River dolphins are some of the most
As opposed to oceanic
dolphins, they do
not live out in the open oceans but instead in freshwater inland
and coastal estuarine rivers. They are
the most endangered dolphins
because their habitat is restricted to
rivers that get polluted. They also get entangled in fishing nets, are
hunted and sometimes, have to compete with man for their food.
River dolphins also differ from oceanic
dolphins in their appearance. They have a longer snout- sometimes up to 2 feet long! They
are also less active, have smaller eyes and poor vision due to the fact
that they live in muddy water. They rely on heavily on their
echo-location to find
their way and to find their food.
dolphins can grow up to eight feet and can be all different
colors, including pink!
are only six
species in the world and one of
these is divided into two sub-species. Four of them live in fresh water
and one in
They all belong to different
within the superfamily Platanistoidea.
South Asian River Dolphins
The South Asians are
divided into two subspecies. Both are endangered and it has
been controversial whether they should be the same, or two different
The Araguaian livesonly in the Araguain River basin has been declared a new
species! Unfortunately, there are only 1000-5000, which puts them on
the endangered list.
Their appearance is much like the Boto and Bolivian River Dolphins with
a long snout, and a large rounded forehead. The color ranges from light
grey to pink with some individuals a bright pink!
Bolivian River Dolphin
Bolivian, locally known as "Buefos," lives in the
Madeira drainage above the Teotonia rapids in Bolivia. It is considered
to be a separate species because it is
isolated from the other Amazon Dolphins, it is a lighter color
and has more teeth.
La Plata Dolphin
leaves fresh water in the winter and moves to the coastal waters along
the south-eastern coast of South America. As
opposed to Boto, it is found in coastal rivers. This is the only
species that can handle estuarine water. The La
Plata Dolphin is small with gray skin and It is
also known in Uraguay as "Franciscana."
or Yangtze or Bajij, was found in Chang (Yangtze) River in eastern China. As of
December 2006, this dolphin was determined to be extinct. The causes
for their demise are over-fishing, damming, underwater sonar pollution,
other pollution of the water and hunting.