Anthropogenic impacts are an increasing threat to the diversity of fishes, especially in areas around large urban centres, and many effective conservation actions depend on accurate species identification. Considering the utility of DNA barcoding as a global system for species identification and discovery, this study aims to assemble a DNA barcode reference sequence library for marine fishes from the coastal region of São Paulo State, Brazil. The standard 652 bp 'barcode' fragment of the cytochrome c oxidase subunit I (COI) gene was PCR amplified and bidirectionally sequenced from 678 individuals belonging to 135 species. A neighbour-joining analysis revealed that this approach can unambiguously discriminate 97% of the species surveyed. Most species exhibited low intraspecific genetic distances (0.31%), about 43-fold less than the distance among species within a genus. Four species showed higher intraspecific divergences ranging from 2.2% to 7.6%, suggesting overlooked diversity. Notably, just one species-pair exhibited barcode divergences of <1%. This library is a first step to better know the molecular diversity of marine fish species from São Paulo, providing a basis for further studies of this fauna - extending the ability to identify these species from all life stages and even fragmentary remains, setting the stage for a better understanding of interactions among species, calibrating the estimations about species composition and richness in an ecosystem, and providing tools for authenticating bioproducts and monitoring illegal species exploitation.

Um levantamento preliminar da ictiofauna que ocorre na Estação Ecológica Serra Geral de Tocantins, situada no Sudeste do Estado do Tocantins e Noroeste do Estado da Bahia, é apresentado. A Estação Ecológica Serra Geral de Tocantins situa-se no divisor de águas entre as bacias do Rio São Francisco (Rio Sapão) e Rio Tocantins (bacias dos Rios Novo, Balsas e Manuel Alves). A cabeceira comum ou "água emendada" do Rio Sapão e Rio Galheiros, este um afluente do Rio Novo, situa-se no interior da estação e é considerada na literatura como uma possível área de intercâmbio ictiofaunístico entre a bacia do Rio São Francisco e a bacia do Rio Tocantins. Trinta e cinco espécies de peixes foram registradas dentro da Estação Ecológica Serra Geral de Tocantins e em seu entorno imediato, algumas delas desconhecidas da ciência e possivelmente endêmicas da região. Um total de 111 espécies de peixes foi registrado regionalmente (incluindo espécies de peixes registrados nos trechos do Rio Sapão e do Rio Novo/do Sono abaixo da estação). O acará Cichlasoma sanctifranciscense é aqui registrado pela primeira vez na bacia do Rio Tocantins. A ocorrência desta espécie, bem como do lambari Astyanax novae, no Rio Sapão e no Rio Novo/do Sono, são considerados os únicos exemplos inequívocos de transposição natural de espécies de peixes entre as bacias do Rio São Francisco e Tocantins efetuado pelas águas emendadas dos rios Sapão e Galheiros.

The sciaenid genus Bairdiella comprises a group of relatively small fishes found in inshore waters and estuaries of the western Atlantic and eastern Pacific. Despite recent analyses of the phylogenetic relationships of Bairdiella, there has been no comprehensive revision of the alpha taxonomy of the species of the genus. Bairdiella ronchus from the western Atlantic, has a complex taxonomic history, with four junior synonyms recognized. Based on morphological and molecular evidence, this study indicates that B. ronchus represents a species complex. The species is therefore redescribed and its geographic range is redefined. Bairdiella veraecrucis, which is currently recognized as a junior synonym of B. ronchus, is revalidated, and a new species of the genus is described from the Atlantic coast of Brazil. Finally, inferences are made on the diversity and biogeography of the B. ronchus species complex.

The Brazilian North coast is one of the world’s most important shrimp fishery grounds, with a total area of approximately 223,000 km2. However, the available data on the diversity of fish caught by the region’s industrial trawler fleet are limited to the commercially-valuable species. This lacuna in the data on the region’s marine fish fauna is worrying, both for the management of stocks and the conservation of the local biodiversity. The present study was based on a comprehensive inventory of the teleost fishes captured by the industrial outrigger trawling operations off the North coast of Brazil. This inventory recorded 201 species belonging to 64 families and 20 orders, and revealed a unique fauna, characterized by 17 endemic species, and a mixture of estuarine-dependent and marine species, mainly associated with coral reefs. The Kernel density analysis indicated that the industrial trawling fleet operates within an important ecotone, which encompasses the transition zones of different fish communities found off the Brazilian North coast.