X-ray Tetra Identification Guide
Spot the x-ray tetra by its nearly transparent body that reveals its internal skeleton and swim bladder.
Read the full X-ray Tetra encyclopedia entry →
Key identification features
- Small, slender body about 1.6 inches (4 cm) long that is largely translucent, revealing the spine and swim bladder
- Faint golden-olive sheen along the back with silvery sides
- Dorsal, anal, and pelvic fins marked with a bold black-and-yellow banded pattern
- Caudal fin is clear to pale yellow, without dark markings
- No lateral stripe, unlike many other small tetras
- Overall body shape is fairly deep and rounded compared with slimmer see-through species
Common look-alikes
- Glass bloodfin tetra: also translucent, but has an all-clear body with a red-tinged tail rather than banded yellow-black fins.
- Glowlight tetra: shows a solid horizontal orange stripe, a mark the x-ray tetra never carries.
- Penguin tetra: opaque silvery body with a bold diagonal black stripe, easily told apart from the see-through x-ray tetra.
Where you'll see one
Native to coastal river systems, floodplains, and brackish-tinged estuaries of Venezuela, Guyana, and the lower Amazon and Orinoco basins, schooling in open, sluggish waters and tolerating a wider salinity range than most tetras.
Frequently asked questions
What makes the x-ray tetra easy to recognize at a glance?
Its body is see-through enough to reveal the backbone and swim bladder, unlike almost any other common tetra.
How do I tell it apart from a glass bloodfin tetra?
Look at the fins: x-ray tetras have bold black-and-yellow banding, while glass bloodfin tetras have plain fins with a reddish tail.