The Amazon River Dolphin
Inia Geoffrensis
Classification Order
Phylum: Chordata
Class: Mammalia
Order: Cetacea
Family: Iniidae
Genus: Inia
Species: Inia Geoffrensis
(most closely related to the long finned and short finned pilot whales)
There are four other types of river dolphin: Indus, Ganges, Baiji, and Indian.
What and How the River Dolphin Eats
*echolocation: location of objects as reflected by a sound emitted by animals which are able, such as dolphins or bats.
*average body weight: in females the average weight is 154 kg, and in males the average weight is 100 kg.
Physical Features & Movement
Color: pale pink or grey
Flexible neck, unlike other dolphins
Longer rostrum than other species of dolphins (both freshwater & saltwater)
Unlike other dolphins, they do not have dorsal fins; instead they have a dorsal ridge.
Moves by shifting tail vertically
Max. speed in water: 18 mphSize:
- 2 - 3 meters in length (72 - 98 inches or 6 - 8 feet)
Weight: 220 - 440 lbs
Life span: 12 - 18 years
Poor vision; relies on echolocation to maneuver in the water and to locate meals, prey, and predators.
Skeleton
River Dolphin Full Body
River Dolphin Embryo
Behavior & Social Life
River dolphins reproduce in a period of time that extends from the end of October to the beginning of November, and are pregnant from nine to twelve months.
Families become very attached to each other in these pods.
Social politics are visible in these large groups, but this order is not determined by violent acts. Violence, as it is observed in captivity, mainly occurs when there is a situation resulting the showing of the dolphins' more protective side for a mate or injured family member.
They are active at both day and night and have been observed in somewhat of an alliance with the gray river (tucuxi) dolphin and giant otters while in pursuit of their next meal. In the wild, they are curious animals, however difficult to train in captivity and more reserved than other species of dolphin.
The amazon river dolphin is sedentary and does not move themselves, or their pod, very far throughout 1-2 years unless necessity is shown at any time other than during migration season, which are small lapses of time that occur throughout the year. Territory battles are not regular, so home ranges are assumed to be large and to overlap each other throughout the lake.
To attract a mate, male river dolphins will wave a tree branch above the surface or strike rocks or chunks of clay against the river bottom, both while making noise.
*Mating: river dolphins do not mate for life, only for a season, however sometimes will travel with their families in a pod.
Suggested Reading
Habitat and Environment
In Literature:
*Traditional Amazonian myths make the river dolphin out to be an animal that can morph into a handsome human wearing a hat (for the purpose of hiding its blowhole), seduce and impregnate young women, and then return to the water as a river dolphin again. They are also said to capture some of the women or children and take them back to the other encantados. Eye sight with one is supposed to curse a human with nightmares for the rest of their lives.
Conservation
Dam-building, fishing net entanglement, boat traffic, and pollution contribute to the constant decline in population.
Cites:
http://wwf.panda.org/who_we_are/wwf_offices/pakistan/indus/indus_facts/
http://animaldiversity.ummz.umich.edu/accounts/Inia_geoffrensis/
http://animaldiversity.ummz.umich.edu/accounts/Inia_geoffrensis/#behavior
http://www.isptr-pard.org/dolphin.html
http://animaldiversity.ummz.umich.edu/accounts/Inia_geoffrensis/#behavior
http://www.isptr-pard.org/dolphin.html
http://rio.wikia.com/wiki/Amazon_River_Dolphin
http://www.today.com/id/23812381/ns/today-today_tech/t/dolphin-bling-attracts-ladies/#.UzmcMhYZ7Bw
http://www.rainforest-alliance.org/kids/species-profiles/river-dolphin