How can I tell a Butterfly Koi from a Shubunkin?

[Algernon]

In my backyard outdoor pond I have a mix of Koi and Shubunkin and Comets.

Two of my fish, sold to me as Butterfly Koi, look to me more like Shubunkin in coloration. Is there a way to tell by appearance? As I look at the ones I know for sure, the Koi scales seem to be more apparent than the Shubunkin scales (it’s hard to even see the scales on the Shubunkin at all – if I didn’t know better I’d claim they were a scaleless fish.).

The fish were purchased a couple years ago. At the time they looked like Koi, but now with the changes in coloration over time they look different.

It really doesn’t matter I guess. But I’m curious and I’d like to be correct when describing the fish to others.

[carnivorousplant]

Google image both and check them out.
The butterfly has longer pectoral fins. Koi have I believe large color patches than shubunkins.

If you have shubunkins and comets, pretty soon you will have some plain goldfish-they will spawn haphazardly.

[DrFidelius]

Koi have barbles, even the “butterfly” koi.

Shubunkins and other “goldfish” are a different variety of carp, and do not have barbles.

[Apricot]

As DrFidelius says, by the whiskers. Koi and Goldfish sometimes interbreed, but the babies, no matter how koi-like, will not have whiskers.

[carnivorousplant]

@Apricot

Koi and Goldfish sometimes interbreed,

My I ask you for a cite in a friendly manner?

[Apricot]

Sure~! Will wiki do?

Koi may also interbreed to produce a sterile new fish.

Goldfish

also

Do Goldfish and Koi Interbreed? The answer is yes but the offspring aren’t what you would call show quality. In fact, they are not the prettiest of fish and thank goodness they are sterile.

http://www.ponddoc.com/WhatsUpDoc/FishBehavior/ThatsAmore.html

[carnivorousplant]

Thanks, Apricot.

[Algernon]

Nice work Dopers. OK, let’s see. Pectoral fins longer on Butterfly Koi? Hmmm. Given that the fish are different sizes it might be a bit difficult to tell.

Barbels? The fish I was questioning certainly has barbels. I guess that’s the simplest test.

(though I could’ve sworn the Shubunkin had barbels too – time to head to the pond with my binoculars)

By the way, all this talk of breeding and cross-breeding. I have never had more than two or three babies each year for the last five years. This summer I have somewhere between 25-35 babies. Too early to tell what they are, but I have a large range of coloration. I may have reached the population limits of my ~2000 gallon pond. Ah well. They all won’t survive the winter anyway.

Thanks for your help.

[carnivorousplant]

@Algernon

Nice work Dopers. OK, let’s see. Pectoral fins longer on Butterfly Koi? Hmmm. Given that the fish are different sizes it might be a bit difficult to tell.

Barbels? The fish I was questioning certainly has barbels. I guess that’s the simplest test.

They all won’t survive the winter anyway.

Proportionately longer fins. That’s where they get the “Butterfly”.
Go with the barbels for species ID.
Survival depends upon where you are. Goldfish can live under ice.
Koi supposedly cannot. One aquarium write in Maine brings his Koi to an indoor pool in Winter. One Doper leaves them under ice and they make it.

[Algernon]

@carnivorousplant

Survival depends upon where you are. Goldfish can live under ice. Koi supposedly cannot.

I’ve had a pretty good success rate* with a heater and aerator and a small pump to keep about a 4 foot “square” opening in the ice. Even so, I lose a few over the winter – Koi usually, since they are more fragile than either the Comets or Shubunkin.

*except for my very first winter where the electricity went out and the pond froze over for a few days. It was enough to kill every fish in the pond.