on the mbunas, one way to tell male/female is by the spots on there lower fin near the tail. these are egg spots used for mating.... [/url]
Actually thats one of those wives tails; I've been keeping mbunas for 20 years, and have plenty of females with egg spots on the anal fin. I've seen that same information in books as well, but its not anywhere close to accurate. I'd say that close to 50% of your females, if not more, will have eggs spots.
Here's a picture of the divider wall that I created; we epoxyied sand to the foam area on this was complete. For some reason I can't find my pictures of the finished product, but you get the idea.