Development & Aid, Environment, Tierramerica

Smart Cetaceans

Mar 3 2002 (IPS) - Dolphins have been popular with humans since ancient times due to their astonishing ability to learn and their extraordinary behaviors. But while they are admired by young and old alike, they suffer the impacts of human activities and are not strangers to the threat of extinction.

There are 70 species listed in the suborder of cetaceans known as 'Odontoceti' in the classification of animals. More informally, these are “whales with teeth”, and cover all sea- and river-dwelling dolphins.

According to information found on the Internet, there are some 30 ocean dolphin species and five river dolphin species.

Dolphins are mammals, meaning mothers nurse their young, and are the result of a long process of evolution, which experts say began with creatures that lived on land. An important trait of this group of species is that, unlike fish, and like their cousins the whales, dolphins must breath air.

These excellent swimmers can reach speeds of 40 km per hour. They also possess a sophisticated sonar system that allows them to locate objects in the water around them.

But one of their most astonishing characteristics is the relatively large size of their brains, which determines intelligence. Dolphins are naturally curious and can easily learn behavior taught by humans.

The survival of dolphins, however, is at risk. Many fall victims to fishing nets, a problem that is the focus of several conservation campaigns worldwide. There is also a great deal of criticism about keeping these extremely intelligent animals in captivity and using them in marine shows or in experiments.