Serpae tetras with shrimp

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

The serpae tetra, sold as the jewel, red minor, blood or callistus tetra, is a red characid with a black shoulder spot and a black dorsal fin (Seriously Fish). Seriously Fish now lists it as Megalamphodus eques, moved from Hyphessobrycon eques, and Maidenhead Aquatics notes the same move. It ranges through much of the Amazon drainage in Brazil, Peru and Bolivia plus the Río Paraguay (Seriously Fish). Almost all fish sold are commercially bred, and ornamental strains include long-finned, balloon, metallic and fairy-fin forms (Seriously Fish).

Serpae tetra at a glance

Will serpae tetras eat shrimp?

• Adult shrimp: at risk. None of our sources tested serpaes with shrimp, but Seriously Fish lists crustacea in their natural diet and calls them aggressive, and Practical Fishkeeping says they will often dominate and bully less robust species. Aquarium Co-Op advises steering clear of nano fish with a reputation for being fast and hungry. In our reading a group of serpaes will chase and pick at small and freshly molted shrimp even if it can't swallow a grown female.
• Shrimplets: yes. Neale Monks at Practical Fishkeeping says pretty much any active fish, even one as small as a tetra, views hatchling shrimp as food, and serpaes are livelier hunters than most.
• Eggs and berried females: eggs are safe while carried under the tail, but a stressed, harassed female may drop them (our reading).

The nipping is worst when too few serpaes are kept or space is tight (Seriously Fish), so a small tank with a handful of serpaes and a shrimp colony is the worst combination. For gentler fish, compare ember tetras with shrimp, green neon tetras with shrimp and X-ray tetras with shrimp, or see the full cherry shrimp tank mates list.

Matching the water

The water is the easy part. Seriously Fish lists 68–82 °F, pH 5.0–7.5 and 1–15 dGH for farmed fish; Maidenhead Aquatics gives 22–26 °C and pH 6.0–7.5. Cherry-type shrimp tolerate 65–85 °F, pH 6.2–8.0 and GH 4–8 (The Shrimp Farm). By our comparison, about 72–78 °F, pH 6.5–7.5 and GH 4–8 suits both. With crystal shrimp and other Caridina we would not combine them at all (our reading). See shrimp tank pH, GH and KH explained and shrimp water parameters.

Tank size and setup

• Size: Seriously Fish calls a base of 31 × 12 in the absolute minimum, for a group of 12–15 serpaes with no other upper-water species; adding more species needs a larger tank. Practical Fishkeeping told one reader that a 40-litre (11-gallon) tank was too small for a proper group.
• Visual barriers: Maidenhead Aquatics says larger groups in larger tanks with plenty of decor and plants help control the nipping. Seriously Fish suggests sand, wood roots and branches with plenty of shady spots and leaf litter. Dense moss gives shrimp places to hide (Aquarium Co-Op). See java moss for shrimp and driftwood and botanicals for shrimp.
• Cycled tank: start with a mature tank. See how to cycle a shrimp tank.
• Shrimp-safe intake: a sponge filter or pre-filter keeps shrimplets out of the filter (our suggestion). See shrimp-safe filters.

Keep a big school

Seriously Fish says serpaes form loose hierarchies, with rival males constantly sparring, and recommends at least 12 so they are distracted by each other rather than their tankmates. Practical Fishkeeping recommends a bare minimum of ten and warns they may still be a problem with some fish. Females are rounder and a little larger than males (Seriously Fish).

Other tankmates

Seriously Fish says serpaes don't suit very shy, slow-moving or long-finned fish such as many livebearers, cichlids and anabantoids, and Practical Fishkeeping names angelfish, bettas and male guppies as the usual victims of fin-nippers. Better matches are robust, similar-sized open-water characins, hatchetfish, pencilfish and smaller callichthyid or loricariid catfish (Seriously Fish). For a shrimp tank, bottom-dwellers such as otocinclus and corydoras are the safer companions (see their pages).

Feeding both

Maidenhead Aquatics says serpaes eagerly accept most foods and suggests flake, micropellets and small frozen foods such as Daphnia and mosquito larvae. Seriously Fish suggests a quality dried food with freeze-dried bloodworm and Daphnia. Feed the fish well and first, then drop sinking shrimp food in a dense, planted corner (our suggestion). See best shrimp food.

If you still want serpaes and shrimp

• Use bigger shrimp. Neale Monks suggests larger shrimp such as Amanos when fish are likely to eat babies. See Amano shrimp care.
• Shrimp first, in thick cover. Practical Fishkeeping suggests letting the shrimp colony build up before adding fish, with lots of hiding places.
• Acclimate slowly to your water. See how to drip acclimate.
• Have a plan B. If shrimp go missing, move the fish or the shrimp.
• 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

• Buying 3 to 5 serpaes for a small tank, which makes nipping worse.
• Adding long-finned fish such as bettas, angelfish or fancy guppies.
• Buying the long-finned serpae strain, which Practical Fishkeeping says ends up with tatty fins.
• Expecting a breeding cherry colony to survive alongside them.

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 serpae tetras eat cherry shrimp?

They will eat shrimplets, and in our reading they will harass and pick at small adults too. Seriously Fish lists crustacea in their wild diet and calls them aggressive; we rate them a high risk.

Are serpae tetras fin nippers?

Yes. Practical Fishkeeping calls them the most famous fin-nipping tetra, and Seriously Fish says the nipping is worst when too few are kept or space is limited.

How many serpae tetras should I keep?

At least 12 per Seriously Fish, or a bare minimum of 10 per Practical Fishkeeping, in a tank with a base of at least 31 by 12 inches.

How big do serpae tetras get?

About 1.6 inches (40 mm standard length) per Seriously Fish, or 4 cm per Maidenhead Aquatics and Practical Fishkeeping.

What is a good alternative to serpae tetras in a shrimp tank?

Ember tetras, which Maidenhead Aquatics and Practical Fishkeeping both suggest for a similar color without the aggression.

Is the serpae tetra Hyphessobrycon eques?

It was. Seriously Fish now lists it as Megalamphodus eques, and Maidenhead Aquatics notes the same move.

Sources: Seriously Fish, Megalamphodus eques (serpae tetra) (Megalamphodus eques, moved from Hyphessobrycon; Amazon drainage in Brazil, Peru, Bolivia and the Río Paraguay; also sold as jewel, red minor, blood or callistus tetra; long-finned, balloon, metallic, fairy-fin strains; 40 mm SL; base 80 × 30 cm absolute minimum; 20–28 °C, pH 5.0–7.5, 1–15 dGH; likely omnivorous on small invertebrates, crustacea, algae and fruit; notorious aggressive fin-nipper, worst in small groups or tight space; loose hierarchies; at least 12; not for shy, slow or long-finned fish; robust characins, hatchetfish, lebiasinids, small catfish; females rounder); Maidenhead Aquatics (fishkeeper.co.uk), Serpae tetra (4 cm; 22–26 °C; pH 6.0–7.5, dH to 18; community with no long-finned fish; 10+ in larger tanks with decor and plants; red phantom or ember tetra as gentler alternatives; flake, micropellets, Daphnia, mosquito larvae; now in Megalamphodus); Practical Fishkeeping, What can I keep with this bossy fish? (pugnacious, nippy, bullies less robust fish; bare minimum of ten; 40-litre tank too small; 4 cm; ember tetras as a substitute); Practical Fishkeeping, Charge of the bite brigade! (most famous fin-nipping tetra; targets angelfish, bettas and male guppies; keep in large numbers without long-finned fish; long-finned strain has tatty fins); Aquarium Co-Op, Cherry shrimp tank mates (avoid medium to large fish and fast, hungry nano fish; 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; build the colony first; hiding places 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 zone, the high shrimp-risk rating and the stocking suggestions are our own.