Extreme Amazon

Common Iguana

The Extreme Amazon gallery is home to many animals with incredible adaptations. The 3,800-gallon freshwater tank in our Extreme Amazon gallery highlights the way some Amazonian fish have adapted to life in the world's largest river. If you pay attention, you will notice fish swimming at the bottom of the tank have mouths that face downward, while fish swimming near the top have mouths that open toward the surface. Specialized jaw structures enable the fish to catch and eat whatever food is available in their habitat, so fish with mouths on the bottom can obtain food from the mud while fish with mouths that open upward are able to catch food at the surface. Extreme Amazon also features freshwater stingrays, a reptilian couple, and a pop-up tunnel that gives kids a close-up view of the animals. 

Extreme Amazon Animals 

The Amazon rainforest and Amazon River Basin are significant to humans. It is the largest rainforest globally and is often referred to as the “lungs of the planet” because it produces about a quarter of all Earth’s oxygen. Additionally, it provides about 80% of the food consumed by the developed world. As the largest by volume and second-longest river globally, the Amazon River is one of the most biodiverse regions globally, meaning it has a wide variety of different plants and animals. Home to more than 2,000 other fish species, the Amazon River has more fish species than the entire Atlantic Ocean!  

Ray-Finned Fish (Actinopterygii)

Most of the fish in our Extreme Amazon exhibit belong to the largest group of bony fish known as actinopterygians or ray-finned fishes. Ray-finned fish account for half of all living vertebrates (animals with a backbone). They get the name “ray-finned” from the arrangement of the bones in their fins; all ray-finned fishes have paired fins with a fan-like bone structure. They also have a swim bladder, a sac of air, like a lung, that helps them control buoyancy in the water. 

One of the largest groups of ray-finned fish is catfish, with more than 1,000 different species of catfish found in the Amazon River.   

Freshwater Rays

Just like their marine counterparts, orange-spotted freshwater stingrays are cartilaginous fish; instead of skeletons made up of bone, they are made up of cartilage. Freshwater stingrays share many of their characteristics with saltwater rays: they have gills on top of their heads, mouths on the bottom, and a venomous stinger along their tail. 


Lurking above in the trees you will also notice one male and one female green iguana. Averaging six feet in length and weighing 11 pounds, green iguanas are some of the largest lizards found in the Americas. Iguanas communicate by bobbing their heads. In parts of the world, iguanas are called "pollo de arbol," or chicken of the trees, because they are often on the menu!   

Fun Facts

  • The ripsaw catfish has the most armor of any catfish. It has thickly armored, razor-like scales along its sides, and each scale has hooks along the edge.  
  • The silver arowana is a mouthbrooder, which means it protects its eggs by holding them in their mouth until they hatch.  
  • The pacu has specialized square, human-like teeth that enable it to eat fruits, nuts, and seeds that fall into the water. However, their herbivory does not limit their size—they can weigh up to 55 lbs! Pacus are important for seed dispersal in the Amazon.
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