Sexing pangasias catfish

[daisycat]

Anyone know how to sex pangasias catfish? We have two and they play together and nuzzle noses and stuff and I wondered what sex they are. They look pretty similar in body shape but one is more greyblue and the other is more silvergrey.

PS. If you could spare me the lectures about potential size of these fish I would appreciate it, I have heard it all before!

 

[CFC]

There are no external differences and the fish has never been spawned in captivity without the aid of hormone injections.


BTW do you know how big they get?

 

[daisycat]

thanks CFC, I have an inkling about their potential size!

I wasn't thinking in terms of breeding them or anything (where would I find tanks to house all the babies?!), just being interested really...