Layard's Beaked Whale

Taxobox
name = Layard's Beaked Whale
status = DD
status_system = iucn2.3

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image2_caption = Size comparison against an average human
regnum = Animalia
phylum = Chordata
classis = Mammalia
ordo = Cetacea
subordo = Odontoceti
familia = Ziphidae
genus = "Mesoplodon"
species = "M. layardii"
binomial = "Mesoplodon layardii"
binomial_authority = Gray, 1865
range_

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range_map_caption = Layard's Beaked Whale range

Layard's Beaked Whale ("Mesoplodon layardii"), also known as the Strap-toothed Whale or the Long-toothed whale is a large Mesoplodont with some of the most bizarre teeth of any mammal. The common and scientific name was given in honor of Edgar Leopold Layard, the curator of the South African Museum who wrote an initial description of a skull.

Description

The overall body shape of Layard's Beaked Whale is fairly typical for a Mesoplodont, except for the large size. Male specimens have large and peculiar teeth even for the genus, they are large straps, sometimes over 30 centimeters (1 foot) in length, which grow over the jaw at a 45 degree angle and nearly close it. The teeth also have dorsally projecting denticles, and are still apparently used for fighting. Barnacles quite frequently are found on the teeth as well. It is quite uncertain why the species would grow teeth that severely cut back on the size of prey it can consume. The melon on the whale is somewhat bulbous, and blends in to the beak shortly before the strap teeth. The beak itself is fairly long with a relatively straight mouthline. The coloration of this species is also unusual for a Mesoplodont since it is rather bold, most of the body is black except for a white areas on the front of the beak, the throat, an area behind the head in a shape reminiscent of a cape, and near the genitals. Juveniles do not have this coloration and are typically dark above and light below. Scars and cookie cutter shark bites are also present. Males can reach around 5.9 meters (19 feet 6 inches) whereas females reach 6.2 meters (20 feet) and likely weigh around 1000-1300 kilograms (2200-2900 pounds). This indicates that they are probably the largest species in the genus. Newborn calves may get up to 2.8 meters (9 feet) in length.

Population and distribution

This species inhabits the Southern Hemisphere, judging by the numerous strandings and infrequent sightings. No population estimates have been made.

Behavior

Nothing is known about social organization, and this species is a squid eater. Males have a gape half the size of females and juveniles, limiting their squid to those weighting 100 grams (3.5 ounces) and less.

Conservation

This species has never been hunted or entangled in fishing gear. It is believed to be in a rather safe position compared with other Mesoplodonts.

References

*
*"Encyclopedia of Marine Mammals". Edited by William F. Perrin, Bernd Wursig, and J.G.M Thewissen. Academic Press, 2002. ISBN 0-12-551340-2
*"Sea Mammals of the World". Written by Randall R. Reeves, Brent S. Steward, Phillip J. Clapham, and James A. Owell. A & C Black, London, 2002. ISBN 0-7136-6334-0

External links

* [http://www.teara.govt.nz/EarthSeaAndSky/SeaLife/Whales/7/ENZ-Resources/Standard/1/en photo of skull of straptoothed whale]
* [http://www.amonline.net.au/factsheets/strap_toothed.htm Factsheets]
* [http://www.sci.tamucc.edu/tmmsn/29Species/MoreSpec/straptoothedwhale.html Cetaceans of the World]
* [http://www.cms.int/reports/small_cetaceans/data/m_layardii/m_layardii.htm CMS]
* [http://www.wdcs.org Whale & Dolphin Conservation Society (WDCS)]