Pacific bluefin tuna ( <i>Thunnus orientalis</i> ) bycatch in the Atlantic Ocean

A large tuna was hooked by a Japanese longline fishery in the high seas near the Republic of Namibia. This fishing ground is mainly utilized for Thunnus albacares, Thunnus obesus and Thunnus alalunga by Japanese tuna longliners. Because the tuna was larger than the common size of these species, the specimen was sampled for genetic species identification and morphological measurements. The fish, which weighed 107 kg without gills and gut, was unexpectedly identified as Thunnus orientalis by a thorough analysis of morphology, mitochondrial genes and nuclear single-nucleotide polymorphisms.