- Its taxonomy is still under debate; two other species have been proposed: I. boliviensis and I. araguaiaensis.
- Body colour varies with age: from grey to pink.
- Males are larger and heavier than females and tend to be more intensely coloured (pink).
- Its body length at birth is about 80 cm.
- Its body is extremely flexible, allowing it to navigate inside the flooded forest in search of its prey.
- It can move the head in all directions (up and down and sideways), which increases the area of scanning with the sonar.
- Inia is the only dolphin with two types of teeth (heterodonty).
- Its diet includes a great variety of fish (over 45 species).
- It is known to carry objects like sticks or branches, potentially as a sociosexual behaviour.
- It has been illegally hunted to be used as bait for piracatinga (Calophysus macropterus), which is attracted to rotting carcasses.
Amazon river dolphin