River dolphins are five species of dolphin which live in fresh water rivers and estuaries. Three species live in fresh water rivers. The La Plata Dolphin lives in salt water estuaries and the ocean.
- South Asian river dolphins (two sub-species)
- South American river dolphins (three species)
- Chinese river dolphin (or Baiji), Lipotes vexillifer – Lives in the Yangtze River in China (one of the most endangered of all dolphins and whales). Recent counts have come up with 17 remaining individuals.[2] Scientists now want to raise some dolphins in a lake.
Differences between marine and river dolphins
Both river dolphins and marine dolphins belong to a group of mammals called cetaceans. The snout of a river dolphin measures about 58 centimeters (2 ft) long, approximately four times as long as that of most marine dolphins. They use their long snout to search for fish on the muddy bottom of the river. River dolphins have smaller eyes than marine dolphins, and their vision is poorly developed because they live in dark, muddy water. River dolphins are less active than marine dolphins because they do not need to search so widely to find fish. Marine dolphins work in pods (packs) because when they find a shoal of fish then they work together to make the most of their find. River dolphins work mostly as individuals or small groups.[3]
Taxonomy
The following is the taxonomy of river dolphins, or how dolphins are classified: [3]
River dolphin classification
- Superfamily Platanistoidea
- Family Platanistidae
- Family Iniidae
- Family Lipotidae
- Family Pontoporiidae
References
- ↑ McGrath, Matt 2014. Brazil dolphin is first new river species since 1918. BBC News Science & Technology.[1]
- ↑ [2]
- ↑ 3.0 3.1 Rice D.W. 1998. Marine mammals of the world: systematics and distribution. Society of Marine Mammalogy Special Publication #4, p231.
Other sources
River-Dolphins-and-their-habitat[permanent dead link]
