X-Ray Tetra Fish

X-Ray Tetra Fish

Size

They can reach 4 – 5cm. Typically they weigh only a few grams. They will be between 1.25 – 2.5 cm in height.

Habitat and Distribution

They inhabit slow-moving coastal rivers, tributaries, and flooded marshlands. X-ray tetras originate from South America, specifically the Amazon and Orinoco River basins in Brazil, Venezuela, Guyana, and Suriname.

Age

They can live up to 3 – 5 years.

Diet

They are omnivorous micro-predators, feeding primarily on small invertebrates, such as aquatic insect larvae, worms, and tiny crustaceans. Their diet is supplemented with algae and plant matter found in their vegetated, tropical habitat.

Groups and Breeding

They breed during the rainy season by scattering 300–400 eggs among submerged vegetation. They are not solitary; rather, they live in large groups to enhance their safety and reduce stress. 

Threats

The IUCN has listed this species as Least Concern, however in the wild, they are still threatened by habitat loss due to Amazonian deforestation, water pollution from industrial activity, and climate-driven changes to their seasonal environments. They face predation from larger fish, birds, snakes, and frogs, while their reliance on specific floodplains makes them vulnerable to ecosystem shifts.

Interesting Facts

One of the most fascinating features of this small fish is a bony structure inside its body known as the Weberian apparatus. This unique structure is seen in other related species and allows for sound waves to travel through their vertebrae and detected by their inner ear.

The X-Ray Tetra Fish During Your Day Out in Kent

The X-Ray Tetra Fish can be found in our Reptile House. Their tanks are just in the window of the Reptile Kitchen. They share this home with a number of other reptiles and amphibians including White’s Tree Frogs, Spectacled Caimans and various Snakes.