Narrow-ridged finless porpoise
| Narrow-ridged finless porpoise | |
|---|---|
 |
|
| Narrow-ridged finless porpoise | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Artiodactyla |
| Infraorder: | Cetacea |
| Family: | Phocoenidae |
| Genus: | Neophocaena |
| Species: | N. asiaeorientalis |
| Binomial name | |
|
Neophocaena asiaeorientalis (G. Cuvier, 1829) |
|
 |
|
| Narrow-ridged finless porpoise range in red | |
The narrow-ridged finless porpoise, or Yangtze finless porpoise, is a newly accepted species, by the International Union for Conservation of Nature (IUCN), of porpoise endemic to the western Yangtze river in China. After the extinction of the Yangtze river dolphin and the rapid decreasing of population, the Chinese government has given this species the utmost conservation status of National First Grade Key Protected Wild Animal to ensure its survival. Global conservation agencies and charities, such as the World Wildlife Fund and IUCN, have been collaborating with the Chinese government to ensure the survival of the species.
The narrow-ridged finless porpoise is found exclusively in the western Yangtze river. It is the only known exclusively freshwater species of porpoise. However, due to development of the river, they are restricted to the main river channel and its two largest appended lakes, Poyang and Dongting Lake.
There are two species of finless porpoise, and both inhabit the coastal areas off mainland China (e.g. Chongming Island), the Penghu Islands, and coastal Vietnam, including Halong Bay. The Matsu Islands are thought to be their northern limit, and the local population in this area is physically smaller than the Indo-pacific finless porpoise. These two subspecies overlap in the Matsu region.
As the name suggests, the finless porpoise is the only porpoise to lack a true dorsal fin. Instead there is a low, narrow ridge covered in thick skin bearing several lines of tiny tubercles. In addition, the forehead is unusually steep compared with those of other porpoises. They have fifteen to twenty-one teeth in each jaw, and, on average, fewer teeth than other porpoises, although there is some overlap, and this is a not a reliable means of distinguishing them.
...
Wikipedia