A bright blue variant normally referred to as ‘electric blue Jack Dempsey’ or simply ‘EBJD’ is of unclear origin but it appears to be an ornamental strain fixed from a natural mutation.

Care is as per the natural form although the blue fish tend to remain smaller and some reports suggest them to be less aggressive.

R. octofasciata has a confusing taxono…

Wild swordtails are a fairly basic green colur. However the vast majority of swordtails available in the hobby today are hybrids of X.helleri with X.maculatus or X.variatus. There are a huge number of selectively-bred varieties available, including wagtail, lyretail, tuxedo, albino, neon, red, green and hi-fin.

Swordtails may undergo what appears to be a change in sex. In young fish this may simply be late development. However some adult females develop male characteristics which is thought …