Odobenidae, from Greek ὀδούς (odoús, “tusk, tooth”) and Greek βαίνω (baínō, “to walk, go on foot”), means “tooth walker”, in reference to the fact that all the members of this family use their tusks to pull themselves out of the water.

Common names of members

Walruses.

Distribution  

Northern seas, near the Arctic Circle.

Size

Most weigh between 800 and 1,700 kg, with length typically ranging from 2.2 to 3.6 m.

Morphology

They have a large, heavy body with a lot of fat tissue. They have a round head with no external ear. They have a broad snot with many thick beards. They have streamlined fusiform bodies, tapered at both ends. They can turn their rear flippers forward and move on all fours. Both males and females have two long and large tusks (canines) for fighting and protection.

Habitat & Ecology

Ocean, ice floes, breaches.

Diet

They have a diverse and opportunistic carnivorous diet, feeding on more than 60 genera of marine organisms, including shrimp, crabs, priapulids, spoon worms, tube worms, soft corals, tunicates, sea cucumbers, various mollusks (such as snails, octopuses, and squid), some types of slow-moving fish, and even parts of other pinnipeds.

Reproduction 

They mate in winter. During the mating period, they live in social groups. In spring and summer, females give birth to usually one young on ice floes. Mothers and the newborns form their own social group which usually includes 20-50 individuals. Mothers are very protective. The young walruses stay with their mothers for about 2 years.

Species known in Hong Kong

0.

Total species known

1

Species in the collection

1

Species in Hong Kong

0

Reference

Fay, F. H. (1985). Odobenus rosmarus. Mammalian Species, 238, 1–7, https://doi.org/10.2307/3503810.

Sheffield, G., Fay, F. H., Feder, H., Kelly, B. P. (2006). Laboratory digestion of prey and interpretation of walrus stomach contents. Marine Mammal Science, 17(2), 310-330.  https://doi.org/10.1111/j.1748-7692.2001.tb01273.x. 

Fay, F. H. (1982). Ecology and Biology of the Pacific Walrus, Odobenus rosmarus divergens Illiger. North American Fauna, 74(74), 1–279. https://doi.org/10.3996/nafa.74.0001.