Boraras rasboras with shrimp
Boraras is a genus of tiny Southeast Asian cyprinids that Practical Fishkeeping says range from just 13–22 mm (0.5–0.9 in). The best-known member, the chili rasbora (B. brigittae), has its own guide: chili rasboras with shrimp. This page covers its relatives: the phoenix rasbora (B. merah), the dwarf or spotted rasbora (B. maculatus), the strawberry rasbora (B. naevus), the exclamation-point rasbora (B. urophthalmoides) and the rarely seen B. micros. Seriously Fish's species pages say all of them can be kept in a planted tank with Caridina and Neocaridina shrimp.
The Boraras species at a glance
| Species | Max size | pH / hardness | Notes |
|---|---|---|---|
| Phoenix rasbora (B. merah) | 0.8 in (20 mm) | 4.0–6.5, 1–5 dGH | Southern Borneo blackwater; red around its dark markings |
| Dwarf/spotted rasbora (B. maculatus) | 1.0 in (25 mm) | 4.0–6.5, 1–5 dGH | The largest; Malaysia, southern Thailand, Sumatra and Singapore peat-swamp streams |
| Strawberry rasbora (B. naevus) | 0.8 in (20 mm) | 5.0–7.0, 1–10 dGH | Southern Thailand; exported only sporadically |
| Exclamation-point rasbora (B. urophthalmoides) | 0.6 in (16 mm) | 6.0–7.0, 1–10 dGH | Thailand, Cambodia and Vietnam; vegetated swamps and paddies; round dark spot near the tail |
| B. micros | 0.5 in (13 mm) | 6.0–7.0, 2–10 dGH | The smallest; rare in the trade |
Sizes, ranges and water values are from the Seriously Fish species pages, which list 68–82 °F for every species. Seriously Fish warns that fish sold as "micros" or "red micros" are usually other Boraras, so ask the seller for the scientific name.
Will Boraras rasboras eat shrimp?
- Adult shrimp: no. Even the largest Boraras is about an inch long, and Seriously Fish describes all of them as very peaceful and timid.
- Shrimplets: some. Seriously Fish calls them micropredators that eat tiny insects, worms and crustaceans in the wild, and Practical Fishkeeping says they do best on small live foods. A just-hatched shrimp is that size. In a tank with lots of moss, owners usually report that a colony still grows (our reading of common hobby reports).
- Eggs and berried females: safe. Shrimp carry their eggs under the tail, and these fish are far too small to bother an adult.
For more on shrimp-safe choices, see cherry shrimp tank mates.
Matching the water
Seriously Fish lists 68–82 °F for all Boraras. Cherry-type shrimp tolerate 65–85 °F, pH 6.2–8.0 and GH 4–8 (The Shrimp Farm). The overlap depends on the species:
- With cherry shrimp: the strawberry and exclamation-point rasboras (pH up to 7.0, up to 10 dGH) overlap best. By our comparison, about 72–78 °F, pH 6.5–7.0 and GH 4–6 fits both. Practical Fishkeeping's author kept Boraras at 77 °F, pH 6.5, and the article notes another breeder had success at pH 7.2–7.4 and about 6 dGH, so the fish adapt to moderate water better than their wild habitat suggests.
- With crystal and other Caridina: the blackwater phoenix and dwarf rasboras (pH 4.0–6.5, 1–5 dGH) suit the soft, acidic water many Caridina keepers already use. See crystal red shrimp care and Caridina vs Neocaridina.
Whatever you choose, change water slowly and keep it stable. See shrimp water parameters, shrimp tank pH and GH and KH explained.
Tank size and setup
- Size: Seriously Fish suggests a base of at least 45 × 30 cm (18 × 12 in), about 11 gallons, for a group. Practical Fishkeeping's author kept groups of six to ten in tanks of about 16–18 × 10 × 10 in.
- Mature tank only: Seriously Fish says never to add Boraras to a biologically immature tank. That suits a shrimp tank, which should be well established anyway.
- Plants and floaters: dense planting and floating plants that dim the light. Seriously Fish suggests driftwood and dried leaf litter as well. Shrimp graze the biofilm on all of it. See best plants for a shrimp tank and java moss for shrimp.
- Gentle filtration: a sponge filter suits both. See shrimp-safe filters.
Keep one species, in a group
Seriously Fish says Boraras should be kept in a group of at least 8 to 10 of one species. In decent numbers they are less nervous, and males show their best colors as they compete for the attention of females. The Seriously Fish pages for the strawberry and exclamation-point rasboras also advise against mixing Boraras species, because they may hybridize. Pick one species per tank.
Feeding both
Practical Fishkeeping says Boraras accept crushed flakes, micro-pellets and frozen foods, but do best on small live foods such as baby brine shrimp, small Daphnia and microworms. Seriously Fish recommends offering small live or frozen food daily. Food that drifts to the bottom feeds the shrimp. Add sinking shrimp food in a separate corner so the fish don't crowd it (our suggestion). See best shrimp food.
Breeding: fish and shrimp in the same tank
Boraras scatter a few eggs at a time among fine-leaved plants and give no parental care (Seriously Fish, Practical Fishkeeping). Practical Fishkeeping says some fry can survive in a mature, well-planted tank. Shrimp will likely eat some fish eggs, and the fish will eat some shrimplets. If you want to raise more fish, move plants with eggs to a separate small tank.
How to add Boraras to a shrimp tank
- Shrimp first. Practical Fishkeeping suggests building up the shrimp colony before adding fish, so they know the hiding places.
- Acclimate slowly. Use a drip, especially if the store water is very soft.
- 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
- Keeping only three or four fish, which makes them hide.
- Mixing two Boraras species in one tank.
- Adding them to a newly set up tank.
- Pairing them with bigger, boisterous fish. Practical Fishkeeping says they then spend most of their time avoiding tankmates.
- Feeding only dry food.
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 phoenix or dwarf rasboras eat shrimp?
Not adult shrimp. Boraras grow to only 0.5 to 1 inch. They will eat some newborn shrimplets, so dense moss helps a colony keep growing.
Can Boraras rasboras live with cherry shrimp?
Yes. Seriously Fish says they can share a planted tank with Neocaridina and Caridina shrimp. For cherries, aim for about 72 to 78 °F, pH 6.5 to 7.0 and GH 4 to 6.
How many Boraras rasboras should I keep?
Seriously Fish recommends a group of at least 8 to 10 of one species.
Can I mix phoenix and chili rasboras?
It is best not to. Seriously Fish warns that Boraras species may hybridize, so keep one species per tank.
What size tank do Boraras need?
Seriously Fish suggests a base of at least 18 by 12 inches, about 11 gallons, and a mature, densely planted tank.
What is the difference between a strawberry rasbora and a chili rasbora?
They are different species. The strawberry rasbora is Boraras naevus from southern Thailand, and the chili rasbora is Boraras brigittae from Borneo. Seriously Fish notes the trade names are often confused.
Sources: Seriously Fish, Boraras maculatus (dwarf rasbora) (25 mm SL; 68–82 °F, pH 4.0–6.5, 1–5 dGH; peat-swamp blackwater; 45 × 30 cm base; never add to an immature tank; micropredator; can live with Caridina and Neocaridina in a planted tank; group of 8–10); Seriously Fish, Boraras merah (phoenix rasbora) (20 mm; pH 4.0–6.5, 1–5 dGH; southern Borneo); Seriously Fish, Boraras naevus (strawberry rasbora) (20 mm; pH 5.0–7.0, 1–10 dGH; southern Thailand; sporadic exports; trade names including "micros"; may hybridize with other Boraras); Seriously Fish, Boraras urophthalmoides (16 mm; pH 6.0–7.0, 1–10 dGH; Thailand, Cambodia, Vietnam swamps and paddies; may hybridize); Seriously Fish, Boraras micros (13 mm; pH 6.0–7.0, 2–10 dGH; rare in the trade); Practical Fishkeeping, Boraras: marvels in miniature (13–22 mm; best with small peaceful fish; groups of six to ten in 16–18 in tanks at 77 °F, pH 6.5; another breeder succeeded at pH 7.2–7.4 and about 6 dH; small live foods best, dry and frozen accepted; no parental care; some fry survive in planted tanks); 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); Practical Fishkeeping, What can I keep with shrimp? (Boraras as shrimp tankmates; build the colony first; many fish medications unsafe for invertebrates); The Shrimp Farm, Shrimp tankmates and compatibility (small peaceful fish with shrimp). The shared water zones are our own comparison.