sexing by fins?

[Dave+Amy]

Hey,
I'm not into the breeding scene but I'm selling a Discus at the moment and some potential buyers want an indication of sex, I have no idea how to sex Discus - it hasn't paired off with any other Discus and no spawning.
It's 10cm...fully grown, was brought stunted :roll: little did I know..

Is it true that you can sex a Discus by looking at the fins and tail? if so - how does that method work, what should I look at to give me an indication of sex?

Any advice would be appreciated :)

[iro11a]

I heard that female discus top fish is more circled and the male goes around but drops down a little then continues a curve

[Merrilyn]

Generally, and I do mean generally, male discus will have a more pointed end to the dorsal fin and anal fin, while the female has a more rounded fin.

It's certainly not foolproof, and I had a gorgeous big bulky blue diamond, that I was convinced was a male, long streamer to the dorsal fin and everything, until it LAID EGGS !!!!! :roll:

Just when you think you know it all, a discus will come along and drag you down to earth again :?

[Dave+Amy]

lol yeah I guess it's just a rough estimate..also it is very aggressive to the others would that make it more likely a male?

[ILLUSN]

if you look at blue discus often the male will develop a spur or stramer fron their top fin or sometimes even the tail, these are much rarer in female discus.

[Merrilyn]

lol yeah I guess it's just a rough estimate..also it is very aggressive to the others would that make it more likely a male?

Females usually choose the nesting area, so if it appears to be keeping the rest of the fish away from a certain area, with or without a mate, it's more likely to be female.

[Dave+Amy]

thanks for that :D will pass it on when the guy comes to pick it up

[AHC]

In addition to the rounded female fin vs the less rounded male fin - From what ive seen and read, If you follow the fin line down towards the tail fin and the line intersects the tail fin then its more likely female. If the fin line cross the tail fin just past the end of the fin then its more likely male. Hope that makes sense.

There is also a bigger gap near the bum, tubes for females.

[Dave+Amy]

Wow that's an amazing drawing :) has this method worked for anyone all the time?

[AHC]

Why thank you :roll:. No method is 100%. It has been a good guide for me and my experiences. There is some info somewhere from some German guys (i think) that wrote a piece on sexing Discus based on geometry which is where i originally found that info. See other people's thoughts and keep that piece of info with you when you look at discus in the future. Oh and you will never identify a young discus. Only adults (sub adults too but it can be hard).

[Dave+Amy]

Oh right...so no point in using this on Discus under a year old then? I can't tell the difference in breeding tubes when I had a look at a post on the forum..the distance you refer to infront of the anus about how female have larger distances - is the distance the one between the pelvic fins and the anus?

[AHC]

Yep, thats it. Just before females lay eggs that tube will also extend out a little. All these things combined should give you an idea on what sex they are and practice / experience is the key to a good guestimate. It is hard to pick.

[Dave+Amy]

awesome thanks for that!