Sexing young Discus.

[bernie82]

It seems that whenever I aquired a colony of young Discus, 80 to 90% eventully turned out to be females. I've talked with quite a few breeders and in most cases, they agreed agree with me.
When I select young fish now from a large group I assume that the really aggressive ones are more likely to be males. It's not foolproof but It's been working for me.
If I visit someones fish room with the purpose of buying some fish to raise into breeders, I'll probably spend at least 30 to 45 minutes studying their behavior before I select the ones that I want.
How about somefeedback on this theory?

[April]

sure sounds good.
in a batch you can see some big dominant ones. you need to get some of different sizes.and does help to watch them interact.
but...im sure its still the luck of the draw in the end.
but..try my method. look deep into their eyes..look for the ones with the sweet innocent look. lol. those are the girls. ::)

[Mattzilla]

i have used your theory before bernie...ie males are more aggresive and dominating but some females can be that also....it's very hard to tell..
i also use the shape of their fins to guesstimate their sex.

but one thing is sure, i'm definately no expert!!!!

matt

[A Niner Fan]

So for sub-adults, if the tips of the anal and dorsals form a point, it's surely a male? Female is always round (er)?

[John_Nicholson]

For the most part the shape of the fins theory is full of holes. Males do normally grow larger and faster. Theproblem arises because we normally sell fish based on size. Many of the males in a spawn matbe hitting 3 inches while the females are closer to 2. Someone buys 10 3 inch fish the breeder ships 10 3 inch fish. Mostly males. A month later most of the males have been sold, but now the females are pushing 3 inches. The next customer to order 10 3 inch fish gets al,ost all females. See where I am going with this? If you want brood stock then go to the breeders and pick from a large group the biggest 4 or 5 and then pick 7 or 8 of the mid sized fish. You will get some big bull males but also plenty of good females.

-john

[bernie82]

I have found that about 90% of the time the dominant fish in the group is a male. As I said before, most spawns produce many more females than males.

[John_Nicholson]

I have never kept an entire spawn to prove this but I really do not think that the number of females is significantly higher then the numbers of males. What are you baseing this on?

-john

[bernie82]

Hi John.
I'm basing it on my 30 years of raising and breeding discus. Herman Chan, the owner of the Fairy Lake Discus palace went as far as to say "he has raised hundreds of fish from fry to breeders in his 30 plus years of experience and believes that 90% of the fry of Angels and Discus are females." Mike Misuraco, a member of Simply Discus and expert breeder of beautiful fish says "at least 80% of the fry I've raised turn out to be females.

[John_Nicholson]

So this is word of mouth? Sorry I still don't believe it. I know Herman is an exceptional breeder. I have never met Mike but I know he is a capable breeder. I don't have the room to grow out entire spawns normally but I have 2 very small spawns that I was keeping anyways so I will see what happens. In one spawn the female flipped out and went on a killing spree. I saved 11 fry from that spawn. I have another spawn from a old male that belongs to a friend of mine. He really wanted to try and get fry from him. I paired him wiht a good female but only 8 fry hatched. The raise 6 (as strange as that is). One of which is deformed and will be culled. Right now I am keeping it so the others have someone to pick on. By you statements I should have about 13 females and 3 males. They ate about 3 months old. I am willing to bet that more then 3 will be males. You game?

-john

[Rick_May]

I don't know if it's 80-90%, Id guess that 60% are females 15% never do anything, 10% are mules, and that leaves just 15% turn out to be good males. JMO

[Rod]

I disagree with the 85% + female theory on sex ratios. One time i was trying to increase size in my rt line so i kept 13 largest from a spawn of about 150, 12 of these were males and only 1 female.

In a related subject, i used to breed many fighters and the sex ratio can be controlled by ph. lower ph >6 gives more females in bettas, perhaps the discus are affected the same way although i have never grown out a whole spawn to breeding age.

Rod

[John_Nicholson]

60% females I could buy, but not 80 to 90%. It makes no sense in the evolution of the fish. Everything happens for a reason. If the females faces a higher death rate in nature then males then a 80 to 90% rate might makes sense but since both sexes care for the young and are both exposed to the same dangers.

-john

[chirohorn]

A general rule of nature is there are more females than males. The reason? Females bear the young. A male is only needed for the fertilization & can go on to the next female. ;D But the proportion isn't anywhere close to being 85/15. More like 51/49 for humans (I think).

Wanted to add that temperature is related to the sex of fry. I recall a study where eggs that were hatched in a relatively higher temp. resulted in increased males. Conversely, lower water temps produced more females.

[bernie82]

Hi John. It doesn't make sense that there would be so many more females than males. I never made a study of it. It's my gut feeling. I mentioned it to Herman and he was positive that his angels and discus produced 90% females. I thought it was only my opinion and it seemed so ridiculous that I was reluctant to even repeat it. When Herman told me his 90% opinion I checked with Mike and he said at least 80%. Never the less, the main issue here is "is the dominant junvinile fish in a tank of relatively equal sized fish most frequently a male?" What's your take on that one, John?

[John_Nicholson]

I would lean that way but it is not 100%. I have had some females that whooped everyone in the tank. Including males that were much larger. I think (just like with people) males are more likely to fight. When they do it is mainly with other males.

-john

[bernie82]

Good morning John. I know it's not 100% but even if it's 75%, I think it's the best we can do. Do you have a better way of sexing the young ones?

[John_Nicholson]

When I want a pair from a group of young I simply pick 12 that I like. Later after I pull 2 pairs I like I sell the others as young adults.

-john

[allan_mark76]

I do have to say that this subject is very interesting and I'm really learning a lot.

A- ;D