Ember Tetra Tank Mates: Best Fish, Shrimp and What to Skip

Museum records from 11 wild ember tetra collections list the penguin tetra in 10 of them and a pencilfish in none. Most tank mate lists still lead with pencilfish, and the pairing works anyway. In a tank, feeding layer, water and mouth size decide compatibility.

An ember is a 20 mm mid-water micropredator from soft, clear floodplain water. Good ember tetra tank mates feed in a different layer and live at 20 to 28 °C in water of 1 to 10 dGH. Their mouths must also be too small to take a 2 cm fish. Breeders add a fourth test, which is who eats whose fry. Tank size, water and diet for the embers themselves are in the ember tetra care guide.

Ember tetra tank mates compared

Verdicts assume a group of at least 10 embers, a planted tank of 60 cm or more for mixed stocking, and soft water. Shared water is the overlap between the companion’s range and the ember’s 20 to 28 °C, pH 5.0 to 7.0 and 1 to 10 dGH.

The four tests behind every verdict

Feeding layer

Embers hold the middle and upper water and take food as it sinks. Companions that feed at the surface or on the substrate meet them only at feeding time. A Japanese keeper reports that lampeyes that had always hidden in the plants came to the front once embers were added, drawn out by a calm shoal in open water.

Two mid-water shoals in a 60 cm tank share one strip of water. A lone ember joined a lambchop rasbora shoal in a German tank, and a French group merged straight into a rasbora school. Both cases mean the ember group was too small.

Shared water

Embers come from clear floodplain lagoons and backwater channels of the Rio Araguaia. The nearest measured lakes run pH 5.2 to 7.9 at 15 to 35 µS/cm. Tannins suit embers, but they are not blackwater specialists. A tank pushed toward pH 5 for blackwater companions runs embers at the acidic edge of their range.

Several small fish only look compatible. Celestial pearl danios want pH 6.5 to 7.5, GH 5 to 15 and no leaf litter. Crystal Red shrimp top out near 24.5 °C, and Endlers want 15 to 35 dGH. All three survive in an ember tank without thriving at its best settings.

Mouth size and feeding speed

An ember is 20 mm long, so any fish that can swallow 2 cm of prey will eventually try. Adult angelfish reach 150 mm and eat small tetras. Speed causes the opposite problem, since embers eat fast. One Japanese keeper watched them clear the otocinclus wafers. Feed slow species first, or after lights out.

Fry

Embers scatter their eggs and eat them unless the eggs are protected. Adults seldom hunt free-swimming fry but take what they find. Guarding parents change the outcome. A German keeper’s 60 embers failed to dent a ram pair’s brood, while Parosphromenus breeders warn that embers will hunt unguarded licorice gourami fry.

Ember tetras with shrimp and snails

Adult shrimp are safe and shrimplets are not. Keepers in Germany, Poland, the Czech Republic, Russia and Korea describe the same pattern, with embers ignoring adults and picking off newborns they can catch. Results run from total loss to colonies that keep growing. Five embers in one Polish tank left “not a single baby” red cherry alive. Five embers in a Bangkok tank lived among cherry shrimp breeding too fast to count. One shrimp-forum keeper has run embers with red cherries for more than five years.

Cover decides most of the difference. Dense flame or Java moss, floating roots and well-fed embers keep losses small. Run tanks with Caridina bee shrimp at 22 to 24 °C, the only band both species share. More species are rated in the shrimp-safe fish guide.

Snails struggle in ember water. Nerites, mystery snails and Malaysian trumpet snails need pH above 7 for long-term shell health. At pH 6 their shells erode slowly unless a calcium source is added. Giant ramshorns (Marisa) eat plants, and assassin snails eat shrimplets. Dwarf crayfish can turn on the fish too. One Korean keeper’s mini orange crayfish grabbed at tetras with its claws.

Fish to skip, and the real reason

Three famous “nippers” fail for other reasons. Seriously Fish says silver tip tetras lose their nippiness in a proper group, though they still want harder water. Penguin tetras nip only when kept in small numbers. Odessa barbs are peaceful but want cool, hard water.

The dwarf gourami figure most often quoted is wrong. Seriously Fish states that 22% of dwarf gouramis from Singapore carry iridovirus. The 2006 study behind it found 22% infection among gouramis that were already sick in Sydney shops.

Ember tetras with a betta or dwarf cichlids

Betta reports split cleanly by source. Seriously Fish advises keeping bettas alone. Aquarium Co-op ranks embers among the best betta tank mates. A UKAPS keeper’s embers survived a betta but hid constantly, and a Brazilian author sets 40 L as the floor. The deciding factor is the individual betta, so a spare tank must be ready before the embers go in.

Dwarf cichlids are safer for embers than their reputation suggests. Embers are the standard dither fish for Apistogramma, and a German keeper’s macmasteri grew bolder once 100 embers shared the tank. The risk is a brooding female, and one female A. cacatuoides killed a tetra that kept entering her brood territory. Rams need 27 °C or more, which is the top of the ember range.

Hidden gems from the ember’s own river and beyond

Museum collections hold 11 dated wild samples of embers. Every other fish caught at the same spots in the same years gives the ember’s real neighbours. The penguin tetra appears at 10 sites, Ramirezella pyrophthalma at 8 and Hyphessobrycon moniliger at 5. A 2025 survey of the ember’s headwater streams counted 596 Aspidoras poecilus, more than any other catfish.

Several of these natives are missing from Brazil’s 2012 list of fish permitted for ornamental collection, including the Araguaia cory and Laetacara araguaiae. Buy captive-bred stock of these species.

Ember tetra claims the evidence does not support

Five stocking plans for ember tetras

Leaf litter decides more about ember fry than any tank mate does. One German keeper runs RO water, peat and leaf litter with Apistogramma, neons and shrimp. Embers there breed “as if they were guppies” on the infusoria that grow in the leaf piles. Fry that elsewhere need a breeding setup appear there on their own.

Sources

• Seriously Fish: Hyphessobrycon amandae
• Catalog of Fishes: Hyphessobrycon amandae (Géry & Uj, 1987)
• GBIF: ember tetra museum specimens (MZUSP, MCP, UFRGS)
• Lima et al. 2025, headwater fish of the Araguaia and Mortes basins, Oecologia Australis
• Ferreira et al. 2011, fish of Cantão State Park, Biota Neotropica
• IBAMA Instrução Normativa Interministerial nº 01/2012, Anexo I
• Loiselle 2020, Laetacara araguaiae, AMAZONAS
• Bleher, miniature fishes from South America, Practical Fishkeeping
• PlanetCatfish: Hoplisoma araguaiaense
• Seriously Fish: Barboides gracilis
• Seriously Fish: Danio margaritatus
• Parosphromenus Project forum: Compatibility
• Go et al. 2006, iridovirus in dwarf gourami, Molecular and Cellular Probes
• Rimmer et al. 2015, dwarf gourami iridovirus in imported ornamental fish, Preventive Veterinary Medicine
• Saxby et al. 2010, group size and welfare in four fish species, Applied Animal Behaviour Science
• The Shrimp Farm: Crystal Red shrimp care