Juvenile megamouth shark, Megachasma pelagios, caught off the Pacific coast of Mexico, and its significance to chondrichthyan diversity in Mexico

Abstract

On 16 November 2006, a female juvenile megamouth shark, Megachasma pelagios, was caught off the coast of Mexico in the Pacific Ocean, near Sebastián Vizcaíno Bay. This specimen, that has informally been referred to as “Megamouth No. 38”, measured 2265 mm in total length. It represents the third smallest female recorded for this taxon and the first report of M. pelagios off the Pacific coast of Mexico. The specimen is formally described here with basic anatomical data, and some aspects of this megamouth shark are compared with those of previously reported M. pelagios specimens. The occurrence near Sebastián Vizcaíno Bay is significant because it further emphasizes the high elasmobranch diversity in the area that should be regarded as a key region for shark conservation.