Originally posted by Fur&Feathers
Correct me if I'm wrong... but aren't those females ?
Nope, they are males. They are called "Plakats." They resemble the type of Betta that reside in the wild.
Here's a better description quoted from fishforums.net:

Plakats are the natural form of Betta splendens, the type occuring in the wild. The short fins allow for the fish to get around quickly, without any excess finnage weighing them down. Any other tail type is a man-made mutation. In the Plakat male, the anal fin is markedly extended and pointed, when compared with females. The tail is symmetrical, and the rays branch at least once.