X-Ray Tetra

About

The X-ray tetra (Pristella maxillaris) gets its name from the translucent body that lets you see the spine and internal organs right through the flesh. A look that's genuinely unlike most other tetras you'll encounter. Splashed across that glassy body are bright yellow, black, and white markings on the dorsal and anal fins, which really pop when you have a good-sized group moving together. In the wild, these fish inhabit slow-moving, heavily vegetated coastal waters across a wide stretch of South America, from the Amazon and Orinoco basins to the river drainages of the Guianas, where they feed on small invertebrates and insects. In the aquarium they're equally unfussy, accepting most foods without complaint. Temperamentally, they're as gentle as tetras come. Easy prey for nippy or boisterous tankmates, so choose their companions with care. Small South American species make obvious partners: pencilfish, hatchetfish, Corydoras, Apistogramma, and other peaceful tetras all work well. Keep them in groups of at least six, though ten or more is where they really settle and behave naturally. Interestingly, other fish in the tank often take behavioral cues from them. A tightly bunched school signals danger, a scattered group signals calm. Spawning is achievable but raising the tiny fry demands a dedicated setup and some patience.