Hi Jason,
You wrote:
"One other question-I have heard that many of the Tilapia you can buy out there as fry or very small are actually sterile, and you can not make breeding pairs out of them...is this true?"
It does not appear anyone has responded to this question, so I will give it a go. We could probably make this an on-going blog topic, but I am not involved in management issues and am about as new to this blog as you.
I have raised Tilapia successfully from breeders to fry in years past as an aquarium enthusiast. I have determined from extensive reading on the "internet"s that interbreeding different species of the Tilapia will indeed result in sterile offspring. The reason for these cross breeds offered for sale is that they have "hybrid vigor" and are therefore larger, process more plant nutrient materials and yield larger fish in the long run - but the hybrids are sterile! ... and probably a few more reasons for using them not mentioned yet.
From what I have gathered, here and elsewhere: if you want breeding pairs you have to bite the bullet and pay for whatever pure breed pair or hybrid pair (from pure breed parents) that you feel you can afford. I am pretty sure you have figured this out on your own by now but I still think this site should spell it out somewhere.
I think there are a so many particular questions to the Tilapia! There could be an entire blog site just for that genus and their biology. Just yesterday I was buying dog food at the feed store and almost bought the Cichlid book but there was nothing on Tilapia at all. This is a very specific topic and your question is more than excellent.
Hope this is helpful to you and anybody else that comes along.
Best, Scottco