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Critters of the Amazon River

On the December Enrichment Voyage: Passage through the Amazon, participants will have the opportunity to sail up the Amazon River. The Amazon River is one of the longest rivers in the world, second only to the Nile, and is responsible for about 20 percent of freshwater discharge into the oceans. The Amazon Rainforest is the drainage basin for the Amazon River and is home to the world’s highest biodiversity level. Over one-third of the world’s species can be found in the Amazon Rainforest. Below are a few species unique to the river and rainforest.

Amazon River Dolphin (Inia Geoffrensis)

Amazon river dolphins on enrichment voyage
Amazon River Dolphins

The Amazon River Dolphin, also known as boto or bufeo, is the largest species of freshwater dolphin. Averaging about 6.5 feet in length, it varies in color from shades of bright pink to dull, gray pink. The rays of the sun cause these dolphins to lose their color, so the murky tint of the Amazon River helps it maintain its illustrious hue. The Amazon river dolphin feeds on over 50 different types of fish. One characteristic unique to this dolphin is its neck, which lacks a fused vertebra, allowing for 180-degree rotation.


Giant Amazon River Turtle (Podeocnemis expansa)

Giant Amazon River turtles on semester at sea enrichment voyage
Giant Amazon River Turtles

The Giant Amazon River Turtle is one of the largest freshwater turtles in the world. Compared to other sea turtles, it is a powerful swimmer. Feeding on primarily fallen fruits and seeds, its diet also includes freshwater sponges and insects. An adult female giant Amazon River turtle can weigh up to 200 pounds and is so large that she has few natural predators. Hatchlings, by comparison, are much more susceptible to predators like black vultures. Jaguars and black caimans are the only animals that are large enough to eat a giant Amazon River turtle.



piranha on semester at sea enrichment voayge on Amazon River





Piranha (Pygocentrus nattereri)
The piranha is known in Western culture as one of the most feared creatures of the water. Nonetheless, natives of the Amazon forest regularly swim in piranha-infested waters. Piranhas are very small fish with large teeth that are usually a grey or blue color. Although they are omnivores, they hunt in groups called shoals. One characteristic unique to the piranha is that when a tooth is lost or broken, a new one will grow in its place.

Dwarf Caiman (Paleosuchus palepebrosus)

Dwarf Caiman on the Amazon River during Semester at sea enrichment voyage
Dwarf Caiman

The Dwarf Caiman is about one to one-and-a-half meters long and is brown in color. The head of the caiman has a distinct appearance as it is short and smooth with the upper jaw overlapping the lower. To assist in hunting prey, the caiman looks like a log floating in the water rather than like an animal. Because of the structure of its teeth, the caiman often feeds on invertebrates. Interestingly, the sex of caiman offspring is determined by the incubation temperature of the nest. Lower incubation temperatures usually produce females while higher temperatures produce males.

These four animals are just a taste of what participants might see on their journey through the Amazon. The Field Program will include Amazonian adventures such as kayaking, river tubing, snorkeling, and hiking. Click here for a sample of the December field offerings.





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