Engraulicypris sardella

Engraulicypris sardella, commonly called the Usipa or Lake Sardine, is an endemic cyprinid of Lake Malawi and the Shire River system in East Africa. It is a small, compressed, laterally silvery fish that forms enormous pelagic schools in the open water of the lake, where it is ecologically important as a prey species for cichlids and other predators. In the aquarium it presents an unusual challenge: it is highly specialised for open-water schooling and requires alkaline, hard water that replicates Lake Malawi's chemistry. Tanks must be large — 150 L or more — with minimal decor and maximum open swimming volume. It is entirely peaceful and poses no threat to tankmates. Diet consists of small planktonic foods. Though rarely available, it is an interesting novelty for Malawi biotope enthusiasts.