Electric fish or mormyrids are fish found in Africa that emit a weak electrical pulse to communicate with other fish. Different electrical signatures from the fish indicate different meanings such as aggression and courtship.
Recently, the electrical signals of two groups of the same species of the electric fish were measured, and each group had a different courtship signature. Researchers interpret this could be the first step in speciation; that is, one species becoming two species. This would be an example of sympatric speciation, although further data could falsify this claim.