海象科（Odobenidae）源于希腊文ὀδούς（odoús,"獠牙,牙齿"）和希腊文βαίνω（baínō,"行走,步行"）,意为 "牙齿行走者",指的是该科所有成员都用獠牙将自己拉出水面.

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.

種的俗名 Common names of members

海象

Walruses.

分佈 Distribution

北极圈附近的北部海域.

Northern seas, near the Arctic Circle.

體型 Size

大多数体重在 800 至 1 700 公斤之间,体长通常在 2.2 至 3.6 米之间.

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

形態描述 Morphology

牠们的身体又大又重,有很多脂肪组织.牠们的头圆圆的,没有外耳.牠们有宽大的鼻涕和许多浓密的胡须.牠们的身体呈流线型纺锤形,两端变细.牠们的后蹼可以向前翻转,四肢着地.雄性和雌性都有两颗又长又大的獠牙（犬齿）,用于战斗和保护自己.

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.

生態與棲息地 Habitat & Ecology

海洋、浮冰、裂口.

Ocean, ice floes, breaches.

食性 Diet

牠们的肉食性的機會主義者,進食种类繁多,以 60 多个属的海洋生物为食,包括虾、蟹、栉水母、匙虫、管虫、软珊瑚、鳞栉水母、海参、各种软体动物（如蜗牛、章鱼和乌贼）、某些类型的慢速鱼类,甚至是其牠鳍足类动物的部分器官.

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.

繁殖 Reproduction 

牠们在冬季交配.交配期间,牠们过着群居生活.在春季和夏季,雌性通常会在浮冰上产下一只幼崽.母亲和新生儿组成自己的社会群体,通常包括 20-50 个个体.母海象非常注重保护.小海象与母亲在一起的时间约为 2 年.

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.

已知的物種

Total species known

1

博物館收藏的物種

Species in the collection

1

在香港已知的物種

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.