Understand.
Something that might add to the fun and still provide some sort of understanding is to keep a record of Species, length and weight. If nothing else you are establishing a baseline of sorts so when/if you add other species you should see a change in number, body condition and maybe even size-eventually-in the existing species. Make it fun in that aspect and you may well end up with data that shows a trend. Granted it will be slow but you quite possibly will see changes-maybe subtle- that I think you will find interesting when you keep what you can on paper. That in itself can add enjoyment just to see what changes do happen.
Good luck!
