First report of the occurrence of false killer whale, Pseudorca crassidens (Cetacea:Delphinidae), at Ceará State, Brazil

Abstract

The false killer whale (Pseudorca crassidens) is a delphinid found in tropical and warm temperate waters around the globe. Its distribution is based in sightings and, mainly, in mass strandings. In Brazil, the species was recorded through strandings and incidental catches by fishing nets in the Southern (Rio Grande do Sul and Santa Catarina States), Southastern (Rio de Janeiro and Espírito Santo States) and Northeastern (Paraíba State) regions. This paper extends the geographical distribution range of this species in Brazil, following the stranding of a live specimen in Guajiru beach (130 km from Fortaleza), Ceará State, Northeastern region. Skull and morphometric measurements were conducted to identify the species. The animal, a 303 cm LT long young male, had an overall dark color pattern, except for the slightly lighter ventral region, characteristic for the species; slender pectoral fins, displayng a curvature similar to an “elbow” with sharp tips, falcate dorsal fin, with rounded tip; presence of 34 large dental alveoli; and a long and curved mouth. The animal showed disorientation, lack of balance, and altered respiratory frequency, dying a few hours after the stranding. Morfological and physiological, aspects, as well as the measurements obtained. Confirmed the identification of the species, extending its distribution for the Southwest Atlantic.