Can you Determine Sexes from Aggression signs?

[2_Basic]

Is it possible to determine female/male ratio by watching who chases who around most often?

If so... I got one for you... lol :)

I have 7 discus in 75g.

1 pigeon male (paired with female which died)
1 red melon female guy told me so
5 others 1 brown & blues for simplicity

The red melon chases the brown and the biggest blue around ALOT (these 3 are biggest sizes in tank)...and all other blues less.

Everyone else attacks chases each other.

the only 2 that seem to never battle are the ..Pigeon male & Red Melon Female.

I'm getting a bigger tank and was wondering if I should get more of 1 sex to lessen aggression.

[DISCUS STU]

It's hard to tell the sexes by their aggression. I've seen very aggressive females and very passive males. No way to tell this way.

[John_Nicholson]

The meanest fish I ever owned was a very small female.

-john

[nc0gnet0]

Sometimes, but it is far from conclusive. For instance I have a few proven males that when introduced to a female will begin to bow and dance almost immediately. When the same male is introduced to a female, they will become very aggressive. However, you need a proven male or two to do this, and even then I would not consider it conclusive until you have had enough time to know that particular proven male and his habits.

[DISCUS STU]

Thought it's not the case for all males, one way to determine sex is with the "Streamers" that some males develop on the back edge of their dorsal fins. As far as I know females don't develop these. I have one male that has one and it's become much more elongated, all in one day, now that it's paired off and has fertilized his first batch of eggs. That was new to me. Here's a pic. of one, though they can get much longer and almost look like flags or banners sometimes, hence "Streamers". I'd like to breed this one but so far he's not fertilizing the eggs. He was originally bred from a spotted Red Turquoise male and a Snakeskin mother. By the way the female snakeskin can be very aggressive, the male almost no aggression. 83272

[John_Nicholson]

Sorry but females can have streamers also. Most call them trailers.

-john

[DISCUS STU]

New to me, I haven't seen it yet, but I'm sure there's a lot of other experiences out there.

[Larry Bugg]

I have had females with trailers also.

[aquadon2222]

The meanest fish I ever owned was a very small female.

-john

whoa, john and I actually agree on something! ;-)....while the bigger males too be the dominant fish, it's not a hard rule at all - I've had small fish be the top of the pecking order, I've seen females, I've even seen small females run the roost.