Green Texas cichlid
A pearl-spotted cichlid from north-eastern Mexico, closely related to the Texas cichlid and distinguished by larger, more irregular spangles. It is one of the few American cichlids that genuinely wants hard alkaline water, which makes it an unusual candidate for a hard-water tank.
Quick profile
- Scientific name
- Herichthys carpintis
- Adult size
- 18–25 cm (7.1–9.8 in)
- Lifespan
- 8–12 years
- Temperature
- 20–28 °C (68–82 °F)
- pH
- 7–8.4
- Hardness
- 10–25 °dGH
- Minimum tank
- 350 L (92 US gal)
- Minimum length
- 150 cm
- Swimming zone
- Bottom
- Social
- Pair
- Diet
- Omnivore
- Overall confidence
- moderate confidence
What keeping this species involves
Hardy, tolerant of cool water and easy to feed. The constraints are size, digging and a temperament that needs planning for rather than managing.
Lowland rivers and lagoons with sandy floors, in hard alkaline water that is cool by tropical standards in winter.
Identity and names
- Common name
- Green Texas cichlid
- Scientific name
- Herichthys carpintis
- Family
- Cichlidae
- Order
- Cichliformes
- Class
- Actinopterygii
- Also sold as
- Herichthys carpintis, Cichlasoma carpintis, lowland cichlid, pearlscale cichlid
- Former or synonymous names
- Cichlasoma carpintis
Adult size and growth
18–25 cm (7.1–9.8 in)
Typical lifespan in an aquarium: 8–12 years. Almost every animal sold in a shop is a juvenile, so the tank has to suit the size in the first line rather than the size in the bag.
Shape, which is what the compatibility engine reads instead of length alone: deep-bodied with a moderate. Assigned from what is typical of Cichlidae, not examined for this species.
Water and tank requirements
A large digging cichlid that claims a section of floor. The length is what leaves floor that is not claimed.
Temperature (°C)
Scale: 0 to 36 °C.
pH (pH)
Scale: 4 to 9.5 pH.
Hardness (°dGH)
Scale: 0 to 30 °dGH.
Why these ranges: The Pánuco system is hard and alkaline, and this species is one of the very few Central American cichlids for which hard water is the native condition rather than a tolerance. The cool lower bound reflects a genuine winter drop in its range.
Where these figures come from
Habitat class
Hard alkaline water
Water draining limestone, gypsum or volcanic mineral — Central American rivers, karst springs, hard-water lakes.
These species are usually easy in hard tap water and difficult in the soft, acidic water the hobby treats as the default. The commonest failure is the keeper softening water that did not need softening.
- Conductivity
- 300–900 µS/cm
- Flow
- moderate
- Dissolved oxygen
- moderate
- Seasonality
- moderate
These are figures for the KIND of water body, not measurements of this species. They are AquariumHQ’s summary of the general limnology and are given wide because the water is.
- TemperatureReasoned on this record
- This record states its own reason for this band. See the water section.
- pHReasoned on this record
- This record states its own reason for this band. See the water section.
- General hardnessReasoned on this record
- This record states its own reason for this band. See the water section.
| Requirement | Value | Notes |
|---|---|---|
| Temperature | 20–28 °C (68–82 °F) | Stability matters more than hitting an exact figure. |
| pH | 7–8.4 | A stable pH outside the ideal band is usually better than an unstable one inside it. |
| General hardness | 10–25 °dGH | Check your supplier's published figure before choosing species. |
| Minimum volume | 350 L (92 US gal) | A floor, not a recommendation. |
| Minimum footprint | 150 cm long × 50 cm deep | A large digging cichlid that claims a section of floor. The length is what leaves floor that is not claimed. |
| Water flow | moderate | Match the outflow to this rather than to the filter's rating. |
| Lid required | Recommended | Reduces evaporation and prevents accidents. |
| Structure | Sand, rock and wood, all of it stable. This species digs more than most and will undermine anything not resting on the base of the tank. |
Behaviour
- Moves substrate constantly, building and demolishing pits across the tank floor.
- Both sexes change to a high-contrast breeding pattern within hours of spawning, and revert equally quickly when the brood is lost.
Telling males from females
Males are larger with a nuchal hump and longer fins. Breeding females develop a strongly contrasting dark and white pattern that males do not match.
Feeding
Takes invertebrates, plant material and detritus from the substrate. A pellet with some vegetable content suits it better than a pure carnivore diet.
- Diet type
- Omnivore
- Staples
- Sinking cichlid pellets, Frozen krill, Earthworm, Blanched pea
- Avoid
- Mammalian meat
Breeding
- Strategy
- Adhesive eggs on a cleaned rock, guarded by both parents
- Difficulty
- straightforward
- Parental care
- guarding
Tankmates and compatibility
Assessments are derived from stored traits by the compatibility engine, with the reasoning shown. A verdict is a statement about probability, not a guarantee — individual temperament can override it.
| Towards | Risk | What it means |
|---|---|---|
| Small fish | near-certain | Anything that fits in the mouth is at risk once this species reaches adult size. |
| Adult dwarf shrimp | near-certain | Cover reduces losses but rarely prevents them where the risk is high. |
| Shrimplets | near-certain | Determines whether a shrimp colony can grow rather than merely persist. |
| Snails | low | Applies to snails you wanted as well as snails you did not. |
| Long or trailing fins | occasional | Fin damage is an entry point for secondary infection. |
| Plants | uproots | Tough species such as Anubias and Java fern survive most grazers. |
Any pair in the catalogue can be assessed with the compatibility checker.
Welfare considerations
Points where the way this species is commonly sold or kept differs from what it actually needs.
- Sold interchangeably with the Texas cichlid, which is a different species from a different drainage. The names on shop labels do not distinguish them and the spot size is the practical clue.
- Hybridised extensively in the trade, including into the ornamental strains sold as flowerhorns. A fish of uncertain parentage may not follow this record's size or temperature figures.
Problems to watch for
Most problems in a tank containing this species are general rather than species-specific. Start with the troubleshooting index and work from the observation rather than from a guess at the cause.
What AquariumHQ does not yet hold
Species-level disease susceptibility is modelled in the graph and is not yet populated. Health pages will not be published until each condition has veterinary sourcing, because health content written without evidence is the most harmful thing this product could publish. The gap is recorded in the coverage report.
Where it comes from
- Native range
- North-eastern Mexico — the Pánuco and Tamesí drainages of Tamaulipas and Veracruz
- Habitat
- Lowland rivers and lagoons with sandy floors, in hard alkaline water that is cool by tropical standards in winter.
What the checklists say
6 distribution statements retrieved from GBIF checklists. Establishment means is reproduced from the source where it states one, and left unstated where it does not — a record of presence is not a record of origin.
| Status | Places | What this means |
|---|---|---|
| Native | 1 | A checklist states the species occurs here naturally. |
| Introduced | 2 | A checklist states the species arrived here with human help. That is not a statement that it is established, harmful or illegal. |
| Recorded as present, establishment means not stated | 3 | The source records the species as present and does not say whether it is native or introduced. AquariumHQ does not fill that in. |
Evidence
Every stored value with the kind of support behind it and where to check it. Evidence type and confidence are separate axes: an editorial position held confidently and a measurement held tentatively are different things.
| Claim | Value | Evidence type | Confidence | Source |
|---|---|---|---|---|
| scientific name | Herichthys carpintis | Observed / measured | high confidence | Catalogue of Life; GBIF — Global Biodiversity Information Facility |
| native range | North-eastern Mexico — the Pánuco and Tamesí drainages of Tamaulipas and Veracruz | Observed / measured | moderate confidence | GBIF — Global Biodiversity Information Facility |
| adult size | 18–25 cm | Aquarium-literature consensus | moderate confidence | AquariumHQ husbandry synthesis |
| lifespan | 8–12 years | Aquarium-literature consensus | moderate confidence | AquariumHQ husbandry synthesis |
| temperature | 20–28 °C | Aquarium-literature consensus | moderate confidence | AquariumHQ husbandry synthesis |
| ph | 7–8.4 pH | Aquarium-literature consensus | moderate confidence | AquariumHQ husbandry synthesis |
| general hardness | 10–25 °dGH | Aquarium-literature consensus | moderate confidence | AquariumHQ husbandry synthesis |
| minimum tank volume | ≥ 350 L | AquariumHQ editorial position | moderate confidence | AquariumHQ husbandry synthesis |
| minimum tank length | ≥ 150 cm | AquariumHQ editorial position | moderate confidence | AquariumHQ husbandry synthesis |
Last reviewed 2026-08-10. Values labelled as an aquarium-literature consensus are AquariumHQ editorial positions rather than measurements — see how evidence is handled.
Why we say this
What each figure on this page rests on, and how far that is from being independently established.
Every figure on this page has a provenance. Open any claim to see what AquariumHQ holds for it, which sources say what, and what a claim of that kind actually needs. Different claims need different evidence: an accepted scientific name is settled by one authority, while a legal restriction needs a current primary instrument. A single source is often the right answer rather than a thin one.
scientific nameAquariumHQ's own position, externally checkableBased on a verified authoritative source.
AquariumHQ's own position on a claim an external source could support.
What this kind of claim needs: accepted scientific name and classification — 1 authoritative source in an appropriate context. Checked against gbif on 2026-08-29. One authoritative backbone is what this class requires.
What would improve this: Go and read a source. This is reachable and has not been reached.
native rangeAquariumHQ's own position, externally checkableBased on a verified authoritative source.
AquariumHQ's own position on a claim an external source could support.
What this kind of claim needs: where the species occurs — 1 authoritative source in an appropriate context. 6 distribution statements held from GBIF checklists — native in 1, introduced in 2 countries. Establishment means is reproduced from the source, never inferred from occurrence.
What would improve this: Go and read a source. This is reachable and has not been reached.
adult sizeAquariumHQ's own position, externally checkableAquariumHQ's own position, derived from evidenced inputs.
AquariumHQ's own position on a claim an external source could support.
What this kind of claim needs: size a well-kept specimen reaches — no external source is required, provided AquariumHQ shows its reasoning. No external source is required for this class. AquariumHQ's position stands on its stated reasoning.
What would improve this: Go and read a source. This is reachable and has not been reached.
lifespanAquariumHQ's own position, externally checkableAquariumHQ's own position, derived from evidenced inputs.
AquariumHQ's own position on a claim an external source could support.
What this kind of claim needs: what aquariumhq advises for keeping — no external source is required, provided AquariumHQ shows its reasoning. No external source is required for this class. AquariumHQ's position stands on its stated reasoning.
What would improve this: Go and read a source. This is reachable and has not been reached.
temperatureAquariumHQ's own position, externally checkableAquariumHQ's own position, derived from evidenced inputs.
AquariumHQ's own position on a claim an external source could support.
What this kind of claim needs: what aquariumhq advises for keeping — no external source is required, provided AquariumHQ shows its reasoning. No external source is required for this class. AquariumHQ's position stands on its stated reasoning.
What would improve this: Go and read a source. This is reachable and has not been reached.
phAquariumHQ's own position, externally checkableAquariumHQ's own position, derived from evidenced inputs.
AquariumHQ's own position on a claim an external source could support.
What this kind of claim needs: what aquariumhq advises for keeping — no external source is required, provided AquariumHQ shows its reasoning. No external source is required for this class. AquariumHQ's position stands on its stated reasoning.
What would improve this: Go and read a source. This is reachable and has not been reached.
general hardnessAquariumHQ's own position, externally checkableAquariumHQ's own position, derived from evidenced inputs.
AquariumHQ's own position on a claim an external source could support.
What this kind of claim needs: what aquariumhq advises for keeping — no external source is required, provided AquariumHQ shows its reasoning. No external source is required for this class. AquariumHQ's position stands on its stated reasoning.
What would improve this: Go and read a source. This is reachable and has not been reached.
minimum tank volumeAquariumHQ's judgement — no authority publishes thisAquariumHQ's own position, derived from evidenced inputs.
No external authority publishes this. The rationale carries the reasoning.
What this kind of claim needs: minimum tank size — no external source is required, provided AquariumHQ shows its reasoning. No authority publishes this. AquariumHQ derives it, and the derivation is recorded with its inputs and assumptions.
What would improve this: Keep the rationale current. There is no source to find.
minimum tank lengthAquariumHQ's judgement — no authority publishes thisAquariumHQ's own position, derived from evidenced inputs.
No external authority publishes this. The rationale carries the reasoning.
What this kind of claim needs: minimum tank size — no external source is required, provided AquariumHQ shows its reasoning. No authority publishes this. AquariumHQ derives it, and the derivation is recorded with its inputs and assumptions.
What would improve this: Keep the rationale current. There is no source to find.
Guides relevant to this species
Chosen from this record's own traits rather than listed on every page.
- Predator and prey sizeIt takes fish that fit in its mouth, and its mouth grows with it.
- Territorial behaviourIt defends ground, and the shape of what it defends decides the tank more than the volume does.
- Scientific and trade namesThis species has been published under more than one accepted name.
- Wild conditions and aquarium recommendationsThe water band on this page is an AquariumHQ position with a stated reason, not a measurement of a river.
- Rehoming an animal you can no longer keepThis animal reaches 25 cm. Most of the difficult rehoming cases are fish sold small that were always going to become impossible.
- How to read a compatibility verdictThis animal is recorded as nipping fins, which is one of the few compatibility factors with real reports behind it.
Group size and social behaviour
Pairs bond and defend jointly. Outside a pair, adults of this species do not share a tank peaceably.