not realy, if you keep 2 or more fish that use electroreception together theres a chance that they will fight.in the lfs you will see them kept together but as they mature they will become intollerant of others of the same species unless you have a male and a female(with apterontidea the males electric organ discharge is greater than males or females but with other gymnotiforms and mormyriforms the female has the greater e.o.d)but even then i would sugest keeping them seperate most of the year untill you want to breed, specialy if you have a proven pair.