An Andrew's beaked whale <i>Mesoplodon bowdoini</i> (Cetacea, Ziphiidae) stranded on the Atlantic Coast of Uruguay

Abstract

On 24 May 2003, a fresh dead specimen of Andrew's beaked whale was found stranded at La Coronilla beach (33°54'50"S, 53°30'15"W), Department of Rocha, Uruguay. Morphological and osteological characters were used to identify the specimen and genetic analyses confirmed the species identification. Although basic body morphology was consistent with published descriptions, the Uruguayan specimen exhibited subadult characteristics, in spite of its total length (430cm), typical of an adult male. The color pattern differed from the previously described for a male of this species, being more similar to an adult female M. carlhubbsi. Its CBL (800mm) was beyond the reported range for the species (645-783mm), making it the largest known skull for M. bowdoini. The teeth were similar to those of an adult female M. bowdoini, being very small in relation to CBL and total length. Pulp cavity was partially closed and the crowns were erupted 9mm from the gum with no signs of wear. This study provides the first indication of accelerated growth in M. bowdoini and shows data on a specimen with an intermediate development status. The antorbital notch is more bulky and solid than the antorbital notches of New Zealand and Australian M. bowdoini. The jugal extended into the antorbital notch as occurs in most specimens and is more developed and more similar in form to that of M. carlhubbsi. This is the first occurrence of M. bowdoini on the Uruguayan coast and the northernmost record for the species in the Atlantic Ocean.