Lydia,

It depends on what you call Mosquito fish. If you got them at a tropical
fish store/LFS they are probably a species of Gambusia which are pretty
hardy, but will probably not stand temps in the 50's very long. If it is a
local mosquito fish that is native to the region, it will probably do fine.
Fish can surprise you, though, I had two Clown loaches outside in the pond,
about 2 inches in size, and the pond temps had dropped into the very low 60
high 50's before I had the time to drain that portion of the pond to chase
them down. The Pond is 30 plus inches deep and I had to bring the level to
about 2 inches before I could finally catch. They were still the dickens to
catch, but I got them caught and they are doing fine inside now.

So to answer you question, it yes or no depending on the species of mosquito
fish you have.

Tom L.L.
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"Lydia" wrote in message
...
The pond is 2 feet deep ~ 500gal. I put about 15-20 mosquito fish in it
this fall. It's a new pond so I don't have anything else in it yet.

Usually our low temps. this season in Seattle are around 40-45F degrees,
but
we've been having cold snaps where the pond has had a layer of ice on it
for
a few days at a time during about 3 different weeks since October. One of
those weeks is this week. Overnight temps are mid 20's. Ice on the top
of
the pond again.

The feeling I get from what I read is that the mosquito fish will still be
there in the spring. Really? Honestly? Is that true? It just seems so
amazing to me that I can believe it.

Or are they most likely all dead by now? Should I do something for them
like dump hot water in or break a hole in the ice even though it'll
probably
be gone in no more than a week?

Thanks!
Lydia