you need an anatomical list of the parts of fish?
the functions of the tilapia fish in general has been for weed control in lakes and ponds.
I got that info out of the book- NATIONAL AUDUBON SOCIETY , FIELD GUIDE TO NORTH AMERICAN FISHES, WHALES, AND DOLPHINS.
they have detailed fish anatomy- you should be able to find what you need there.
Tilapia have the same basic structure as other fish ... these two pages combined should give you everything you need: