Ocellatus shell dweller
A five-centimetre cichlid that lives inside a snail shell, excavates the sand around it into a crater and defends the result against anything that approaches. It fits in a small tank on size and needs floor area rather than volume, which is a distinction that decides whether keeping it works.
Quick profile
- Scientific name
- Lamprologus ocellatus
- Adult size
- 4–6 cm (1.6–2.4 in)
- Lifespan
- 5–8 years
- Temperature
- 24–27 °C (75–81 °F)
- pH
- 7.8–9
- Hardness
- 10–20 °dGH
- Minimum tank
- 60 L (16 US gal)
- Minimum length
- 60 cm
- Swimming zone
- Bottom
- Social
- Harem — at least 3
- Diet
- Micropredator
- Overall confidence
- moderate confidence
What keeping this species involves
Small, hardy, undemanding about food and content in a modest tank provided it is a long one. The requirements are sand, shells and hard water, all of which are easy to supply once known.
Open sand scattered with the empty shells of a large lake snail, each of which is a complete home for one fish.
Identity and names
- Common name
- Ocellatus shell dweller
- Scientific name
- Lamprologus ocellatus
- Family
- Cichlidae
- Order
- Cichliformes
- Class
- Actinopterygii
- Also sold as
- Lamprologus ocellatus, Neolamprologus ocellatus, ocellatus, gold ocellatus, shellie
- Former or synonymous names
- Neolamprologus ocellatus
Name ambiguity
Widely sold as Neolamprologus ocellatus and filed by GBIF's backbone under Lamprologus, which is the placement this catalogue uses. Both names are searchable because the shop label will say the other one.
Adult size and growth
4–6 cm (1.6–2.4 in)
Typical lifespan in an aquarium: 5–8 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
Territory here is measured in the sand around a shell, so the requirement is floor area and shell spacing. A tall tank of the same volume holds fewer territories and produces more conflict.
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: Tanganyikan sand-floor water. The species is tolerant within that range and intolerant of soft acidic water, which dissolves the shells it depends on as well as suiting the fish poorly.
Where these figures come from
Habitat class
Lake Tanganyika
An ancient, enormous, strongly buffered rift lake with the most alkaline water any commonly kept aquarium fish comes from.
Not interchangeable with Malawi. Tanganyika is markedly more alkaline and more mineral-rich, and its temperature is markedly more stable, because the lake is deep enough to be its own thermostat.
- Conductivity
- 570–700 µS/cm
- Flow
- low
- Dissolved oxygen
- near saturation
- Seasonality
- weak
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 | 24–27 °C (75–81 °F) | Stability matters more than hitting an exact figure. |
| pH | 7.8–9 | A stable pH outside the ideal band is usually better than an unstable one inside it. |
| General hardness | 10–20 °dGH | Check your supplier's published figure before choosing species. |
| Carbonate hardness | 12–20 °dKH | Buffering capacity — what stops the pH moving. |
| Minimum volume | 60 L (16 US gal) | A floor, not a recommendation. |
| Minimum footprint | 60 cm long × 30 cm deep | Territory here is measured in the sand around a shell, so the requirement is floor area and shell spacing. A tall tank of the same volume holds fewer territories and produces more conflict. |
| Water flow | low | Match the outflow to this rather than to the filter's rating. |
| Lid required | Recommended | Reduces evaporation and prevents accidents. |
| Structure | Several centimetres of fine sand and at least two empty shells per fish, spaced apart. Escargot shells are the usual substitute for the lake's own and work well. |
Behaviour
- Digs the sand out from around its shell in mouthfuls and spits it clear, building a crater it can see across.
- Retreats into the shell tail-first and reappears facing outward, and will lunge at a hand entering the tank at shell height.
Telling males from females
Males are noticeably larger with a more pointed dorsal fin. Females are smaller and, unusually, are the more aggressive of the two around the shell.
Feeding
Feeds on small invertebrates taken from just above the sand. It rarely ventures far from its shell to eat, so food has to reach the territory rather than the other way round.
- Diet type
- Micropredator
- Staples
- Frozen cyclops, Frozen brine shrimp, Small sinking pellets, Live daphnia
Breeding
- Strategy
- Eggs laid inside the shell and guarded by the female
- Difficulty
- incidental
- Parental care
- guarding
Fry emerge from the shell and stay within centimetres of it. Parents tolerate them until the next spawning.
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 | low | Anything that fits in the mouth is at risk once this species reaches adult size. |
| Adult dwarf shrimp | high | 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.
- A shell it cannot fit inside is not a home. Shells have to be large enough for an adult and there have to be spares, or the fish spends its life displaced.
- Frequently sold as a nano fish on size alone. Five centimetres of Tanganyikan cichlid will hold a third of a small tank against everything else in it, which is not what most nano stocking assumes.
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
- Lake Tanganyika — sandy floors where empty Neothauma snail shells accumulate
- Habitat
- Open sand scattered with the empty shells of a large lake snail, each of which is a complete home for one fish.
What the checklists say
2 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 |
|---|---|---|
| Recorded as present, establishment means not stated | 2 | The source records the species as present and does not say whether it is native or introduced. AquariumHQ does not fill that in. |
No checklist AquariumHQ holds positively calls this species native anywhere, so the native range above rests on AquariumHQ’s own reading of the literature rather than on a cited checklist.
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 | Lamprologus ocellatus | Observed / measured | high confidence | Catalogue of Life; GBIF — Global Biodiversity Information Facility |
| native range | Lake Tanganyika — sandy floors where empty Neothauma snail shells accumulate | Observed / measured | moderate confidence | GBIF — Global Biodiversity Information Facility |
| adult size | 4–6 cm | Aquarium-literature consensus | moderate confidence | AquariumHQ husbandry synthesis |
| lifespan | 5–8 years | Aquarium-literature consensus | moderate confidence | AquariumHQ husbandry synthesis |
| temperature | 24–27 °C | Aquarium-literature consensus | moderate confidence | AquariumHQ husbandry synthesis |
| ph | 7.8–9 pH | Aquarium-literature consensus | moderate confidence | AquariumHQ husbandry synthesis |
| general hardness | 10–20 °dGH | Aquarium-literature consensus | moderate confidence | AquariumHQ husbandry synthesis |
| minimum tank volume | ≥ 60 L | AquariumHQ editorial position | moderate confidence | AquariumHQ husbandry synthesis |
| minimum tank length | ≥ 60 cm | AquariumHQ editorial position | moderate confidence | AquariumHQ husbandry synthesis |
| carbonate hardness | 12–20 °dKH | Aquarium-literature consensus | moderate confidence | AquariumHQ husbandry synthesis |
| minimum group size | ≥ 3 | 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 checkableLimited evidence — treat with caution.
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. 2 distribution statements held, and not one of them states an establishment means. Presence without native-or-introduced is not a native-range claim, so this stays below requirement rather than being read as one.
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.
carbonate 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 group sizeAquariumHQ'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: group size — 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: 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 adult dwarf shrimp, which decides what can share the tank.
- 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.
- 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
Each fish holds a shell and the sand immediately around it. Disputes are over shells rather than over the tank, so supplying more shells than fish is the single most effective thing a keeper can do.