Taxonomy, reproduction and development of Dioptera neapolitana Delle Chiaje, 1841 (Onuphidae, Annelida)

Estudos taxonômicos foram conduzidos em onufídeos coletados na Baía do Araçá, em São Sebastião, litoral norte do estado de São Paulo, utilizando dados morfológicos e moleculares, e se confirmou que os espécimes coletados pertencem à espécie Diopatra neapolitana, originalmente descrita para o Golfo de Nápoles (Mar Mediterrâneo). Com a identidade específica dos animais confirmada, foi conduzido um estudo anual, com coletas mensais visando entender o ciclo reprodutivo a partir dos gametas femininos presentes no celoma, concluindo que, os indivíduos brasileiros possuem reprodução assíncrona, com o ciclo reprodutivo regido mais pelo tamanho de cada animal, do que pelos meses do ano. O estudo anual focou também na espermatogênese destes animais, que é caracterizada pela presença do citóforo, comum a outras espécies de poliquetas. Observou-se, entretanto, que a espermiogênese possui dois caminhos possíveis: formação de mórulas espermáticas e maturação do espermatozoide na própria estrutura unida pelo citóforo. Foi estudado o hermafroditismo sequencial desta espécie, caracterizado pelas papilas espermoducais, que para os indivíduos da Baía do Araçá, apresentam diferentes estágios de maturação, podendo representar as passagens de um gênero sexual para outro. Por fim foi estudado o desenvolvimento larval e dispersão de gametas, a partir de fertilizações in vitro, com registro de todos os estágios larvais para a espécie estudada, além da construção de protocolos importantes para a biologia do desenvolvimentoTaxonomic studies were conducted with onuphids collected at Araçá Bay, located in São Sebastião, in the northern coast of the state of São Paulo, using morphological and molecular data, and it is confirmed that these specimens belong to the species Diopatra neapolitana, which type locality is the Gulf of Napoli. After confirming the species identity, an annual study was conducted, with mensal collects of specimens, aiming to understand the reproductive cycle, based on feminine gametes present on each celom, and the conclusion is that for the Brazilian specimen, the reproduction is asynchronous, with the reproductive cycle guided rather by the size of each animal, than by the months. The annual study also focused on the spermatogenesis, which is characterized by the presence of the cytophore, common on other polychaete species, however, the spermiogenesis can be accomplished by two paths: formation of spermatic morulae or maturation of spermatozoa linked in the cytophore structure. The sequential hermaphroditism, characterized by the presence of spermoducal papillae, was also studied, and, for the specimen of the Araçá Bay, there are different maturation stages for this feature, probably related to the transition from one gender to another. Lastly, the larval development and gametes dispersion were studied, using in vitro> fertilizations, registering all larval stages for the present species, as well as the origination of development biology protocol

ABYSSAL Database: an integrated WebGIS platform for deep-sea information from the South Atlantic

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

Macrobenthic assemblages across deep-sea pockmarks and carbonate mounds at Santos Basin, SW Atlantic

The 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 deep-sea 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

Seep hunting in the Santos Basin, Southwest Atlantic: sampling strategy and employed methods of the multidisciplinary cruise BIOIL 1

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