I have read. Not actually tested, but read that colder water fish are better for this. I have also read that salt/marine or even brackish water are an option. How you would do this in AP is beyond my skill level. However, please note that this is what I have read...not actually tried.

Different types of critters in my system have their pros and cons, more of an aquaculture salad than going all one way with one species. This gives me a selection of flavors, textures and applications. So in effect if one is lower in a given area, the idea is that another will make it up.
My logic may be off, but so far so good.

I do know a lot has to do with diet, and water quality. I get surprisingly different results with growth and such by minor adjustments in diet.