A new study on the radiation of electric fish has suggested that one possible cause of new species is the ability to communicate in a different way.
The study which was undertaken by a group of scientists from around the world focussed on the elephant fish – Paramormyrops.
Elephant fish, whilst distinguished by their proboscis, are otherwise fairly bland fish with little to differentiate between species.
Whilst much work has been done on the evolution of new species due to different ecological niches or a lack of predators-as seen with Darwin’s finches, Rift Valley cichlids and Caribbean anole lizards - little is known about why some species diversify with no ecological differences. However, over 20 different species of elephant fish are known to be found in a single location of the Invindo basin in west- Central Africa.
The new study, led by Matthew Arnegard of the University of British Columbia, suggests that it may be sexual selection of the electrical signals which the fish use as communication that may cause them to diverge.
The signals, known as Electric Organ discharges (EOD) are also used to navigate and to find prey in their murky habitat but it is their part in courtship displays that is thought to be why these fish have evolved into so many similar looking species.
So different populations of fish develop slightly different signals which eventually mean they become reproductively isolated from other populations in their range.
This is similar to the diversification seen in which the Tungara frog from Brazil .