The Hooded Seal (Cystophora cristata) is an arctic pinniped found only in the central and western North Atlantic ranging from Svalbard in the east to the Gulf of St. Lawrence in the west.

Naming

The generic name means 'bladder-bearer' in Greek, from the peculiar inflatable appendage on the nose of the adult male. The seal is named after a cap-like bulge essay on the forehead and nose of the adult male which does not hang down, unlike that of the elephant seals.

The bulge

The bulge develops when the seal is four years old. The male can blow up this bulge, so that the size of its head seems to be twice as large. Very rarely the bulge can become infected and turn a bright red color.

Size

Adult males are long on average, and weigh . Sexual dimorphism is obvious from birth and females are much smaller: long and rarely weighing . The colour is silvery; the body is scattered with dark, irregular marks. The head is darker than the rest of the body, and without marks.

Lifestyle

In April through June, after the breeding season, this species travels long distances to feed and eventually gather together again in separate moulting areas on the ice from June through August. After moulting, it disperses widely again to feed in the late summer and autumn before returning to the breeding areas in late winter.

Breeding

There are four major breeding areas: the Gulf of St. Lawrence, the "Front" east of Newfoundland, Davis Strait (between Greenland and northern Canada) and the West Ice near Jan Mayen.

Offspring

Pups are about long at birth and weigh about . They are born on the ice from mid-March to early April with a well-developed blubber layer and having shed their pre-natal coat. They are born with a slate blue-grey coat (giving them the name "blueback"), with a pale cream color on the belly, which they will moult after about 14 months. Nursing of the pup lasts for an average of only 4 days, the shortest lactation period of any mammal, during which the pup doubles in size from about. This is possible because the milk that they drink has a fat content of 60%. The female pup will mature between ages 3 and 6, whereas the male pup will mature between ages 5 and 7.

Lifespan

The Hooded Seal can live to about age 30 to 35.

References

External links

• SCS: Hooded Seal
• CRESLI hooded seal