what coldwater animals can i have in a tank?

Alice Asked: what coldwater animals can i have in a tank?

I have a 22 pint(Don't know what it is in gallons UK) Fish tank and I was going to add animals to it but i don't know any animal that can go in a cold water fish tank, I know there is some types of small shrimp but I don't know what they are called.

I have already got a red cap oranda fish(YES,the tank is to small, whatever!) I was going to give her to someone for free but no one wants here:( so I am stuck with her, he is fine, healthy, I have got a fish specialist book that i Brought about health and i check her health everyday and she is FINE.
I got a internal filter, a barrel rock thing(decoration), got LIVE plants.

SO can i have some name of cold water animal that are not hard to look after! i heard about cherry shrimps?
name types?

THANKS!

P.S people that have no patience your wasting your time!