Setting Up a Colony Tank for Shell-Dwelling Cichlids (Multifasciatus & Similis)

Shell-dwelling cichlids are some of the smallest fish in the whole Lake Tanganyika hobby, and they need a setup that looks almost nothing like a typical cichlid tank. No rockwork towers, no wide-open swimming space, no single dominant pair claiming the whole aquarium. Get a colony tank for species like Neolamprologus multifasciatus or N. similis right, and you end up with one of the most genuinely entertaining setups in the hobby — a whole miniature society playing out over a few square feet of sand.

Both species spend essentially their entire lives in and around empty snail shells sitting on open sand. Multifasciatus is the smaller and bolder of the two, often called the world's smallest known cichlid, and it's constantly visible — darting between shells, digging, defending territory against neighbours barely bigger than itself. Similis is a close relative with the same lifestyle but a shyer temperament, doing best in slightly larger numbers so there's always another shell-dweller nearby for confidence.

Substrate is the first thing to get right, and it's not optional the way it might be for a rockwork community tank. You want fine sand, at least 3 to 5cm deep, so the colony can actually dig and rearrange shells the way they would in the lake. Coarse gravel doesn't let them dig properly and defeats a lot of their natural behaviour before the tank's even stocked.

Shells are the other non-negotiable. Real empty snail shells work best — escargot shells from a food-safe source are the common choice, since they're the right size and won't leach anything harmful once cleaned. As a rough starting point, aim for two to three shells per fish so there's always a spare for a fish that gets pushed out of its current one, plus room for the colony to expand as they breed. Ceramic shell-alternatives exist and work fine too, but real shells are cheap, look natural, and are what most established colonies are already used to.

Stocking density is where shell-dweller colonies really differ from other cichlids. Rather than one pair per tank, you're aiming for an actual colony — six or more individuals is a realistic starting point for multifasciatus in anything from about 60L up, since the whole point is the constant low-level social interaction between neighbours. Too few fish in too much open sand and you lose the busy, layered colony behaviour that makes this style of tank worth doing in the first place.

Tankmates need real thought. Shell-dwellers are tiny, and almost anything sharing the tank with them — even other peaceful Tanganyikans — can end up intimidating or outcompeting them for food. A dedicated species tank, or at most a very carefully chosen peaceful sand-dweller sharing the same water column preferences, is the safer call than trying to fold a shell-dweller colony into a general community setup.

Water chemistry follows the same hard, alkaline rules as every other Lake Tanganyika species — see our tank setup guide if you haven't sorted that out yet, since it matters just as much here as for any rockwork-dwelling Tanganyikan.

If you're ready to start a colony, we currently breed both Multis and Similis here in Sydney — full care details and current availability are on each species' own page, and our Species Care Guide has tank size and water parameters for everything else we keep if you're planning tankmates.