Sistemática e Evolução - Comunicações orais

The family Scyliorhinidae (Carcharhiniformes) comprehends 38 species of sharks. The genus Scyliorhinus presents 16 valid species. However, the history of taxonomic rearrangements, along with gaps of information and sampling, led to disparities in identification and the consolidation of a good diagnosis of these species. Sharks from this genera usually do not exceed 600 mm TL and present a spot pattern that is mostly absent in their ventral region. Its body is dorsoventrally depressed and, unlike other genera, presents a projecting flap on the upper lip margin that covers the lower labial furrow. In addition, there is a great variety of color patterns, a significant taxonomic character. The species of Scyliorhinus occurs on the coasts of all continents, except for Antarctica, down to 800 m deep. The present work seeks to understand the relationships and distributions of Scyliorhinus at Brazilian Southeastern continental slope, focusing on S. haeckelii and S. cabofriensis. The material used in this study includes eight specimens (345–521 mm TL) collected by the DEEP-OCEAN project, on the continental slope off São Paulo and Santa Catarina States (27°26'60''W 47°28'61''S - 28°29'86''W 47°03'81''S) using bottom trawls. Additionally, five specimens from the didactic collection of Oceanographic Institute, University of São Paulo, were used for comparison. A total of 77 morphometric measurements were collected, seven of them showing a slight difference, mostly related to the pelvic fins and the fifth gill slit, along with three meristic data. While current studies suggest that S. haeckelii have more predominant spots with approximate bilateral symmetry compared to S. cabofriensis, this variation was not as prominent on the specimens analyzed. Prospective work includes sequencing of mitochondrial genes (COI) to further diagnose the specimens and to map the distribution of Scyliorhinus from the Western South Atlantic.