The Amazon River Dolphin, or Inia as they are referred to, differs from other species of dolphins in various ways. Traits such as movement, social structures, feeding, and appearance makes the Inia a very unique dolphin.
The Inia move much slower than other species of dolphins. They do not have powerful tail fins to speed them through waters. Also, Inia do not have a distinct dorsal fin; theirs is almost absent. The snout of the Inia is approximately a foot in length, and houses from 100 to 200 teeth, depending upon age. Another unique characteristic of the Inia is the presence of unfused vertebrae in its neck. This trait allows the Inia to turn its head 180 degrees to either side, giving them greater flexibility in catching prey in flooded forest floors, shallow waters, and tributaries.
Where most dolphin species have similar coloring, the Inia's coloration can range from white, to pink to gray. Not much is known of why the colors of adult Inia varies, but it is suspected that age, location of capillaries near the skin, water temperature, and chemical disposition of the water, especially iron content, play a big part.
When someone thinks of dolphins, they may picture a family pod swimming in a big blue ocean. Not so, with the Inia. The Inia are mainly solitary animals. There are very few sightings of these dolphins in a group. Other than for mating and mass feeding, these dolphins live and thrive alone. Mother and calf will stay together until the young one is strong enough to venture out on its own. This is thought to be the result of the Inia's absence of natural predators. It's only enemy, is man.
The destruction of the rain forest of the Amazon has directly affected the life span of the Inia. The construction of large hydroelectric dams along the rivers where the Inia live, and the deconstruction of the forests, has decreased their feeding, and breeding grounds by 45% over the last 15 years. Fishing nets along the rivers by local fishermen play a part in the endangerment of the Inia, as well.
There is only one Inia in North America. A male Inia resides at the Pittsburgh zoo and holds the longevity record for Inia that have lived in North America. More information regarding the "North American" Inia, and others, is available by visiting the Pittsburgh Zoo site at http://zoo.pgh.pa.us/wildlife/amazon_dol...
 |
 |
 |
Go To Page: 1 2
