There are actually a number of spiney eels endemic to Lake Tanganykia, but only a few are usually collected/imported. Most of the larger species are predatory, and grow too large for the average hobbyist. Some of the smaller ones are occaisonally imported but not ID'd by species, and there isn't much (if any) info available on them. I have heard from a couple folks that the smaller odd ones tend to stay buried in the sand, much like their Asian relatives, and aren't particularly social. The elipsifer is a social fish, and can be kept in groups w/out problems. Plagiostoma are best kept alone or as a pair, though they won't kill other conspecifics like most species will in the long run.