- Education and Science
Some Important Freshwater Inhabitants and Amphibians of The Amazon River
The Amazon's endless quite streams, lakes and warm equatorial and tropical climate make a heaven to the all Freshwater Inhabitants and Amphibians living in this basin. The greatest freshwater river basin of Amazon has more than 5000 different species of fishes and other amphibians. Let us see some of the important Freshwater Inhabitants and amphibians of the basin.
Turtles, Pink Dolphins, Alligators, Crocodiles, Anacondas, Piranhas and Frogs are some of them.
The weather conditions of Amazon basins are favorable for the Amhibians like Frogs, Anacondas and Pink Dolphins which could live in both land and water.
These are harmless reptiles reach a diversity anywhere else on the earth. The big headed Amazon River Turtle (Peltocephalus dumeriliana ) has a grey-brown to black domed upper shell ( carapace ) with a keel running down its centre which is pronounced in juveniles but becomes lower with age. Likewise, the carapace scutes of young adults are marked with growth rings ( annuli ) but those of older turtles often become worn smooth. The lower shell is yellow to brown and the neck and limbs are grey to olive. The large triangular head is also usually grey to olive but may become noticeably white adults. Jaws by contrast are tan coloured with upper jaw strongly hooked and the snout protruding. All toes are webbed.
These are omnivorous animals feed on fish, fruits, aquatic plants and algae. They grow upto the length of 44 cm.
The Pink Dolphins are the amazing animals of Amazon region. Of the five freshwater species of Dolphins in the world, the Pink Amazon River Dolphins (Iniagesffrensis) are considered to be the most intelligent. They are friendly sensitive mammals with a brain capacity of 40 % larger than that of human. But it has become one of the endangered species due to the accelerated and commercialized rape of Amazon basin. The Pink Dolphins engage in solitary hunting and feeding strategies during the high water season when their prey fishes disperse into the flood plains. At other times they found in small family groups of 5-8 animals which seem to be lead by a dominant adult male. They grow upto 10 feet long and weigh 90 kg. Usually calves can be born between the months of July and September and new born calves are in the length of 75 cm. A unique characteristic of these fishes is the unfused vertebrae in its neck, which allows for the 180 degree head turn. This enables them the easy hunting of their preys.
The Amazon Rivers are the home for the world most dangerous fishes called Piranhas. They grow upto 60 cm long. These fishes hunt in shoals or packs and can kill cattle or humans and strip the flesh from the bones in a few minutes. There are about 20 species of piranhas in the Amazon region. But all of them are not dangerous. Some of the fishes are having the habit of eating only insects, fruits,leaves and seeds. The most dangerous species are growing more than 40 cm long and black in colour. The fruit eating Piranhas are playing a vital ecological role by aiding the seed dispersal. The seeds from the fruits they eat are deposited with out any damage after passing through their digestive systems.
Alligators and Crocodiles
The Black Caiman (Melanosuchus niger ) is the largest Crocodilian found in the Amazon river. They grow upto 20 foot in length. The Alligators and Crocodiles can be differed only by their head and jaws. The Alligators are having wide and flat head with U shape whereas the Crocodiles are having sharp heads with exposing of lower teeth. Both Crocodiles and Alligators are the best swimmers and show only their eyes and nostrils above the water surface and wait patiently for their preys. They will also gently swim to get close enough to the prey and launch an immediate attack on the preys. Crocodiles and Alligators grabe their prey with their powerful jaws and pull it underwater to drown it to death.
The warm temperature and plenty of water and preys of the region are creating favorable living conditions to the both Crocodiles and Alligators. They feed on variety animals ranging from insects, frogs, fishes, turtles and birds.
The Peruvian scientists have discovered the fossilized remains of gaint 46 foot long Crocodile deep in the Amazon forests. It is believed that they might have found in Amazon region when the river was as an inland ocean million of years ago. The team estimates that creature once weighed nine tonnes and had 4 foot long head.
There are two Green and Yellow species of Anacondas found in the region. Of which Green Anaconda is bigger in size. They can grow upto 30 foot long and weigh 300 pounds. It spends a lot of time in slow moving water. It is an amphibian animal as it lives both in water and some times in land. When it is hungry it will uncoil itself and lie still in the water with only its eyes above the water surface waiting for the prey. The largely found capybara is the frequent prey of Anaconda. Besides the rodent animals they also eat deers, birds and other animals. After eating satisfactorily they rest for more than two weeks. Anacondas are viviparous and 20-100 little snakes are born at a time. It is rare for Anacondas to attack fishermen and human beings unless they are being directly agitated or disturbed. In their real life they are soft and they are not behaving as shown in the films.
The rainforest atmosphere is favorable for the growth of variety of frogs. There are more than 1000 species of frogs are found in the Amazon basin. Unlike other temperate frogs of the world which mostly habitat around water aea, the frogs here found abundant in all the trees of the forests. Though they are Amphibians, the frequent heavy rains of the forests facilitate them to move along the forest trees. The Huge Horned Frog is commonly found in the forests. The Amazon basin is the only region in the world where this specie of the frog is found. Among the best known of rainforest frogs are tiny but brilliantly colored poison dart frogs. These frogs are from the family Dendrobatidae and secrete powerful toxins from glands on their back to escape from their predators.