IMPLICAÇÕES TAXONÔMICAS DO RECURSO “RAIA” NOS DESEMBARQUES DA PESCA COMERCIAL DE ARRASTO DE FUNDO NA PLATAFORMA CONTINENTAL SUL DO BRASIL

Taxonomic implications of the resource “ray” in commercial landings of bottom trawl fisheries in Southern Brazil

Abstract

A survey directed to the study of batoid species landed by the bottom trawl fishing fleet of Rio Grande - RS, Brazil, was carried out during the years 2001 to 2015. The aim of the study was to assess the diversity of the resource “rays” on the southern shelf of Brazil, an important area for reproduction of this group. The knowledge of the taxonomic structure of this group is crucial for conservation purposes. A total of 2360 specimens were recorded, of which 15 taxa were identified to species: Rioraja agassizii (n = 617; 26,1%), Sympterygia bonapartii (20,4%), Atlantoraja castelnaui (14,8%), Atlantoraja cyclophora (12,7%),  Zapteryx brevirostris (11,8%), Sympterygia acuta (4,4%), Atlantoraja platana (1,9%), Dasyatis hypostigma (1,4%), Pseudobatos horkelii (0,6%), Myliobatis goodei (0,5%), Gymnura altavela (0,3%), Psammobatis extenta (0,2%), Psammobatis rutrum (0,2%), Psammobatis lentiginosa (0,1%), and Myliobatis freminvillei (0,04%). There was a predominance of females (1258; 53,3%) over males (n = 666, 28,2%) and a considerable number of immature sizes (n = 545; 23,1%). Pair trawling was the most used trawl (82%) and was more likely to capture medium to large sized species.

Keywords: Biodiversity, By-catch, Species conservation, Elasmobranch, Overfishing.