What species of goldfish that stays active in cold water while others are in torpor?

[Jeff G]

I have a 3 year old, Zone 6b, 1000 gallon pond in the woods that I have stocked with feeder fish from the local fish store. (I call them rescue fish. Each spring I have been adding a dozen so there is a range of sizes. They all get along fine.
There are now:
7 "old" ones about 6 inches,
9 midsize about 4"
9 of the yoogether ungest about 3".
I have thermometers around and in the pond so I know temperature well

Here's my question.
I went out to the pond today in 36F weather and saw that all but one of the fish are down at the bottom in torpor state. One fish was grazing very actively at the surface! It was able to dart away when I used my net to take out leaves and litter. The active gold fish is midsized and looks a little longer and sleeker than the others. The water is 41F near the top[ surface and 37F about a foot down. He was moving very actively in that zone while the others were grouped together 3-4 ft down "torporing"
Is this fish an anomaly? Are there breeds of goldfish that are active at lower temperatures? If there are I'd like to get more.

Thanks for your help. I learn a lot from all of you.

 

[sissy]

Mine have been active but I think they are wondering what the new green thing is floating in the pond .I have not checked the water temp.

 

[Faebinder]

Technically all the goldfish species can survive under ice.... the ones least likely to have problems are the shubunkins, commons and comets.

 

[Lisak1]

I don't think the OP was referring to surviving - it seems @Jeff G has one fish that REALLY LIKES the cold water!

Maybe a golden Orfe? I know they are really cold hardy, and they tend to be long and slender fish - does it have a dark spot on it's head? Can you share a picture perhaps?

 

[MitchM]

Sometimes fish will stay in areas of warmer water for a while and their body temperature will rise as a result.
They'll remain more active until their body temperature drops again when they enter a cooler water temperature area.

 

[MoonShadows]

Even when my pond water got down to the low thirties during that last round of severe cold, my sarassa comets still seemed pretty active to me.

 

[Faebinder]

I keep multiple types of goldfish in my pond... There is a lot of variability in their behavior during the winter. Younger fish are generally more active. Fancy goldfish are more likely to be inactive.

 

[addy1]

Until the ice got to thick to see through I was watching the fish swim around under it. Not a lot of them but every now and then one would go by.