X-ray tetras with shrimp

By the Shrimp Tank Hub editorsUpdated Oct 27, 2026Research-based

The X-ray tetra (Pristella maxillaris), also sold as the pristella tetra or water goldfinch, is a small, partly see-through characid with a yellow, black and white dorsal fin and a reddish tail (Seriously Fish, Maidenhead Aquatics, Practical Fishkeeping). It is the only species in its genus and comes from coastal Venezuela, Guyana, Suriname, French Guiana and northern Brazil, where it lives in clearwater streams in the dry season and moves into flooded savannah to spawn when the rains come (Seriously Fish). Almost all fish sold are commercially bred, and a semi-albino "gold" form exists (Seriously Fish, Maidenhead Aquatics).

X-ray tetra at a glance

Will X-ray tetras eat shrimp?

• Adult shrimp: our sources don't test X-rays with shrimp. Aquarium Co-Op's tank-mate guide says tiny-mouthed nano fish pose little threat to full-grown cherry shrimp but warns against medium-sized and larger fish, and Practical Fishkeeping's Nathan Hill personally counts the larger tetras among fish that will eventually eat shrimp. A peaceful tetra of about 1.8 to 2 inches sits between those groups, so in our reading full-grown female cherry shrimp usually fare better than small males and freshly molted shrimp.
• Shrimplets: expect them to be eaten. Seriously Fish says X-rays feed mainly on small invertebrates in nature, and Neale Monks at Practical Fishkeeping says pretty much any active fish, even one as small as a tetra, views hatchling shrimp as food.
• Eggs and berried females: safe while carried. Shrimp hold their eggs under the tail.

In the wild, Practical Fishkeeping's Tai Strietman watched an X-ray picking food from the current and sparring briefly with other small characins over its spot. It is a lively hunter of tiny things, not a grazer. For gentler choices, compare ember tetras with shrimp, green neon tetras with shrimp and black neon tetras with shrimp, or see the full cherry shrimp tank mates list.

Matching the water

Seriously Fish lists 72–82 °F, pH 6.0–7.5 and 2–20 °H, and says hardness is not critical because its home waters change through the flood seasons. Maidenhead Aquatics says it adapts to pH 6.0–8.0. Cherry-type shrimp tolerate 65–85 °F, pH 6.2–8.0 and GH 4–8 (The Shrimp Farm). By our comparison:

• With cherry shrimp: about 74–78 °F, pH 6.5–7.5 and GH 4–8 suits both comfortably. See shrimp tank pH and GH and KH explained.
• With crystal and other Caridina: crystal reds do best at about 68–74 °F (see crystal red shrimp care), mostly below the X-ray's 72 °F minimum, and the shrimplet risk is real. We wouldn't pair them (our reading).

Keep conditions steady at water changes. See shrimp tank water changes and shrimp water parameters.

Tank size and setup

• Size: Seriously Fish suggests a base of at least 24 × 12 in, a 24-inch-long tank or larger.
• Cycled tank: X-rays are hardy, but shrimp are not; start with a mature tank. See how to cycle a shrimp tank.
• Plants and cover: Seriously Fish says X-rays look best in a heavily planted tank and can look washed out in bare setups; Maidenhead Aquatics suggests dark furnishings and plants. For a biotope, Seriously Fish and Practical Fishkeeping suggest river sand, driftwood and leaf litter. Dense moss and stem plants give shrimp places to hide (Aquarium Co-Op). See java moss for shrimp and driftwood and botanicals for shrimp.
• Shrimp-safe intake: a sponge filter or pre-filter keeps shrimplets out of the filter (our suggestion). See shrimp-safe filters.

Keep a real school

Seriously Fish says to buy at least 6 and preferably 10 or more, because it is a shoaling fish that does much better with its own kind. Mature females are bigger and stockier than males (Seriously Fish), and colors improve with age (Maidenhead Aquatics). Practical Fishkeeping's Tai Strietman notes that many shop fish look pale next to wild ones, with weaker red in the tail and yellow in the fins.

Other good tankmates

Seriously Fish suggests other small South American fish such as small tetras, pencilfish, hatchetfish, Corydoras and small Loricariids, plus dwarf cichlids. Practical Fishkeeping and Aquarium Co-Op both say dwarf cichlids hunt shrimp, so leave them out of a shrimp tank. See pygmy corydoras with shrimp, otocinclus with shrimp and marbled hatchetfish with shrimp.

Feeding both

Seriously Fish says X-rays are unfussy and suggests dried flakes and granules with small live and frozen foods such as Daphnia and Artemia. Maidenhead Aquatics adds micro pellets and mosquito larvae. Well-fed fish hunt less, so feed the tetras first, then drop sinking shrimp food in a planted corner (our suggestion). See best shrimp food.

How to add X-ray tetras to a shrimp tank

• Shrimp first. Practical Fishkeeping suggests letting the shrimp colony build up before adding fish, and lots of hiding places and well-fed fish reduce losses.
• Consider bigger shrimp. Neale Monks suggests larger shrimp such as Amanos when the fish are likely to eat babies. See Amano shrimp care.
• Acclimate slowly to your water. See how to drip acclimate.
• Watch shrimp numbers for the first few weeks, especially after molts.
• Quarantine the fish separately. Practical Fishkeeping says many fish medications are not safe for invertebrates. If fish get sick, ask a fish veterinarian or an experienced store about treatment that won't harm the shrimp. See how to quarantine and is copper toxic to shrimp.

Common mistakes

• Treating a 2-inch micropredator like a tiny nano fish.
• Expecting a cherry colony to grow quickly with a school of X-rays hunting the babies.
• Adding dwarf cichlids, a classic X-ray tankmate, to a shrimp tank.
• Keeping only 2 or 3 in a bare tank, where they look pale and stressed.

Track it

Log temperature, pH, GH and TDS on the free Water Parameter Log printable so you can keep the tank in the range both species share.

Frequently asked questions

Will X-ray tetras eat cherry shrimp?

They will eat shrimplets, like any active tetra (Practical Fishkeeping), and Seriously Fish says they feed mainly on small invertebrates in the wild. No source we checked singles them out for eating adults, but give adult shrimp dense cover.

How big do X-ray tetras get?

About 1.8 inches (45 mm standard length) per Seriously Fish, or 5 cm (2 inches) per Maidenhead Aquatics.

What water do X-ray tetras need?

Seriously Fish lists 72 to 82 °F, pH 6.0 to 7.5 and 2 to 20 °H. With cherry shrimp, about 74 to 78 °F and pH 6.5 to 7.5 suits both.

How many X-ray tetras should I keep?

At least 6, preferably 10 or more (Seriously Fish), in a tank with a base of at least 24 by 12 inches.

Are X-ray tetras the same as pristella tetras?

Yes. Pristella maxillaris is sold as the X-ray tetra, pristella tetra or water goldfinch (Seriously Fish, Maidenhead Aquatics).

What shrimp are safest with X-ray tetras?

Larger shrimp such as Amanos, which Neale Monks at Practical Fishkeeping suggests when fish are likely to eat babies.

Sources: Seriously Fish, Pristella maxillaris (X-ray tetra) (only species in the genus; coastal Venezuela, the Guianas and northern Brazil; clearwater streams, flooded savannah for spawning; bred in huge numbers, gold semi-albino form; 45 mm SL; base 60 × 30 cm; looks best heavily planted; 22–28 °C, pH 6.0–7.5, 2–20 °H; micropredator of small invertebrates; flakes, granules, Daphnia, Artemia; very peaceful; groups of 6, preferably 10+; small tetras, pencilfish, hatchetfish, Apistogramma, Corydoras, small Loricariids; females bigger and stockier); Maidenhead Aquatics (fishkeeper.co.uk), X-ray tetra (5 cm; 24–28 °C; pH 6.0–8.0, dH to 25; mostly captive-bred; hardy, peaceful, beginner fish; groups of 6+; dark furnishings and plants; colors improve with age; flake, micro pellets, Daphnia, brine shrimp, mosquito larvae); Practical Fishkeeping, X is for X-ray: visiting a clearwater Brazilian habitat (wild X-rays in Maranhão, Brazil, March 2026: brighter than pale shop fish, drift-feeding in current and sparring with other small characins; simple sand, leaf litter and wood biotope); Aquarium Co-Op, Cherry shrimp tank mates (tiny-mouthed nano fish little threat to adult cherry shrimp; avoid medium to large fish; dwarf cichlids go after shrimp; dense foliage hides babies); Practical Fishkeeping, Can I safely add some shrimp? (any active fish, even a small tetra, sees hatchling shrimp as food; larger shrimp such as Amanos as an alternative); Practical Fishkeeping, What can I keep with shrimp? (larger tetras and barbs likely to eat shrimp in the author's view; dwarf cichlids hunt shrimp; build the colony first; hiding places and well-fed fish reduce losses; many fish medications unsafe for invertebrates); The Shrimp Farm, Red rili shrimp tank set-up and care (cherry-type Neocaridina: 65–85 °F, pH 6.2–8.0, GH 4–8). The shared water zones, shrimp-risk reading and stocking suggestions are our own.