X-Ray Tetra

The X-Ray Tetra is a small species of schooling Fish that is naturally found in the Amazon River's coastal waters in South America. The X-Ray Tetra is also known as the Golden Pristella Tetra and the Water Goldfinch due to the faint golden colouration of their translucent skin. They were first described by Ulrey in 1894 and have since become one of the most popular freshwater Fish kept in artificial aquariums today. Although the X-Ray Tetra is the only known species in it's genus, it is closely related to other small and colourful South American Fish, including the nearly 100 other Tetra species.

• X-Ray Tetra Anatomy and Appearance

The most distinctive feature of the X-Ray Tetra is the translucent layer of skin that covers it's small body, allowing the Fish's backbone to be clearly seen. The scales of the X-Ray Tetra are a silvery-yellowish colour that is very faint, looking almost golden in some lights. The X-Ray Tetra also has a re-tipped tail and strikingly striped dorsal and anal fins that are yellow, black and white in colour. This is a relatively small species of Fish that actually has a bony internal structure known as the Weberian apparatus, which is used in picking up sound waves, and contributes to their acute sense of hearing (this bony structure is also found in many of their relatives). Females are generally slightly larger and rounder than the more slender males, although the two are very similar in appearance.

• X-Ray Tetra Distribution and Habitat

The X-Ray Tetra is found in the Amazonian coastal waters of Brazil, Guiana, Guyana, and Venezuela in South America. They differ greatly from other Tetra species as they are able to tolerate the harder brackish water closer to the coast, as well as their usual freshwater environments. They inhabit clear-water streams and tributaries during the dry season, and with the coming of the rains, the X-Ray Tetra then move into the flooded marshlands where the water is softer and more acidic. It is during the wet season that the X-Ray Tetra breed as they have better water conditions and a higher abundance of food.