True's Beaked Whale
Mesoplodon mirus


Other Names: Wonderful Beaked Whale

Habitat: Offshore

Status: Unknown

Population: Unknown

Threats: Unknown

Group Size: Unknown

Fin Position: Far behind center

Newborns: c.7 ft (2.3 m), c.300 lbs (136 kg)

Adults: 16-17 ft (4.9-5.3 m), c.1-1.5 tons

Diet: Squid or octopus

Teeth: 0 on top row, 2 on bottom row


Description

Dorsal fin:

- small, curved dorsal fin
- concave trailing edge

Flukes:

- pointed tips
- flukes darker than rear third of body (southern hemisphere only)
- concave trailing edges
- no notch n middle, but some individuals may have slight nick
- narrow tail stock, with ridge along the top

Flippers:

- gray upper sides and undersides of flippers
- flippers low down on body
- flipper can be tucked away in "pocket" on underside
- small, narrow flipper

Head:

- dark patch around each eye
- medium-sized beak with white lower jaw
- slightly bulging forehead
- slight indentation at blowhole

Jawbone (male):

- small, forward-leaning teeth
- teeth located at extreme tip of lower jaw

Flipper Pockets:

- like other beaked whales in the genus Mesoplodon, True's Beaked Whale has a small depression on each side of its body, immediately behind the point where the flipper is joined to the chest area
- the animal is believed to tuck its flippers away in these depressions in the body wall while it is swimming
- the pockets are visible only when a stranded animal can be examined closely

Other characteristics:

- back and sides covered in scratches and scars
- dark gray or bluish gray back
- rear third of body white or light bluish gray
- mottled gray on underside, with brownish yellow tints
-
- medium gray upper side (northern hemisphere)
- pale grayish brown underside (northern hemisphere)


Behavior

- has never been positively identified at sea, so nothing is known about behavior
- lack of positive sightings may reflect identification difficulties at sea
- scratches an scars on back and sides indicate fighting between males
- likely to be a deep diver


Distribution

- temperate North Atlantic, southeastern Africa, and Australia
- believed to be found only in North Atlantic until a specimen was discovered along the Indian Ocean coast of South Africa in 1959
- several other southern hemisphere records since then, from South Africa, Australia, and an unconfirmed report from New Zealand
- These may represent geographically separate stocks or, alternatively, the range may be more widespread than the few records suggest
- most strandings from the western North Atlantic, but a few from the eastern side: mainly from the west coast of Ireland, but also Britain, France, and the Canary Islands
- may be associated with the Gulf Stream



TMMSN Galveston

TMMSN Corpus Christi

Return To Gulf of Mexico Species
Return To Cetaceans of the World

e-mail suggestions or questions to
tmmsn@sci.tamucc.edu

This page was created by:Candice Orca Mottet