This blog post explains it very well.
http://fishingsuperstarsplayersguide.blogspot.com/2012/10/aquarium-fishes-stars.html#links
My friends list is full but only about 10 of my friends actually have star worthy fish in their aquarium. I would like to exchange the non star friends for star friends. Please only post if you have star worthy fish in your aquarium.
Nosoupfo level 33 currently have only 3 star fish in aquarium. Occasionally, will have a quest fish growing. Daily player, gifts daily, will feed at least one of your fish. (Obviously, I will be fishing for your star fish eggs with the other 4 energy) Happy fishing!