Moromyridae

Moromyridae is a family of fish which includes the Aba and elephant nose fishes. These fish a very large brain compared with their body weight. This is mostly due to their large cerebellum. This large cerebellum controls the use of their electrcal discharging organs, which produces electric fields and may be used for detection of other fish as well as communicating with other fish. Thus, to control and process all the electrical information the cerebellum of the fish has expanded and gotten larger. Another interesting characteristic of Moromydridae is that their swim bladder extends into their braincase and the addition of a bony rod which supports their caudual peduncle. These structures help maintain a rigid bent shape to the fish. This ridgid shape is necessary due to their organs which produce an electric field. If they were to move, even a tiny bit, their electrical field would be disrupted, and thus they must maintain a ridgid shape. As a result these fish largely move by sending sin waves down their dorsal fin, producing as little change in their shape as possible.