Chris,

The fish that will overwinter in the pond that I have are Comets, Sarasa Comets, Shubunkins, Gold Orfee and Channel Cats. There are more but, just my inventory.

-Mike

We've got shiners and sunnies in with our goldfish and 1 koi. All have overwintered for two seasons now.

We put in some mosquito fish in the middle of the summer. Man we had a bunch at the end.
At first I thought I didnt need them because of all my circulation and my powerfull falls.
But my water hyacynth got huge as the summer went on and mutiplied really fast. So i started really watching . And sure enough...the dense water hyacynth creates small stagnant areas between the plants in the middle of the bunch. I didnt want to take any chances. Not with West Nile

I also had a friend who had rosies that he put in his pond ( feeders)
He had a ton in september.
I can always feed stuff like that to my snapping turtles.

Mike

I like my mosquito fish a lot.

I put Rosey Reds in my pond last summer. They spawned but I don't believe the fry survived. I'm a fish person too so I wasn't all that excited about the possibilities but I've been pleasantly surprised by the Roseys. They grew a lot, ate a lot of insect larvae and are always active and easy to see. I took on a Bluegill as well and it survived the winter too.

oooh...what's a Rosey? :)
I have comets, shubunkin, koi, a channel catfish and a lionhead...but my winters are fairly mild.

Here's a web page on rosies. They are cute, but don't do well in my still water ponds, whereas the mosquito fish do (probably the lack of aeration).

Here is a link that might be useful: robyn's rosy red page

Tadfish, don't you get tired of looking at goldfish? Nothing against them, but seems like every pond has them. Not that rosey reds are so much better!!

Watergal, where do you get your mosquito fish?

I got mine from ebay, very reasonably priced and healthy. I don't remember the seller's name, but they were in the Phoenix, AZ area.

I had Rosey Reds in my small pond. They make great pond fish!!

Any of the goldfish, koi, golden orfe are standard. You can also go with any fish native to your area such as bluegills, rock bass, etc. Some others that haven't been mentioned are weather loaches. 400 gallons cannot support many larger fish, even full grown goldfish. Your best approach is a few goldfish and maybe some rosy reds. If you want interesting color, go with sarasa comets or shubunkins.

I have Comets, Sarasa Comets, Shubunkins, and Fantails. I enjoy watching Fantails the most.

Orange is a nice color if you want to spot the fish quickly. I have a mostly black fish I call "The Ghost" because its almost invisible against the pond lining.

Depending upon the Fish and Game regulations in your state you may be able to keep a variety of game fish that might make a more interesting accent to your pool. Goldfish are fine but really do not pique the interest of that large mouth bass. use the goldfish to feed the larger predators.
If you are far enough south I recommend Florida Flag Fish
Wikipedia on Flag Fish-best I can find on the spur!

as it is a vergetarian species, it needs a nice dense stand of underwater plants like stands of elodea (anachris) or anything comparable in which it can hide and breed. Pools in a sunny spot are best for it.
A fish that does well in small pools-mine are in an old deep sink-are White Cloud Mountain Minnows. These Chinese natives can handle it cooler (Robyn's White Cloud Mountain Minnow Page)
Both of these fish have breed for me. Don't know if the Flag Fish are alive anymore as their pool is overgrown!!

The only fish I would NOT recommend are any species of catfish! These monsters get big and will eat anything. And if you have submerged plants these fish can loosen the plants up as they grub around. Only for large acreage ponds!

For more info on native fishes check out NANFA. link below

Here is a link that might be useful: North American Native Fish Association

i keep giant danios, white clouds, tiger barbs, cherry barbs with my goldfish during the summer in southern california. we'll see if they survive the winter. they are much more colorful in an outdoor environment.