Care guide · Freshwater · fish

Similis shell-dweller care

Neolamprologus similis

Photo: Yvonne Berzentei (Turkans), CC BY-SA 3.0; crop/image adjustments by MKOliver; resized. Photo: Yvonne Berzentei (Turkans); cropped/adjusted derivative by MKOliver · Source · CC BY-SA 3.0Resized and compressed; no cropping or colour changes.

The Similis shell-dweller (Neolamprologus similis) is a small Lake Tanganyika cichlid whose life centres on empty snail shells. Each fish defends a small area around its shell, which also serves as shelter and a breeding chamber. Seriously Fish gives 40 litres and a 45 cm tank length for a pair; a colony needs substantially more room. Set up fine sand and more empty shells than fish, and keep the hard, alkaline water stable. The layout must let subordinate fish retreat, so the small-volume figure applies only to the stated pair, not a colony.

Plan your aquarium →

At a glance

Temperature: 24–27 °C
pH: 7.5–8.4
GH: 8–25 °dGH
Aquarium length: At least 45 cm
Minimum aquarium volume: At least 40 L
Adult size: Up to 4.5 cm
Group size: At least 2 individuals
Temperament: Territorial

About this species

Neolamprologus similis was described by Büscher in 1992 and belongs to the family Cichlidae. It resembles N. multifasciatus but has additional dark bars on the head and neck. Published sizes use different measurements: Seriously Fish reports a maximum standard length of 4.5 cm, excluding the tail fin, while FishBase reports up to 5 cm total length for male or unsexed fish and 3.5 cm total length for females. These measurements should not be compared directly.

Natural habitat

The species is endemic to Lake Tanganyika in East Africa. FishBase records it from the southern lake in Tanzania and the Democratic Republic of the Congo. Similis is associated with soft shore substrates where empty snail shells accumulate; shells serve as refuge, breeding chamber and centre of a small territory. In an aquarium, open sand and enough suitable shells matter more than dense planting.

Aquarium and layout

Seriously Fish considers a 45 × 30 × 30 cm tank, about 40 litres, sufficient for one pair. That minimum does not apply to a colony, which needs more floor area and space; the reviewed sources do not establish an exact colony volume. Use fine sand and distribute substantially more empty snail shells than fish. This species digs less deeply than some other shell-dwellers. Secure heavy rocks against undermining and leave shell areas arranged so subordinate fish can retreat.

Water conditions

Seriously Fish gives 24–27 °C, pH 7.5–9.0 and GH 8–25 dGH for care. FishBase lists broader ecological ranges of 23–28 °C, pH 7.4–8.4 and hardness 7–30 dH. Because the pH upper limits differ, this guide uses the overlap, 7.5–8.4, as a conservative reference; it is not a reason to alter stable water artificially. Test regularly and avoid rapid swings. The reviewed evidence does not support a separate KH target.

Behaviour and group size

Similis often lives in colonies, but it is not simply a peaceful shoaling fish. Individuals vigorously defend their shells and immediate surroundings, and males may chase one another. Provide many shells and visual breaks. A pair fits the cited smaller setup; a colony needs extra floor space and careful social planning, with more females than males as Seriously Fish advises. Other tankmates are not an automatic match. The source mentions smaller rock-dwelling Julidochromis and open-water Cyprichromis as possibilities, but these require a larger aquarium and individual compatibility assessment. The fish may deliver a venomous defensive bite to intruders; this does not establish dangerous human envenomation, but do not put fingers into occupied shells.

Feeding

In nature the species eats small invertebrates such as copepods, ostracods and insect larvae, as well as algal strands and organic matter. FishBase records these in stomach contents; Seriously Fish recommends live and frozen foods as the bulk of the diet. Fine dried food may be accepted but should not be the sole food. Offer small portions that can be collected near the bottom and ensure dominant fish do not monopolise them. No suitable product with a current verified offer has been confirmed, so no product link is shown.

Breeding

Similis is a shell brooder. The female lays eggs inside a snail shell and guards and fans the clutch; the male does not take part in later brood care. Seriously Fish reports that fry become free-swimming after about six to seven days. Breeding may occur in a well-set-up colony, though other fish can eat the young. For a dedicated breeding setup the source gives pH around 8.0–8.5 and 25–26.5 °C. These are breeding conditions, not replacements for the routine care range. Provide enough shells and condition the fish with varied live and frozen foods.

Sources & review

This care guide draws on several specialist sources and was last checked on 17 October 2026.

View the sources