By Colette Hendricks
Geographic Range
Hyperoodon planifrons is found in the waters off of Australia, New Zealand, Brazil, Argentina, Tierra del Fuego, the Falkland Islands, South Georgia, the South Orkney Islands, South Africa, and the Pacific and Indian ocean sectors of Antarctica. Southern bottlenose whales have also been sighted near Sri Lanka.
(Nowak 1997, Tinker 1988)
Biogeographic Regions:
indian ocean (native 
); pacific ocean (native ).
Habitat
Hyperoodon planifrons mainly stays in cooler waters and approaches the ice packs of Antarctica during the summer. For the winter months, southern bottlenose whales migrate towards tropic waters (Minasian et al. 1984).
Aquatic Biomes:
coastal .
Physical Description
Hyperoodon planifrons individuals grow to about 8 meters in length. Sexual dimorphism is seen in this species, with the males averaging a length of 7.5 meters and the females averaging only 6.5 meters. Body mass has been estimated at 6 to 8 tons. The body of H. planifrons is cylindrical in shape and tapers toward the tail in the last 1/3 of its length. The tail flukes are wide and lack the notched center that is often seen in other cetaceans. Southern bottlenose whales have short, distinct beaks protruding from an inflated forehead or melon. In females and young males, the forehead slopes smoothly into the beak. In older males, the forehead rises abruptly from the beak. The dorsal fin of H.planifrons is located 2/3 of the body length from the head, measures between 30 to 40 cm, and is sickle-shaped with a blunt tip. This whale's flippers are small, short, and also blunt-tipped.
Male H. planifrons have one pair of short, conical teeth which are situated at the tip of the lower jaw. Teeth are not found in the upper jaw. The teeth of females are either smaller or do not emerge at all. Rows of vestigial teeth are often present in the lower and upper jaw.
Southern bottlenose whales are a brownish-grey color on the head, back, dorsal fin, flippers, and tail . This color is paler on the belly, throat, and sides. However, coloration becomes lighter with age. Calves are a grayish-brown to black color, while older whales are completely yellowish-white in color.
(Tinker 1988, Nowak 1997, Baker 1983, Minasian et al. 1984)
Some key physical features:
endothermic ; bilateral symmetry .
Reproduction
Calving in Hyperoodon planifrons occurs in the spring or summer. The young measure about 3 meters at birth. Very little information is known about the reproductive cycle of H. planifrons, but it probably resembles the cycle of its close relative, Hyperoodon ampullatus, northern bottlenose whales. In that species, females probably give birth every 2 years, with a gestation period of 12 months. Weaning of young takes place after one year. Sexual maturity of female bottlenose whales is reached between the ages of 8-12, and in males, between 7-11 years of age. The life span of H. planifrons is at least 37 years.
(Tinker 1988, Nowak 1997)
Key reproductive features:
iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous .
Behavior
Southern bottlenose whales generally stay well out to sea and are found in waters over 1,000 meters deep. Herds of H. planifrons are small, ranging from 2 to 12. Hyperoodon planifrons travel and dive together as a very compact group, and dives may last up to 45 minutes. A frequent behavior of H. planifrons is diving under ice and raising the beak clear of the water on the last surfacing before sounding. Interactions or contact with other species is uncommon for H. planifrons. Little information is available about their mode of communication, but it is probably quite similar to H. ampullatus. A variety of sounds have been recorded for that species, which include a series of clicks and whistles used for echolocation and communication, respectively.
(Nowak 1997, Minasian et al. 1984, Ponganis and Kooyman 1995)
Key behaviors:
natatorial ; motile ; social .
Food Habits
Hyperoodon planifrons is known to feed primarily on squid, and most likely, on fishes (Tinker 1988).
Primary Diet:
carnivore (molluscivore ).
Animal Foods:
fish; mollusks.
Economic Importance for Humans: Negative
There are no adverse effects of H. planifrons.
Economic Importance for Humans: Positive
There is very little economic importance attached to this species. Hyperoodon planifrons has never been subjected to systematic whaling, unlike its close relative, Hyperoodon ampullatus.
(Tinker 1988, Minasian et al. 1984)
Conservation Status
IUCN lists Hyperoodon planifrons as conservation dependent. This designation means that this species would fall into a higher category of threat or be driven to the point of extinction, if it were not for conservation efforts (Baillie and Groombridge 1996).
Other Comments
Hyperoodon planifrons may also be called the Antarctic bottlenose whale.
Ziphiids have a pair of grooves on their throat that converge anteriorly to form a V pattern at the chin.
A large bottlenose whale can yield up to 200 kg of spermati oil, which is used in making ointments and fine, smokeless candles. Furthermore, it can yield up to 2,000 kg of blubber oil, which is a base of many skin creams and cosmetics.
Based on geological evidence, Hyperoodon ampullatus and Hyperoodon planifrons probably diverged as recently as 15,000 years ago. There are fossil records of ziphiid whales from the lower Miocene Epoch to the Holocene Epoch.
(Mead 1989, Tinker 1988, Nowak, 1997)
For More Information
Find Hyperoodon planifrons information at
Contributors
Colette Hendricks (author), University of Michigan.
