I have heard that rumor myself but it is still only that a rumor something that has been discussed by Gaia's Staff but not yet in practice. Lite Fish are basically only good to have if you plan on being an alcamist from my understanding. They do do not serve any other purpose than that.
Mini Monsters are a better deal to have on hand. I am going to be releasing a page that another guild member made that will help with figuring out what fish are great to have and which ones are not that great to have. Hopefully the chart will help you figure out what fish you can afford and not afford that are good for tanks and not good. Like I said it will be today or tomorrow that I get it out there for you guys to browse through. Trying to get the newsletter and new contest ready to be released today and tomorrow.