help identifying male Vs. Female

[ouiouigirl]

Hi you all,

well while I did enjoy my heavily planted freshwater tank, the fish bore me to tears not the mention the algae growth despite a 75w setting. So I went back to my old time favorites, the full of life and perky african cichlids. Bought 6 the other day at the LFS after setting up the tank with a mix of my former freshwater gravel and argonite, got lots of rocks in the background for caves and other hideouts. As usual the LFS dude had no idea how to differenciate male and females so I did my best with the left over knowledge I had from way back then....I need help though. I have 3 yellow labs and 3 electric blue (excuse me while I don't use the latin names). Here are a few pix, any help greatly appreciated.
Thank you all for the help.

[clayt101]

Well, not being an expert on yellow labs, one thing I notice is that males usually have more black on their bottom fin then females. In addition, they may have an egg spot or two. So, that being said, I say 3 female yellow labs, but you really have to look at them much more closely for anything definitive.

[ouiouigirl]

thanks, one of them, the largest one has more black on its fins I think it might be a male and two females, as for teh blues, unfortunately I think they're all males, what do you think?