliform prostomial appendages, similar numbers of branchial filaments (1–3 per branchia), and, especially, by having falcigers with bidentate blades on anterior chaetigers, and tridentate on posterior ones. These species differ, however, since specimens of L. calcaricola sp. nov. have distinctly shorter antennae and palps, homodont and heterodont pectinate chaetae, three types of aciculae and two subacicular hooks per midbody parapodium. The other two species which members were found on the rhodolith beds are Lysidice cf. unicornis (Grube, 1840) and Palola brasiliensis Zanol, Paiva & Attolini, 2000. We describe herein new species to science and provide a redescription for L. cf. unicornis because the Brazilian specimens of this species have never been formally described.

Ocean and Coastal ResearchThe SE Brazilian continental margin is rich in geomorphological features that create different seascapes, where diverse benthic communities thrive. The seafloor is composed of a mixture of pockmarks of different sizes and shapes and tall carbonate mounds that may form extensive chains. Mounds are colonized by deep-water corals which are the main responsible organisms promoting growth over geological time. Depressions and mounds affect the benthic ecosystem in multiple ways owing to water flow, sedimentation rates and food availability. This paper presents new data on macrofaunal composition and community structure associated with deep-sea coral habitats and pockmark areas along the upper continental slope of Santos Basin. Ten sites were sampled using a 0.25 m2 box corer on board R/V Alpha-Crucis, totaling 27 sediment samples. A total of 182 taxa were found, including new records for the Southwestern Atlantic, as well as several potential new species to science. In general, we observed an association of the macrobenthic fauna with the geomorphology of the area and the most important variables, mainly substrate composition and water flux. The abundance, taxonomic composition and also the feeding modes varied across the deep-water coral sites and pockmarks, reflecting in a mosaic of benthic habitats. As deepsea corals and pockmarks are extremely sensitive to anthropogenic influence and natural shifts, in addition to the economic value associated to fisheries, this study provides baseline information on these special habitats in Santos Basin that can be used for future research, monitoring activities, and conservation strategies.

South Atlantic deep waters provide a huge diversity of habitats, with variations in areas such as geology, macrofauna, microbiology, physics, and chemistry. However, most of the data lacks central organization, important for subsequent deep-sea research, especially considering the multidisciplinary approaches and comparisons of the South Atlantic with other oceanic basins. Given the rising interest in commercial exploration off the deep-sea, especially with respect to hydrocarbon extraction and mining, there is an urgent need for a centralized repository of information with tools to collect and share geospatial data to support the conservation of this important oceanographic region. The main objective of this manuscript is to present an integrative database in WebGIS format for South Atlantic deep waters, open to further development in terms of data input, reliant on researcher collaboration, and with tools for ongoing maintenance and usability improvement driven by user feedback. The WebGIS format provides an open access, cost-free, feature-rich, and easy to use database through any Internet browser to reach the greatest number of researchers and students possible. The ABYSSAL database can be accessed at http://abyssal.io.usp.br.

The continental margin off the southeastern Brazilian coast is punctuated by a series of geological-geomorphological features, such as subsurface saline diapirs and pockmarks at the seafloor interface, which evidence the abundant presence of oil and gas in the region. In several of these sites, hydrocarbons can be naturally released into the water column, areas are cold seep areas. These are marked by the presence of oil- and gas-dependent ecosystems, where specific organisms are able to fix carbon from hydrocarbon chemosynthesis. In addition, light hydrocarbon fluid flow through the sediment may build up authigenic carbonates that can be further colonized by cold-water corals, generating large carbonate mounds over geological time, normally positioned at the border of these pockmark features. The present work reports on a multidisciplinary oceanographic cruise carried out in the Santos Basin, SW Atlantic, to seek, map, and collect geological, chemical, and biological data from different deep-sea habitats. The cruise occurred in November 2019 on the R/V Alpha Crucis of the Oceanographic Institute of the University of São Paulo (IOUSP). We intended to discover and detail different geomorphological features, characterize free-living and symbiotic microorganisms, determine the chemosynthetic rates in relation to heterotrophic microbial production, and characterize the fauna and study their ecological and evolutionary links within and across ocean basins. All discoveries made during the cruise and their respective results will be presented separately in several papers that comprise this special volume.