General Directions!

Generally, I tend to match fin types, the same, with different body types or the body types, the same, with different fin types.

This way, you aren't likely to get some fish so rare, that it can't grow old enough to breed before it dies, or can be identified. You must research environment, and it takes a lot of your sales dollars when you are trying to get started!

Also rare fish consume the better types of food, which is not free, like your starter supplies.