The EODs of the mormyrid fishes shown here are all from the Ivindo River and surrounding streams of North-Eastern Gabon. Each species has a species-typical EOD waveform which is illustrated by one or two example traces.
For many of these species, male and female EODs differ. Male EODs are usually longer in duration than female or juvenile EODs, but the shape of the EOD may also be quite different.
For many of the mormyrids shown here, the EOD is species-specific within this geographical region.
Here is a map of the biogeographical region where these studies have been done. Gabon (left) straddles the equator on the west coast of central Africa. The main drainage is the Ogooué River, which drains to the Atlantic through a series of freshwater lakes and swamps. The Ivindo River, a tributary in the north-east of Gabon has a number of unusual species of fish that are known only from this biogeographical area.