BLAINVILLE'S BEAKED WHALE
Mesoplodon densirostris (Blainville 1817)

Order Cetacea : Family Ziphiidae

DESCRIPTION. A medium-sized whale that reaches lengths of 4.6–4.9 m and weighs about 1 metric ton. Slender in form; flippers short and set low on body; dorsal fin present; rostrum slender and pointed. Coloration dark gray to black dorsally and somewhat lighter ventrally; typically mottled with grayish scars left by parasites, squid sucker marks, and scratches incurred in intraspecific fighting. Males have a single large tooth at the midpoint of each side of the mandible. This tooth may be up to 20 cm in total length and is embedded in a large hump of supporting bone that gives a high, arching contour to the lower jaw. Females do not have so prominent a tooth and crested jaw.

DISTRIBUTION. These whales are uncommon residents of warm waters worldwide. In the western North Atlantic, they are rare but occur from Nova Scotia to Florida and the Gulf of Mexico. They are known in Texas on the basis of a single individual stranded on Padre Island on 29 February 1980.

SUBSPECIES. Monotypic species.

HABITS. Little natural history information is available for these rare and secretive whales. They are normally observed in small groups of three to six and are known to feed on squid.

Sounds recorded from a young male stranded in Florida were described as chirps and whistles. Sound spectrograms showed that at least some of the sounds were pulsed, indicating that echolocation by these whales may occur.

The reproductive habits of these whales are completely unknown.

POPULATOIN STATUS. Rare; strandings and observations. Only four verified stranding records of Blainville's beaked whale are available from the Gulf of Mexico. These are from the Mississippi–Alabama border, the Atchafalaya Bay area of Louisiana, Matagorda Bay along the Texas coast, and the panhandle of Florida. Two Blainville's beaked whales have been sighted in the northern Gulf of Mexico.

CONSERVATION STATUS. Although thought to be rare, no substantial population data exist for this unusual whale, and seasonal movements remain undocumented. Thus, it is difficult to determine Blainville's beaked whale's status in the Gulf of Mexico. It is not listed on any sort of endangered or threatened list by the federal government or by Texas. The IUCN listing is "data deficient" because of limited global population distribution and the lack of population trend information.

 

From The Mammals of Texas, Seventh Edition by David J. Schmidly and Robert D. Bradley, copyright © 1994, 2004, 2016.  Courtesy of the University of Texas Press.