Pristella Tetra
Pristella maxillaris
Also known as X-Ray Tetra, Water Goldfinch
Edited by Ivan F. · Reviewed
Beginner verdict
A see-through little tetra with yellow, black and white fins, sometimes called the X-ray fish. It is very peaceful and adaptable to most water, which makes it a dependable beginner choice. It simply cannot compete with boisterous fish, so choose its companions with care.
Care at a glance
- Min tank size
- 14 US gal
- Footprint
- 24 x 12 in
- Temperature
- 72–82 °F
- pH
- 6–7.5
- Hardness
- 2–20 dGH
- Swim zone
- Mid-Water
- Min group
- 6 fish
- Lifespan
- Not well documented
Pristella Tetra care mistakes to avoid
The mistakes beginners most often make with this species.
- Do not buy just one or two. Keep at least 6 fish so they feel secure.
- Avoid boisterous or much larger tank mates, which it cannot compete with.
- Do not keep it under harsh light without plants, or it will spend the day hiding.
- Keep the school together, because a small group becomes nervous and pale.
- Check your tank before you buy. Our sourced minimum is 14 US gallons.
Pristella Tetra tank mates and swim zone
Mid-Water
Spends most of its time in this part of the tank.
Poecilia reticulata
Poecilia wingei
Xiphophorus maculatus
Xiphophorus hellerii
Poecilia sphenops
Trichogaster chuna
Boraras brigittae
Chili Rasbora is small and shy, and is easily outcompeted for food by Pristella Tetra.
Tanichthys albonubes
Their temperature ranges barely overlap, so you will have little room for error.
Betta splendens
Betta often does best alone. Only try this in a larger, planted tank, and watch closely.
Ancistrus cirrhosus
Bristlenose Pleco is much larger than Pristella Tetra and may frighten or even eat it.
Carassius auratus
Goldfish suit cooler water and are not suited to tropical tanks, so Pristella Tetra is a poor match.
Pristella Tetra feeding and care
How to feed
- Feed small flakes and micro pellets, which it takes readily.
- Add small live or frozen foods such as daphnia for the best condition.
- Feed small portions you can see finished within a couple of minutes, because overfeeding fouls the water fast.
Telling males from females
Mature females are usually bigger and noticeably stockier than males.
Plants that suit it
Species facts
- Family
- Characidae
- Native to
- Amazon, Orinoco and coastal Guiana rivers
- Adult size
- 1.8 in (4.5 cm)
- Temperament
- Peaceful
- Social needs
- Schooling/Shoaling (6+)
- Diet
- Micro-Predator
- Water flow
- Gentle
- Substrate
- Any
- Live plants
- Yes - Loves Plants
- Shrimp
- Adult Shrimp Only
- Fin nipping
- None
- Vulnerable to nippers
- No
- Breeding
- Moderate
Pristella Tetra FAQ
What size tank do Pristella Tetras need?
Our sourced minimum is 14 US gallons (54 liters), with a footprint of 60 x 30 cm. A bigger tank is always easier to keep stable.
How many Pristella Tetras should I keep?
Keep at least 6 fish. Bigger groups usually look better and behave more confidently.
What can live with Pristella Tetras?
Good matches on our list include Fancy Guppy, Endler's Livebearer and Platy. Avoid Goldfish.
How long do Pristella Tetras live?
Lifespan is not well documented for this species. Stable water and a good diet help any animal live longer.
Why is it called the X-ray tetra?
Its body is so translucent that you can see its spine and organs through its sides, like an X-ray image.
Where to buy Pristella Tetra
We have not found a store that sells Pristella Tetra under its scientific name yet. We add stores as we confirm them.
Live animals and plants travel by courier. Check the store's live-arrival guarantee, and only buy once your tank has cycled (see how to cycle a fish tank).
Some US states restrict certain species. Check our US state aquarium rules table and your state's own rules before you buy.
Complete the tank
A forgiving setup with room for a small community.
Tank size for this species
At least 14 US gallons (54 L), 60 x 30 cm footprint
Filter
Hang-on-back or large sponge filter
Easy to maintain and strong enough for a community without blasting the fish.
We are still choosing products for this.
Heater
Adjustable heater, about 5 W per gallon: 100 W at 20 gallons, about 150 W at 29
Enough power to hold a stable temperature in most homes. Size up for a cold room.
We are still choosing products for this.
Water Conditioner
Dechlorinator such as Seachem Prime
Tap water contains chlorine or chloramine that harms fish.
Seachem Prime US
Fritz Complete Water Conditioner US
API Betta Water Conditioner US
sera aquatan Spain
Tetra AquaSafe Spain
Maker's page · Sold at Kiwoko · Sold at Tiendanimal · Sold at zooplus.es
Why we chose these (Best Water Conditioner for Betta Fish). Nobody here has used or tested them.
Test Kit
Liquid kit such as API Freshwater Master
Tracks ammonia, nitrite, nitrate and pH while the tank cycles.
API Freshwater Master Test Kit US
API General & Carbonate Hardness Test Kit US
Maker's page · Sold at The Shrimp Farm · Sold at Bulk Reef Supply
sera aqua-test box (Cl) Spain
JBL PROAQUATEST COMBISET Plus NH4 Spain
Why we chose these (Best Test Kit for a Freshwater Aquarium). Nobody here has used or tested them.
Cycle the tank before adding animals. See our guide on how to cycle a fish tank.