The x-ray tetra is naturally from the Amazons rivers coastal waters which is found in South America. They are now one of the most popular freshwater fish to be kept in an aquarium. They were discovered in 1894 by Ulrey. The X-ray tetra is translucent with a tinge of gold in some places giving it’s nickname the water goldfinch a meaning. But if you looked closely enough at the X-ray tetra you can see it’s backbone because of it’s translucent skin. They have a yellow and black dorsal fin. This fish is quite adaptable aswell and would quite easily fit in at your aquarium at home as long as there is no predators.