porpoise
Also known as mereswine, Phocoenidae
Porpoises () are small dolphin-like cetaceans classified under the family Phocoenidae. Although similar in appearance to dolphins, they are more closely related to narwhals and belugas. There are eight extant species of porpoise, all among the smallest of the toothed whales. Porpoises are distinguished from dolphins by their flattened, spade-shaped teeth distinct from the conical teeth of dolphins, and lack of a pronounced beak, although some dolphins (e.g. Hector's dolphin) also lack a pronounced beak. Porpoises, and other cetaceans, belong to the clade Cetartiodactyla with even-toed ungulate
AI overview
Porpoises are small toothed whales that look similar to dolphins but are actually more closely related to narwhals and belugas, and can be distinguished from dolphins by their flat, spade-shaped teeth and lack of a pronounced beak. There are eight species of porpoises alive today, making them among the smallest of all toothed whales.
AI-generated from the Wikipedia summary — may contain errors.
Species
porpoises
Family
- PhylumChordata
- ClassMammalia
- OrderCetartiodactyla
- FamilyPhocoenidae
Habitatmarine, brackish, freshwater
Observations10,062
属 鼠海豚属 Phocoena 无喙鼠海豚属 Phocoenoides 江豚属 Neophocaena 鼠海豚（學名Phocoenidae），鯨目的一科，體型非常像海豚，但吻部不尖，又像鲸，共分爲三個屬： 鼠海豚属 Phocoena 鼠海豚 P. phocoena 南美鼠海豚 P. dioptrica 棘鳍鼠海豚 P. spinipinnis 太平洋鼠海豚 P. sinus 无喙鼠海豚属 Phocoenoides 无喙鼠海豚 P. dalli 江豚属 Neophocaena 江豚 N. phocaenoides 窄脊江豚 N. asiaeorientalis 長江江豚 N. asiaeorientalis ssp. asiaeorientalis 取自“https://zh.wikipedia.org/w/index.php?title=鼠海豚科&oldid=42667475” 分类：鼠海豚科 隐藏分类：本地相关图片与维基数据不同
via
Research
1,565 papersArticle
20 sectionsContents
- Taxonomy and evolution
- Biology
- Anatomy
- Locomotion
- Senses
- Sleep
- Behaviour
- Life cycle
- Diet
- Interactions with humans
- Research history
- In captivity
- Threats
- Hunting
- Fishing
- Environmental hazards
- Conservation
- See also
- References
- External links
Porpoises () are small dolphin-like cetaceans classified under the family Phocoenidae. Although similar in appearance to dolphins, they are more closely related to narwhals and belugas. There are eight extant species of porpoise, all among the smallest of the toothed whales. Porpoises are distinguished from dolphins by their flattened, spade-shaped teeth distinct from the conical teeth of dolphins, and lack of a pronounced beak, although some dolphins (e.g. Hector's dolphin) also lack a pronounced beak. Porpoises, and other cetaceans, belong to the clade Cetartiodactyla with even-toed ungulates.
Porpoises range in size from the vaquita, at in length and in weight, to the Dall's porpoise, at and . Several species exhibit sexual dimorphism in that the females are larger than males. They have streamlined bodies and two limbs that are modified into flippers. Porpoises use echolocation as their primary sensory system. Some species are well adapted for diving to great depths. As all cetaceans, they have a layer of fat, or blubber, under the skin to keep them warm in cold water.