What kind of life can a 50 gal pond support?

I have a 600+ gallon raised structure made of stone block I was thinking
of making into a pond, but decided instead to get a 50 gallon rubbermaid
type insert for the structure since I wasn't sure the block structure
was sound enough to hold the weight of all that water. My question is,
Is it possible to maintain any type of animal life in that size pond?
The pond will have a 170 gal/hour pump and filter attached to a
"spitter" type of ornamental fish as a water feature.

Anyone have any luck with such a small pond and maintaining animal life
in it? This is zone 7b. Thanks for your help.
jo