Is my goldfish male or female?

I’ve had Sir Rodney for over two years now. I’ve always assumed he was a male, but how can I tell?
I hope I don’t have to change his name to Madam Rodney!

Sexing goldfish:

http://www.bristol-aquarists.org.uk/goldfish/info/sexing-fs.htm

Have fun!

It seems that Sir Rodney is a girl!

She/he doesn’t have white pimples, and the vent seems to be poking out, but that’s possibly because it’s full of a never-ending stream of poop.

I’m not sure, though. It’s snowy out there, so Sir Rodney’s mating instincts might not have cut in yet.

Thanks for the response!

The site says: Put quite simply - in the breeding season, males chase after females to induce them to spawn. Easy? No. Why? Because males will chase each other in the absence of females.

Jen says: I’ve heard it goes like that in jail, too!