Lambchop rasbora care guide
Also called: Espei rasbora, Lamb chop rasbora, False harlequin rasbora, Espe's rasbora
The lambchop rasbora is a small, peaceful schooling fish with a copper-orange body and a thin black mark shaped like a lamb chop. It's an easy, colorful choice for a planted community tank when kept in a group of 8 or more.
Lambchop rasboras need a tank of at least 15 gallons (57 L), a group of 8 or more, and water at 23–27°C (73–81°F) with a pH of 6–7.5. They grow to about 3.5 cm (1.4 in) and are peaceful.
Plan a tank with lambchop rasborasSee all tank mates
Lambchop rasbora quick facts
| Scientific name | Trigonostigma espei |
|---|---|
| Family | Danionidae |
| Origin | Southern and southeastern Thailand, southwestern Cambodia and Phu Quoc Island, Vietnam |
| Adult size | 3.5 cm (1.4 in) |
| Minimum tank | 15 gallons (57 L), at least 60 cm (24 in) long |
| Temperature | 23–27°C (73–81°F) |
| pH | 6–7.5 |
| Hardness (GH) | 2–10 dGH |
| Group size | 8 or more (schooling fish) |
| Temperament | Peaceful |
| Swims at | Middle |
| Diet | Omnivore |
| Care level | Easy |
| Lifespan | 4–6 years |
| Safe with shrimp? | Mostly (eats baby shrimp) |
| Safe with plants? | Yes |
Tank setup
Keep a group in at least 15 gallons (57 L), ideally in a tank 24 in (60 cm) long. Plant the edges well and leave open swimming space in the middle. A dark substrate, floating plants and soft light bring out their orange color. Moderate filter flow is fine.
How many lambchop rasboras in a tank?
The smallest common tank that suits lambchop rasboras is a 15 gallon. Here is roughly how many fit in each size when they are the only fish, based on adult size and waste output. Leave room if you want tank mates.
| Tank | Lambchop rasboras (alone) |
|---|---|
| 3 gallon | Too small |
| 5 gallon | Too small |
| 10 gallon | Too small |
| 15 gallon | 8–24 |
| 20 gallon | 8–33 |
| 20 gallon long | 8–33 |
| 29 gallon | 8–48 |
| 40 gallon | 8–66 |
| 55 gallon | 8–91 |
| 75 gallon | 8–124 |
| 125 gallon | 8–208 |
What you need for lambchop rasboras
Sized for a 15 gallon tank, the smallest common size that suits a group of 8 lambchop rasboras. For a different tank or a mix of fish, use the stocking calculator for a list sized to your plan.
Tank and equipment
- 15 gallon aquarium (tank or kit) (opens Amazon in a new tab)Bigger tanks are more stable and easier for beginners. How to choose
- Adjustable heater, 50 W (opens Amazon in a new tab)Holds about 77 °F (25 °C) in a room at 65 °F (18 °C). How to choose
- Aquarium thermometer (opens Amazon in a new tab)Check it daily: heaters can fail stuck on or off. How to choose
- Hang-on-back filter rated 60–90 GPH (opens Amazon in a new tab)Community tank: 4–6 times the tank volume per hour. How to choose
- About 35 lb of aquarium gravel (opens Amazon in a new tab)Enough for a layer about 2 in (5 cm) deep. Smooth gravel suits most community fish. How to choose
- Water conditioner (dechlorinator) (opens Amazon in a new tab)Removes chlorine and chloramine from tap water. Seachem Prime is a popular, concentrated choice. How to choose
- Liquid test kit (ammonia, nitrite, nitrate, pH) (opens Amazon in a new tab)Liquid kits are more accurate than strips. The API Freshwater Master Test Kit is the common choice. How to choose
- Gravel vacuum (siphon) (opens Amazon in a new tab)Cleans the gravel and does the water change in one go. How to choose
- LED aquarium light, about 24 in long (opens Amazon in a new tab)Match the light to the tank length. Basic LEDs grow easy plants. How to choose
Food and extras for lambchop rasboras
- Micro pellets or flakes for small fish (opens Amazon in a new tab)Small enough for tetras, rasboras and other nano fish.
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Water parameters
Keep the water at 23–27°C (73–81°F), pH 6.0–7.5 and soft to moderately hard (about 2–10 dGH). Farm-bred fish cope with a wider range than their wild habitat suggests, but avoid very hard, alkaline water. Change part of the water weekly to keep nitrate low.
Best tank mates for lambchop rasboras
These popular species share lambchop rasboras' water needs and temperament. See the full list of 93 good matches.
Betta fish
6.5 cm (2.6 in) · 24–28°C (75–82°F)
Cherry shrimp
3 cm (1.2 in) · 20–27°C (68–81°F)
Nerite snail
2.5 cm (1 in) · 22–27°C (72–81°F)
Guppy
5 cm (2 in) · 22–27°C (72–81°F)
Dwarf gourami
7.5 cm (3 in) · 24–28°C (75–82°F)
Neon tetra
3.5 cm (1.4 in) · 21–25°C (70–77°F)
Panda corydoras
4.5 cm (1.8 in) · 21–25°C (70–77°F)
Bristlenose pleco
12 cm (4.7 in) · 22–26°C (72–79°F)
Avoid keeping lambchop rasboras with
- Angelfish: Angelfish can eat lambchop rasboras: they're small enough to fit in its mouth once it's grown.
- Common goldfish: They need different temperatures: Lambchop rasbora 23–27°C (73–81°F), common goldfish 15–22°C (59–72°F).
- Oscar: Oscar can eat lambchop rasboras: they're small enough to fit in its mouth once it's grown.
- Bala shark: Bala shark can eat lambchop rasboras: they're small enough to fit in its mouth once it's grown.
- Chinese algae eater: Chinese algae eater is aggressive and will bully or injure peaceful lambchop rasboras.
- Convict cichlid: Convict cichlid can eat lambchop rasboras: they're small enough to fit in its mouth once it's grown.
Feeding
In nature they hunt tiny insects, worms and zooplankton. Feed a good flake or micro pellet daily, and add frozen or live daphnia, brine shrimp or bloodworm a few times a week for the best color. Keep portions small enough to be eaten within a couple of minutes.
Behavior
Lambchops are gentle mid-water fish that leave tank mates alone. They school more tightly and color up more in groups of 8–10 or more, and males display to each other without causing harm. Good companions include small tetras, other rasboras, pygmy corydoras, small gouramis and dwarf shrimp. They can share a tank with harlequins, their close cousins.
Breeding
Like harlequins, they stick their eggs to the underside of broad leaves instead of scattering them. Breeding needs soft, acidic water (pH 5.0–6.0) at the warm end of the range, dim light and broad-leaved plants such as cryptocoryne. Remove the adults after spawning, because they eat eggs. Fry hatch in 1–2 days and start on infusoria.
Tips from experienced keepers
- Buy at least 8. A larger group is less skittish and shows deeper orange color.
- They look like small harlequins. Check for the thin, lamb-chop-shaped mark when buying.
- Offer frozen or live food weekly to keep their copper-orange color bright.
- Adult dwarf shrimp are safe with them, but some baby shrimp may be eaten.
Frequently asked questions
What is the difference between lambchop and harlequin rasboras?
Lambchops are smaller and more orange, with a thinner black mark shaped like a lamb chop. Harlequins are pinkish, deeper-bodied and have a broad black triangle. Their care is almost the same.
How many lambchop rasboras should be kept together?
Keep at least 8, and 10 or more is better. In small groups they hide and lose color.
Can lambchop rasboras live with a betta?
Usually, yes. They are calm, short-finned and don't nip, so they make good betta tank mates in a planted tank of 15 gallons (57 L) or more. Watch for the occasional betta that chases everything.
Sources
We checked these references when writing this page. Values are for healthy long-term keeping, not survival limits. Last reviewed 2026-10-13. See our editorial policy.