Not necessarily as ChrisK said. My largest male rusty has 4 egg spots, the other male has 3 and both female rusties have one egg spot each. That doesn't warrant that the ones you have with one spot are females and that the rest are males. You will have to wait and continue to watch their behavior (but some females are dominant too) and their change in color as they mature. My males have a rusty-violet sheen and my females are more plain rusty or brownish. But remember that the most reliable way to sex cichlids is by venting.