By Dr. Barbara Lundrigan and Allison Myers
Geographic Range
These whales have a worldwide distribution in deep waters below the 10 degree isotherm (Minasian et al. 1984, Watson 1981).
Biogeographic Regions:
indian ocean (native
); atlantic ocean
(native
); pacific ocean
(native
).
Habitat
-Z. cavirostris- have a worldwide distribution, though they seldom go north of the 10 degree isotherm. They are deep divers and prefer waters beyond the 1000 meter line (Watson 1981).
Physical Description
(6600 lbs)
-Ziphius cavirostris- is a medium-sized whale with an average body length of 6.4 meters. The female is usually a little larger and can be up to 7 meters long. Calves are 2.1 meters at birth. -Z. cavirostris- has a spindle shaped body that is a little stouter than other ziphiids. They have a small head (about 10% of their body length) and a distinct neck. As with all ziphiids, they have two grooves along the throat. They have a stubby beak which is almost indistinct in larger animals and a scooped out hollow behind the blowhole. Adult males have two large teeth on the lower jaw that grow up to 8 centimeters. In the females, the teeth never break through the gums. Some individuals have been found with 15-40 vestigial teeth that never erupted. -Z. cavirostris- have small rounded flippers that fold into depressions or "flipper pockets" on their flanks. They have a relatively tall fin (40 centimeters) that is shaped like a shark fin. There is a small notch in the center of their broad flukes.
The coloration of -Z. cavirostris- varies among individuals. In the Indopacific waters, the whales are often sienna colored, ranging from a dark yellow to a deep brown. Their backs are usually darker than their bellies, but some have a reversed coloration: pale backs with black stomachs. The head is almost always totally white, especially in older males. In the Atlantic waters, -Z. cavirostris- have a grey blue color, often with the same pale head coloration. They have dark spots around the eye. Juveniles are usually lighter than adults (Minasian et al. 1984, Watson 1981).
Some key physical features:
endothermic
; bilateral symmetry
.
Reproduction
The whales breed year round
Both sexes mature at about 5 meters long. There is thought to be a sex ratio of 67% males to 33% females. Little is known about the reproduction of this species because there does not seem to be a specific breeding season. The whales breed and calves are born all year round. The average lifespan is at least 35 years (
http://www.ims.usm.edu/~musweb/ziphcav.htm. Minasian et al. 1984, Watson 1981).
Key reproductive features:
iteroparous
; year-round breeding
; gonochoric/gonochoristic/dioecious (sexes separate); sexual
; viviparous
.
Behavior
Solitary males are occasionally seen, but usually Ziphius cavirostris travel in pods of around 15 individuals. They may breach, but they are often shy of boats. Their rounded heads can be seen during their blow and they swim at the surface taking breaths for about 20 seconds before they dive. They are deep divers and plunge almost vertically down for 30 minutes or longer. They are often found beached. Some animals have been seen with white oval scars on their belly from lamprey and crustacean (Livoneca ravnaudi) parasites. Adult males often have teeth marks on their beaks and backs (Watson 1981).
Key behaviors:
natatorial
; motile
; social
.
Food Habits
Ziphius cavirostris eats mainly squid and deep water fish. They also eat crabs and starfish (Watson 1981).
Primary Diet:
carnivore
(molluscivore
).
Animal Foods:
fish; mollusks; aquatic crustaceans; echinoderms.
Economic Importance for Humans: Positive
About 20 individuals are taken by Japanese whalers each year. This is a relatively small number and they are not regularly hunted (Watson 1981).
Conservation Status
Though not enough whales are taken to be a threat to the species, deaths may also occur from entanglement in gilnets, float lines from lobster traps, and long lines (
http://www.ims.usm.edu/~musweb/ziphcav.htm).
For More Information
Find Ziphius cavirostris information at
Contributors
Dr. Barbara Lundrigan
(author), Michigan State University. Allison Myers (author), Michigan State University.

