Shell Dwellers For Small Tanks

By LittleMousling
 
5 gallons:
 
Neolamprologus brevis is a species uniquely suited to small tanks, far more so than many of the active schooling fish (white clouds, neons, or, worst of all, danios) that are more frequently recommended for them. Brevis pairs maintain such tiny territories that a pair, alone in a 5 gallon tank, may not even venture into the far corner - for the entire period of time they live in the tank! The pair is much more preoccupied with guarding a territory, flirting, and raising fry to be swimming all over.
 
The variety of brevis (which may turn out to be a separate species) known as "Minuta" is an even better choice since it stays at most half the size of normal brevis; there are size differences between the more common varieties as well but those are comparatively minor.
 
It should be noted that groups of brevis, bachelors, and a male and a female who aren't breeding do not make half as good choices for a five gallon – more willing to explore and less tied to a territory, they lead much more peregrinating lives. A couple of bachelor brevis in my 6' tank managed to use about a quarter of it, the front lefthand corner, which isn't much but is certainly more than a five gallon would have afforded them. On the other hand, a single brevis makes a "pet" fish as interesting as an oscar, if more retiring, for the smaller tank.
 
10 gallons and (slightly) smaller:
 
A ten gallon tank allows for a much greater variety of species. If you can find them, a pair of ornatippinis, speciosus, kungweensis, or signatus pair will do very well; the more common species are discussed below.
 
Neolamprologus multifasciatus is a common recommendation for the small tank, and for good reason; their colonial, easy-going lifestyle is a great complement to a small space, and the diminutive adult size doesn't hurt either. As many as a male and four females will be absolutely fine in a ten, but since they reproduce so prolifically, a trio might be a better place to start.
 
Neolamprologus similis is closely related to multifasciatus and shares its colony lifestyle, but with a caveat. In a smaller tank (ie, the scope of this article) they just won't do well in groups. A pair is the safest stocking plan for them, although in certain cases trios may work. Fry will be tolerated very well for a significant period of time but will eventually need to be removed.
 
Lamprologus ocellatus is one of the most popular shelldwellers because it's by far the most colorful; the oft-seen gold form is not only bright yellow but has a lavender sheen. However, it is also one of the most aggressive shellies, happy to drive tankmates into the corners and starve them out. A pair will do well in a 10 gallon but only an actual pair—two males, two females, or a couple who won't breed will probably just endanger each other, especially once they start to get to greater sizes – this species passes 2", although most females won't make it to that size.
 
Lamprologus meleagris/stappersi is another fish I think is actually best off in a smaller tank. Stressed half to death at the drop of a hat or a danio, they really deserve a species tank in which to flourish. Another aggressive species, a slightly larger tank will afford better chances for harems, but for a pair a ten is just about the perfect size—each fish can stake out an acceptable territory, but they won't be so spread out they manage to avoid each other completely. With this species and the ocellatus above, a nice feature is the ability to decorate somewhat more heavily, since they only need a handful of well-spaced shells.
 
Conclusion:
 
The downsides with keeping any shelldweller in a small tank are fairly obvious. A tight hold of water quality is required; weekly water changes are a good place to start, and don't neglect the filter. Fry will need to be removed sooner rather than later. Aggression between fish can escalate much more quickly. Floor space is limited and so decoration needs to be fairly Spartan; for the species that love a thick shellbed, particularly multifasciatus it's best to fill the tank with shells, shells, shells and leave the other ornaments out. The urge to find tankmates should be curbed when dealing with small tanks; even the easy-going brevis may soon find a reason to harass tankmates when forced to live in close quarters with them.
 
On the whole, though, there simply are no better desktop fish than shelldwellers – unless, of course, you need to focus on your work!