Layard's Beaked Whale
Encyclopedia
The strap-toothed whale (Mesoplodon layardii), also known as the Layard's beaked 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 prepared drawings of a skull and sent them to the British
taxonomist John Edward Gray
, who described the species in 1865.
s quite frequently are found on the teeth, as well. Why the species would grow teeth that severely cut back on the size of prey it can consume is quite uncertain. The melon 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 metres (19 feet 6 inches), whereas females reach 6.2 metres (20 feet) and likely weigh around 1000-1300 kilograms (2200-2900 pounds), indicating they are probably the largest species in the genus. Newborn calves may be up to 2.8 metres (9 feet) in length.
between 30° S and the Antarctic Convergence
. It may occur south of 38° S year-round moving north of 38° S seasonally. As of 1991, there are about 140 records (nearly all strandings) of this species from New Zealand
(50, including one sighting), Australia
(over 40), southern Africa
(about 40), southern Argentina
and Tierra del Fuego
(10), southern Chile
(4), Falkland Islands
(3), and Uruguay
(1). Strandings have also been reported from Heard Island, the Kerguelen Islands
, and Brazil
. More recently one individual was seen breaching between the South Orkney Islands
and South Georgia
.
Edgar Leopold Layard
Edgar Leopold Layard CMG, FZS, MBOU was a British naturalist mainly interested in ornithology. Born in Florence, Italy, to a family of Huguenot descent, he was the sixth son of Henry Peter John Layard of the Ceylon Civil Service with his wife Marianne,...
, the curator of the South African Museum who prepared drawings of a skull and sent them to the British
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
taxonomist John Edward Gray
John Edward Gray
John Edward Gray, FRS was a British zoologist. He was the elder brother of George Robert Gray and son of the pharmacologist and botanist Samuel Frederick Gray ....
, who described the species in 1865.
Description
The overall body shape of the strap-toothed 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 centimetres (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. BarnacleBarnacle
A barnacle is a type of arthropod belonging to infraclass Cirripedia in the subphylum Crustacea, and is hence related to crabs and lobsters. Barnacles are exclusively marine, and tend to live in shallow and tidal waters, typically in erosive settings. They are sessile suspension feeders, and have...
s quite frequently are found on the teeth, as well. Why the species would grow teeth that severely cut back on the size of prey it can consume is quite uncertain. The melon 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 metres (19 feet 6 inches), whereas females reach 6.2 metres (20 feet) and likely weigh around 1000-1300 kilograms (2200-2900 pounds), indicating they are probably the largest species in the genus. Newborn calves may be up to 2.8 metres (9 feet) in length.
Population and distribution
The Strap-toothed whale is distributed in cool temperate waters of the Southern HemisphereSouthern Hemisphere
The Southern Hemisphere is the part of Earth that lies south of the equator. The word hemisphere literally means 'half ball' or "half sphere"...
between 30° S and the Antarctic Convergence
Antarctic Convergence
The Antarctic Convergence is a curve continuously encircling Antarctica where cold, northward-flowing Antarctic waters meet the relatively warmer waters of the subantarctic. Antarctic waters predominantly sink beneath subantarctic waters, while associated zones of mixing and upwelling create a zone...
. It may occur south of 38° S year-round moving north of 38° S seasonally. As of 1991, there are about 140 records (nearly all strandings) of this species from New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
(50, including one sighting), Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
(over 40), southern Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
(about 40), southern Argentina
Argentina
Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...
and Tierra del Fuego
Tierra del Fuego
Tierra del Fuego is an archipelago off the southernmost tip of the South American mainland, across the Strait of Magellan. The archipelago consists of a main island Isla Grande de Tierra del Fuego divided between Chile and Argentina with an area of , and a group of smaller islands including Cape...
(10), southern Chile
Chile
Chile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...
(4), Falkland Islands
Falkland Islands
The Falkland Islands are an archipelago in the South Atlantic Ocean, located about from the coast of mainland South America. The archipelago consists of East Falkland, West Falkland and 776 lesser islands. The capital, Stanley, is on East Falkland...
(3), and Uruguay
Uruguay
Uruguay ,officially the Oriental Republic of Uruguay,sometimes the Eastern Republic of Uruguay; ) is a country in the southeastern part of South America. It is home to some 3.5 million people, of whom 1.8 million live in the capital Montevideo and its metropolitan area...
(1). Strandings have also been reported from Heard Island, the Kerguelen Islands
Kerguelen Islands
The Kerguelen Islands , also known as the Desolation Islands, are a group of islands in the southern Indian Ocean constituting the emerged part of the otherwise submerged Kerguelen Plateau. The islands, along with Adélie Land, the Crozet Islands and the Amsterdam and Saint Paul Islands are part of...
, and Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...
. More recently one individual was seen breaching between the South Orkney Islands
South Orkney Islands
The South Orkney Islands are a group of islands in the Southern Ocean, about north-east of the tip of the Antarctic Peninsula. They have a total area of about ....
and South Georgia
South Georgia and the South Sandwich Islands
South Georgia and the South Sandwich Islands is a British overseas territory and overseas territory of the European Union in the southern Atlantic Ocean. It is a remote and inhospitable collection of islands, consisting of South Georgia and a chain of smaller islands, known as the South Sandwich...
.