The amazon river dolphin belongs to the family commonly known as Cetacea which also includes whales and porpoises.
This dolphin is one of several species of river dolphin.
The others include (may not include all species):
- The chinese river dolphin
- The Ganges river dolphin
- The Indus river dolphin
- The franciscana (la plata) dolphin
All dolphins with the exception of the franciscana dolphin (la plata dolphin) live in fresh water rivers.
The franciscana dolphin lives in or near the coastal shores in saltwater.
River dolphins can vary widely in terms of color.
The most common colors found are white, yellow, pink, brown, gray and black.
They have small eyes and are believed to have poor eyesight (compared to other dolphin species) due to the fact that they have evolved in shallow, dark, murky waters where eyesight plays less of a role.
These dolphins can grow to be over 8 ft. in length, but are typically smaller in size.
In terms of weight some dolphins can grow to weigh as much as 450 pounds or more, however as with weight these dolphins are generally lighter, weighing between 180 – 220 lbs. on average.
Because their vertebrae isn’t fused or connected the way other mammals are these dolphins can turn their head a full 180 degrees allowing them to fully view their surroundings.
In addition to their flexible necks they also have a long beak (size varies among species) which allows them burrow their mouth into logs and narrow spaces where they can catch their prey.
These dolphins survive on a diet consisting of small fish, crustaceans, shrimp and crab.
They are often seen swimming at or near the bottom of the river hunting for crustaceans.
Catfish and piranha are also considered a regular part of their diet and in some cases they may be observed hunting small turtles.
They can also be found inhibiting the rivers of Brazil, Columbia, Ecuador and Peru.
During the rain season when the river’s flood with water these dolphins travel through the marshes and forests in search of food.
These dolphins can be observed inhibiting several thousand square miles during these floods.
When the water levels lower they return back to the rivers and river banks.
Unfortunately not much is known about the social structure of the various river dolphins.
These dolphins are known to communicate using a well structured variety of high and low range click and whistles.
Depending on the species of river dolphin the length, frequency and range of their clicks and whistles can vary quite a bit.
These sounds are often used during times of hunting (echolocation) or when they want to communicate a need or desire.
The average gestation period (the period from conception to birth) for amazon river dolphins is about 9 months.
Most births occur during the summer time between July – September.
These dolphins tend to be very closely connected to their family, at least in their early youth.
Newborns can usually be seen swimming along with two or more adults for the first several months after birth.
During mating season the female dolphins can be found traveling deep into the forests (possibly to avoid the highly competitive male dolphins).
The males have been known to attack one another during these periods when in search of a mate and may end up fighting one another over a female dolphin.
Due to the fact that these dolphins live in shallow river waters their main threats are humans.
Pollution, boats and accidental fishing hazards all contribute to the endangerment of these dolphins.
Unfortunately some species have become highly endangered and may become extinct in the near future.