Male/Female

[bekko]

Thanks ranskye. You have been a big help with the tubercles thing.

-steve

[gregbickal]

Great info. Thank you. Only time will tell. Mabye that yamabuki is "undecided"

[ranskye]

greg,
ill give you an idea why it might be "undecided"
take most fish in the middle of our winter and it would be very hard to sex them off (there is no reason for their sex signs to be showing because they are not into it for itd be a waste of energy priming up the parts so early), i find it is the same if the fish has hard a rough time, they havent the spare energy and have been stressed out, i really try and leave them unhandled before spawning, i find it good idea to seperate the sexes (although not totally neccessary) and leave them and feed them and have decent fairly stable water prior to a spawn, having said that i dont particularly like to change large amounts of water leading up to spawning season unless its pretty bad. with reduced feeding over winter its ussually fine but youve got to watch it as feeding rises toward first breeding. if so i change slowly to stop the spawning triggers bringing it on an unwanted day when im not ready with my pond.
if you have a fish thats been travelled, got a bad tail, been knocked out, injected with antibitics and generally been given a few different weird worlds to think about and become stressed it might not show through a developing sickness but it will show through lack of identifiable sex signs.
if i so much as pull out and move a cage of brood fish once or twice before spawning theyll give me reduced eggs. some species will not breed for you at all, koi are not so finicky but you need to be aware of this fact.
so if you leave it be for a couple of months (i think you are coming up toward spawning season) feed it and keep it happy and not annoyed, keep the water ok, then you should find it showing then. i check em ten seconds before pairing them up myself. and stay away from huge changes in the weeks prior to wanting to spawn, to stop it going off uneccessarily.

[estanque_koi]

Have you heard about the "genital papillae"? According to a F.A.O. technical book on carp culture that is a reliable character for sexing common carps, hence it should work for Koi also. This character is of course useful in mature individuals during the breeding season, might not be clear in other cases.
I'm attaching the drawing. Also a couple of pictures.
Hope this might help.

[GCSpyder]

Quote: Originally Posted by estanque_koi Hope this might help.

This most certainly does. Thanx for the pix.

[bekko]

Thank you for the photos Diego. I have stared at that FAO drawing several times and never made much sense of it. The text says the papilla is behind the gonophore in females and in front of the gonophore in males. In male koi, I see something that looks similar to the genital papilla in tilapia, but don't see anything like that in females.

http://www.fao.org/documents/show_cd...E/X5085E00.htm

-steve hopkins

[gregbickal]

This ochiba looks male to me. Anybody else agree ?

[koifishgirl]

Hi Greg I am glad you are on the forum now as I need to ask you a question. I want to spawn my koi tomorrow and have put the filter box in the spawning pool and seeded with a piece of established filter. I also started my culture with hay and ferterlizer and was wonder if the culture would be ready by the time the fry hatch and if I can put the eggs in with the culture, or do I need another clean pool of water that has been establish with a good filter and started with an established piece of filter.
The spawning pool is 330 gallons and the fry pool is 1000 gal. and I am going to be using two heaters to keep water good and warm at night when the temp drops. Anything I need to do different?

And as for the koi I dont know. It looks like the vent has got a egg coming out now.