Pristella Tetra
Pristella maxillaris
Also known as: X-ray tetra, Water goldfinch, Pristella
Quick Facts
- Adult size: 4-4.5 cm (1.6-1.75 inches)
- Minimum tank size: 60 litres (16 gallons)
- Lifespan: 4–6 years
- Temperament: peaceful
- Swimming level: middle
- Diet: omnivore
- Minimum group size: 6
- Difficulty: beginner
Water Parameters
- Temperature: 22–28°C
- pH: 6–8
- Hardness (GH): 89–322 ppm (5–18 dGH)
Values above are general hardness (GH). For carbonate hardness (KH), the buffer that keeps pH stable, see the water parameters guide.
Care Summary
A tough, long-established community tetra named for its translucent, almost x-ray body, through which the silvery swim bladder is visible, set off by bold black-and-yellow flashes on the dorsal and anal fins. Its great virtue is adaptability: where most popular tetras demand soft, acidic water, the pristella tolerates a wide range and is comfortable in the hard, alkaline water that comes out of the tap in Brisbane, Adelaide, and Perth, making it one of the best small schooling fish for Australian keepers who do not want to treat their water. Hardy, peaceful, active, and inexpensive, it is an excellent and undemanding choice for a first community tank. A gold-finned albino form is also widely sold.
Tankmates
A hardy, adaptable schooling tetra and one of the few that genuinely thrives in the hard, alkaline tap water common across much of Australia, which sets it apart from the soft-water-loving neons and rasboras. Keep it in a group of at least six. Peaceful and unproblematic with most community fish of similar size, and its tolerance for harder water makes it a particularly good match for livebearers, danios, and other hard-water community species, as well as the usual soft-water tetras at a compromise hardness. Avoid fin-nippers and anything large enough to eat it. A genuinely flexible community fish.
Compatible with
- Harlequin Rasbora
- Zebra Danio
- Bronze Corydoras
- Bristlenose Pleco
- Cherry Barb
- Honey Gourami
- Otocinclus
- Platy
- Indian Glassfish
- Odessa Barb
Avoid keeping with
- Betta
- Angelfish
- Large Cichlids
- Fin Nippers
- Tiger Barb
Common Problems
- timidity in small groups
- ich
- fin damage from inappropriate tankmates
- washed-out colour in bright, bare tanks
Sources: seriouslyfish.com, fishbase.org · Last updated: 2026-06-20