I have 5 julidochromis, and i'v been reading up about sexing, and venting them. I'v also read that the female is usually the larger one. The largest juli in my tank is about 4.5 inches, and has a verry obvious "thing" next to it's anus. The problem is that all my julies seem to have a "thing" of various size. Do the females also have something? or maybe I'm stuck with all males? Is there any other tell tale signs?