Abstract This study compares local ecological knowledge (LEK) of fishers from the Southwest Atlantic Ocean (SWAO), Brazil, related to the franciscana dolphin (Pontoporia blainvillei). We conducted 330 ethnographic interviews in ten fishing communities in southern and southeastern Brazil between 2012 and 2018. Boolean or Classic Logic was used to identify 95 fishers who were able to recognize the franciscana dolphin accordingly to the taxonomic entity P. blainvillei: 23 in northern Espírito Santo state, one in southern Espírito Santo, 20 in northern Rio de Janeiro state, and 51 in northern Paraná state. Among these 95 fishers, 87.4% (n = 83) reported incidental captures in fishing nets. Among these, 52 (54.7%) did not know any solution to this problem. Interviews revealed that the fishers usually discard carcasses in the sea after fat and muscle tissue are removed so that they can be used as bait for shark fishing or as food. In Southeastern Brazil, fishers LEK related to their ability to identify franciscana dolphin varied from ‘no identification’ and ‘extremely low identification’ to ‘partial’ and ‘good identification,’ while in southern Brazil, fishers mainly presented a ‘good identification’ of the dolphins. We propose comanagement actions to conserve the franciscana dolphin in the SWAO.

Resumo Apesar de muitos estudos sobre a ictiofauna do Arquipélago de Fernando de Noronha terem sido realizados, sua diversidade de peixes mesofóticos nunca foi estudada antes. Neste estudo utilizamos mergulho autônomo e mergulho técnico, vídeos subaquáticos remotos com isca e veículo operado remotamente para registrar peixes de ecossistemas rasos (≤ 30 m de profundidade) e mesofóticos (31 a 150 m de profundidade). Dezenove espécies de peixes pertencentes a 14 famílias são apresentadas aqui como novos registros, representando um aumento de 8,2% na riqueza de peixes marinhos da região, que agora possui um total de 250 espécies e 77 famílias. Esses novos registros incluem quatro prováveis novas espécies e reforçam a importância de estudos em ecossistemas mesofóticos. Nossos resultados também enfatizam a necessidade de proteção e atenção à essa ictiofauna única encontrada nesses ecossistemas profundos.

Abstract Although several studies on the ichthyofauna of the Fernando de Noronha Archipelago have been carried out, its mesophotic fish diversity has never been surveyed before. Here we used SCUBA and technical rebreather diving, baited remote underwater videos and remotely operated vehicle to record shallow (≤ 30 m depth) and mesophotic (31 to 150 m depth) fishes. Nineteen fish species belonging to 14 families are reported here as new records, representing an increase of 8.2% in marine fish richness for the region, which now has a total of 250 species and 77 families. These new records include four potential new species and highlight the importance of surveying mesophotic ecosystems, even in well studied sites. Our results also emphasize the need for protection and attention to the unique ichthyofauna found at mesophotic depths.

The distribution, size structure, and feeding of three sea robin species belonging to the family Triglidae (Bellator brachychir, Prionotus nudigula and Prionotus punctatus) were studied based on specimens caught with bottom trawls on the continental shelf of Campos Basin, southeastern Brazil. The two Prionotus species were more concentrated in the inner shelf (<50 m), while B. brachychir was generally more abundant on the outer shelf (50-100 m). In general, the three species showed a carcinophagous diet, but with small overlap in their main preys. While amphipods was the most important prey to B. brachychir, isopods and shrimps were the basic food item found in P. nudigula and P. punctatus diet, respectively. This reduction in interspecific competition for food was followed by some degree of spatial segregation and thermal preferences for each species.

La distribución, estructura de tamaños, y la alimentación de tres especies de rubio pertenecientes a la familia Triglidae (Bellator brachychir, Prionotus nudigula y Prionotus punctatus) se estudiaron sobre la base de ejemplares capturados con redes de arrastre de fondo en la plataforma continental de la cuenca de Campos, en el sureste de Brasil. Las dos especies de Prionotus estaban más concentradas en la plataforma interior (<50 m), mientras que B. brachychir fue generalmente más abundante en la plataforma exterior (50-100 m). En general, las tres especies mostraron una dieta carcinófaga, pero con pequeño solapamiento en sus principales presas. Los anfípodos fueron la presa más importante de B. brachychir, los isópodos y camarones fueron el alimento básico encontrado en la dieta de P. nudigula y P. punctatus, respectivamente. Esta reducción de la competencia interespecífica por alimentos fue seguida por un cierto grado de segregación espacial y preferencias térmicas para cada especie.

Twenty-nine species from 11 genera of Myctophidae were taken in daytime midwater and bottom trawl hauls off eastern Brazil (11º-22ºS). Trawls were performed aboard the French R/V Thalassa to depths from 19 to 2271 m, including samples from shelf, slope and in the vicinity of oceanic banks and seamounts. Diaphus garmani was the most abundant species, accounting for 84% of all identified individuals and with four other species (D. dumerilii, D. brachycephalus, D. perspicillatus and Myctophum obtusirostre) accounted for >95% of all myctophids caught. Regarding longitudinal distribution patterns, 16 species are broadly tropical, seven tropical, three subtropical, two temperate and one amphi-Atlantic. For the most abundant and frequent species, highest abundances were associated mainly with cold waters, either South Atlantic Central Water or Antarctic Intermediate Water. Non-metric multidimensional scaling based on species presence-absence in the samples and oceanographic conditions was used to identify spatial distribution of myctophid assemblages. Three assemblages were identified in the studied area: north of Abrolhos Bank, south of Abrolhos Bank, and seamounts.

Veintenueve especies de 11 géneros pertenecientes a la familia Myctophidae fueron recolectados mediante faenas diurnas de arrastre de fondo y arrastre de mediagua en la costa oriental brasileña (11º-22ºS). Las faenas fueron realizadas con el buque oceanográfico Thalassa entre 19-2271 m de profundidad, cubriendo las regiones de la plataforma continental, talud, bancos oceánicos y montes submarinos. Diaphus garmani fue la especie más abundante (84%) y en conjunto con otras cuatro especies (D. dumerilii, D. brachycephalus, D. perspicillatus, Myctophum obtusirostre) representaron más del >95% de los mictófidos capturados. De acuerdo a los patrones de distribución longitudinal, 16 especies son de distribución tropical, siete tropical, tres son subtropicales, dos de zonas templadas y una anfi-Atlántica. Para las especies más abundantes y frecuentes, sus mayores abundancias estuvieron asociadas principalmente con aguas frías, especificamente con el Agua Central del Atlántico Sur y con el Agua Intermedia Antártica. Para definir la distribución espacial de las asociaciones de mictófidos basadas en la presencia y ausencia de las especies y su relación con las condiciones oceanográficas imperantes, se aplicó el análisis de ordenación MDS. Los resultados obtenidos indican la presencia de tres ensambles en el área de estudio: norte del Banco Abrolhos, sur del Banco Abrolhos y montes submarinos.