The X-ray Fish
The X-ray fish is a small freshwater fish of South America. It is also called the X-ray tetra. The X-ray fish is unusual because light can pass through most of its body. As a result, you can see through the X-ray fish.

The X-ray fish has bands of yellow, black, and white on most of its fins. It has a reddish tail fin. It often has a black spot behind the eye. Adults grow to less than 2 inches (4.5 centimeters) in length.
The X-ray fish is found widely in the Amazon and Orinoco river basins of South America. It feeds on water insects and other small animals.
X-ray fish are popular in aquariums. They may live for up to five years.