Fish and other Creatures in your Aquaponics

Who or what lives in your aquaponic system ?
I have white Tilapia living in
tanks that drain into my vegetable troughs.  BUT  they are not the only creatures in
the system.

 Who else lurks  there under the vegetables? It probably depends
on where you live.

Here in Hawai :
Red worms magically appear after 6 months or so . Later a small shrimp that
cleans the roots of the plants appeared. These are both good guys that you want in your system.
The red worms and the small shrimp (gammarus) live on the bottom of our system as well as in the roots of the plants.

Pests occasionally found in the system include slugs , snails, and once even a centipede.

There are other creatures that you can add to your system too.
Prawns like to live in your troughs
under the plants.  They are very tasty but on the down side, they fight and kill each other
and even crawl out of the system at times.
Catfish can also live under your plants and if fed won't do too much damage to your plant roots since they are bottom feeders.