Multi shell dweller

Quick facts

Adult size

4 cm

Lifespan

can live up to 5 years

Tank zone

bottom

Temperament

semi-aggressive

Difficulty

beginner

Water parameters

Temperature

24–27°C

pH

7.8 to 9.0

Hardness

12 to 25 dGH

Tank requirements

Minimum volume

40 L

Minimum length

45 cm

Flow

low

Lighting

any

Substrate

sand

Hiding spots

needed

Feeding

Diet: omnivore, feeds primarily at the bottom.

Micro pellets, crushed flake, frozen baby brine shrimp. Tiny mouths; food needs to be small enough to fit. Will scavenge anything that sinks to the bottom.

Compatibility

• The smallest cichlid commonly kept. A colony in a 40 L tank is one of the most fascinating setups in the hobby
• Need empty snail shells (Neothauma tanganyicense in the wild; escargot shells from the grocery store work fine). Each fish claims a shell and defends it aggressively against neighbors
• Colonies self-regulate; dominant pairs breed, subordinates wait. Population grows steadily and they'll fill whatever space you give them
• Sand substrate is mandatory. Multis bury and unbury shells constantly; gravel prevents this behavior and stresses them
• Not compatible with anything that threatens the shells. Larger cichlids, loaches, and catfish that investigate shells will be attacked by fish a tenth their size

Habitat

Endemic to Lake Tanganyika's southern basin. Found in massive shell beds: fields of empty Neothauma snail shells covering the sandy lake floor at 5–15 m depth. Each fish lives inside a single shell. The smallest known cichlid in Lake Tanganyika. Unlike most cichlids, multis are colonial and tolerate neighbors at very close range as long as each fish has its own shell.

Breeding

Breeds readily in captivity. Males defend a cluster of empty snail shells (Neothauma tanganyicensis shells are the natural substrate; escargot shells from a grocery store work). Females occupy individual shells and lay 5-15 eggs inside. The male fertilizes and the female guards. Fry emerge from the shell as miniature adults. Colonies establish a hierarchy and breed continuously. One of the most fascinating breeding behaviors in freshwater fish.

Common problems

Need appropriate shells. Without them, they can't breed or feel secure. Provide 2-3 shells per fish. The substrate must be sand so they can bury and rearrange shells (they do this constantly). Hard, alkaline water is required (pH 7.5-9.0, GH 10-25) to match Lake Tanganyika conditions. Very small (3–5 cm) but surprisingly aggressive for their size; they defend shell clusters fiercely.

Bioload

Bioload coefficient: 1.5 (tiny cichlid; bioload per fish is negligible but colonies grow fast).

Bioload coefficients are calibrated against the neon tetra as the anchor (1.0). See the methodology page for the formula and how each value was derived.

Further reading

• How to cycle a fish tank
• Stocking ideas by tank size