Similis Shell Dweller (Neolamprologus similis)

Common Name

Similis Shell Dweller
Neolamprologus similis

Neolamprologus similis is a small Lake Tanganyika shell dwelling cichlid that thrives in colonies, with each fish claiming a snail shell as home base. It is best appreciated in a species focused setup where their digging behavior and social interactions can take center stage.

Origin and Habitat

This species is endemic to Lake Tanganyika in East Africa, with records from the Democratic Republic of the Congo and Tanzania.

In the wild it inhabits sandy areas where empty gastropod shells accumulate, using shells as both refuge and breeding sites. These are typically clear, highly mineralized, alkaline waters with gentle water movement along the lake floor, and the habitat is defined more by sand, shells, and nearby rock structure than by heavy plant growth.

Biotope notes. A Tanganyika shell bed inspired aquarium is mostly fine sand plus a dense cluster of shells, with optional rock piles at the edges to create sight breaks. In nature, shell breeders use empty shells from large gastropods such as Neothauma tanganyicense, and shell beds may include other shells mentioned in the scientific literature. A true shell bed look is often plant free, but if you want greenery in an alkaline, hard water system, keep hardy rooted plants to the perimeter so the colony still has open sand to excavate.

Temperature and Water Conditions

Aim for 24 to 27 °C, which is about 75 to 81 °F, with steady temperature and strong biological filtration. A broader range of about 23 to 28 °C is commonly reported for the species.

Wild pH values are commonly reported in the alkaline range, around 7.4 to 8.4. We do not recommend chasing or altering water parameters except in special breeding situations. Stable conditions are far more important.

Hardness and mineral content should be on the higher side, since Tanganyika shell breeders are adapted to mineral rich water. Regardless of your exact numbers, keep ammonia and nitrite at zero, keep nitrate low, and avoid sudden swings from large, infrequent water changes.

Appearance and Size

Similis Shell Dwellers have a compact lamprologine shape with crisp vertical barring across a sandy tan to brown base. Subtle pale or blue highlights can show in the fins and around the face under good light.

Maximum adult length is about 5 cm, which is about 2.0 inches. Sexes are similar in pattern, but males are typically a bit larger and may show slightly fuller finnage, while females stay smaller and are often seen deeper in the shell during spawning and early fry care.

Diet in the Wild

In Lake Tanganyika, shell dwelling lamprologines feed opportunistically on small invertebrates and edible bits drifting past their territory, plus items picked from sand and nearby surfaces. Reported stomach contents include small crustaceans such as copepods and ostracods, insect larvae, and filamentous algae strands.

Molecular diet work on Lake Tanganyika cichlids also supports the idea that many species have broader and more variable invertebrate driven diets than older visual stomach content surveys alone can capture, depending on microhabitat and season.

Feeding in Captivity

Feed like a small Tanganyikan predator that does best on variety and consistency. Use a high quality small pellet or granule as the staple, once or twice daily depending on temperature and stocking.

Add frozen foods like cyclops, baby brine shrimp, and finely chopped mysis several times per week for conditioning and breeding fuel. Keep portions modest, since overfeeding will quickly degrade water quality in a dense colony. When conditioning breeders, slightly increase protein rich frozen feeds while keeping water changes frequent and steady.

Behavior and Tank Setup

This is a colony former with strong shell based territorial behavior. The most natural way to keep them is as a group, letting them self organize around a shell field. In mixed sex groups, one male often holds a loose territory over multiple nearby females, with frequent low level boundary checks between neighbors.

Minimum tank size. For a starter colony, a 20 gallon long, about 76 L, is a comfortable footprint because floor space matters more than height. For larger colonies or if you want multiple male territories, a 30 to 40 gallon breeder style footprint is even better.

Aquascape and equipment. Use fine sand so they can dig and reposition shells. Provide more shells than fish so subdominant individuals can claim space without constant conflict. Keep filtration efficient but not blasting, and prioritize oxygenation and stability. A tight fitting lid is recommended, especially if you run strong surface agitation.

Tank mates. If your goal is fry production and full behavior, a species tank is best. If you want companions, choose calm Tanganyika fish that occupy different zones and will not hunt fry. Many tank mates will opportunistically eat fry when they venture out.

Breeding

This is a shell spawning substrate breeder. The female deposits eggs inside a chosen shell and remains in the shell to guard and tend the brood, while the male defends the surrounding territory and fertilizes at the shell entrance.

In aquariums, eggs often hatch in about 24 hours, and fry become free swimming at roughly 6 to 7 days, depending on temperature. The biggest triggers are stability, abundant shells, frequent small water changes, and consistent feeding.

Protective structures that improve survival are simple: lots of intact shells with varied openings, plus a few rock piles at the edges to break lines of sight and reduce constant chasing. Research on a closely related shell dwelling species shows strong preferences for intact shells and for certain structural features, which matches what aquarists see when providing a mixed selection of shells.

Breeder’s Tips

• Start with a group so pairs form naturally
• Offer extra shells, at least one per fish and preferably more
• Feed small portions twice daily, then add frozen cyclops or baby brine for conditioning
• Keep water changes frequent and gentle to avoid disrupting the shell field
• First foods for fry include powdered fry foods, rotifers, and newly hatched brine shrimp once they are taking larger prey

Quick Facts

• Scientific name: Neolamprologus similis
• Common name: Similis Shell Dweller
• Origin: Lake Tanganyika, Democratic Republic of the Congo and Tanzania
• Adult size: Up to about 5 cm, 2.0 inches
• Temperature: About 24 to 27 °C, 75 to 81 °F
• pH: About 7.4 to 8.4 in the wild, keep stable rather than exact
• Hardness: Mineral rich water preferred, reported tolerance is broad
• Temperament: Territorial around shells, best in colonies with plenty of space
• Diet: Small invertebrates, planktonic crustaceans, insect larvae, plus some algae and biofilm picking
• Breeding: Shell spawning substrate breeder, provide abundant intact shells and fine sand

Tropical Fish Co. Notes

If you have ever wanted a Tanganyika setup that feels alive without needing a massive aquarium, this is one of the best answers. A Similis colony turns a flat sandy bottom into a busy neighborhood, with constant shell renovations and tiny, determined personalities.

The trick is resisting the urge to decorate the whole tank. Give them open sand, a real shell field, stable clean water, and let the behavior be the scape. If you are mixing, think carefully about who shares the floor. Most problems come from not enough shells, sand that is too coarse to dig, or tank mates that keep the colony pinned down.