鲸目（Cetacea）,源自拉丁文 cetus（"鲸、鼠海豚、海豚"）,意指该亚目所有成员都是鲸、鼠海豚或海豚.

Cetacea, from Latin cetus (“whale, porpoise, dolphin”), in reference to the fact that all the members of this infraorder are whales, porpoises or dolphins.

種的俗名 Common names of members

鯨魚,鼠海豚,海豚.

Whales, porpoises and dolphins.

分佈 Distribution 

所有大洋.

All oceans.

體型 Size

大型动物,体型范围：体重 20-180 000 公斤,体长 1.2-30 米.

Large animals, size range: 20–180,000kg in weight  and  1.2–30 m in length.

形態描述 Morphology

牠们的前肢是鳍,身体呈流线型.几乎所有的鱼背上都有背鳍,但具体种类决定了背鳍的外观.背鳍和鳍的作用是在水中转向和稳定.鲸脂是一层厚厚的脂肪,包裹着身体.这使得鲸目动物的身体光滑、流线型,并起到隔热作用.大型鲸类的脂肪厚达半米.

Their forelimbs are flippers, and their body is streamlined. Nearly all of them have a dorsal fin on their backs, though the specific species will determine how this looks. The purpose of the fin and flipper is to steer and stabilize in the water. Blubber, a thick coating of fat, envelops the body. This gives cetaceans their sleek, streamlined bodies and acts as heat insulation. It can get as thick as half a meter in larger species.

生態與棲息地 Ecology & Habitat

大部分在海洋中,少数在淡水河中.

Mostly marine, few in freshwater rivers.

食性 Diet

纯肉食性（磷虾和浮游生物或鱼、软体动物、海豹等）.

Exclusively carnivorous (krill and plankton or fish, mollusks, seals, etc).

繁殖 Reproduction 

大多数鲸目动物每年只有一个交配季节,而且是一雌多雄交配.多只雄性鲸鱼聚集在一只雌性鲸鱼周围,争夺交配位置.雌鲸可能与多只雄鲸交配.每只雌鲸的幼鲸数量：1. 生育间隔：1-6 年.妊娠期：10 - 17 个月： 10 - 17 个月.雌性鲸目动物哺育幼崽约 6 个月至 2 年以上,雄性鲸目动物很少照顾幼崽.

Most cetacean species have one mating season per year and they are polygynous. Multiple males congregate around a single female and jostle for position to mate. The female may mate with several males. The number of young per female: 1. Interbirth intervals:1-6 years. The gestation period: 10 - 17 months. Female cetaceans nurse their calves about 6 months to over 2 years, male parental care is rare

已知的物種

Total species known

80

博物館收藏的物種

Species in the collection

3

在香港已知的物種

Species in Hong Kong

1

References

Wurtz, M., Repetto, N. (1999). Whales and Dolphins: A Guide to the Biology and Behavior of Cetaceans. Thunder Bay Press.

Berta, A., Sumich, J. L., Kovacs, K. M. (2005). Marine Mammals: Evolutionary Biology. Academic Press.