choosing genders???

choosing genders???

it is true that you cn choose the genders of your fish by temp. but do you think it is right?

 

I've heard it works with guppies, but I can't remember which temp is supposed to yield which gender and I don't know if it works with all fish.

I know that with my african cichlid fry I tend to get more females than male and the tank temp generally stays around 80*, but I haven't tried lowering the temp to see if I get more males.

-Chelle

 

Ive too heard it, and I really dont have a problem with it, ive heard that the amount of seamen a mammal produces can determin the gender of the babies.

 

Actually, that one's not true because each sperm will carry either an X or a Y chromosome. And since only one sperm can fertilize an egg, it has a 50/50 chance of being either sex. So no matter how much sperm is released, the only thing that matters if what chromosome the one that gets the egg has.

My genetics class didn't cover fish so give me a minute and I'll do a little research and get some details on how sex determination works for them. I have a feeling that if it really is temperature related it probably has to do with hormones turning certain genes on or off at critical times.

-Chelle

 

Oh, alrighty, well i had herd it via word of mouth so your right. again im still in high school so I havent had much in the way of genetics :shock:


EDIT: But isnt their a chacen that after a while more X's will be produced then Y's or vise versa?

 

:shock: I didn't know temp would affect the gender of a fish. This is kewl, so what do you have to do to get more males?

 

Not really. All spermatogonium (the cells that become sperm) contain an X and a Y. During spermatogenesis the cells will go through chromosome replication then a couple of divisions. So a single spermatogonium will end up producing 4 sperm. 2 with X's and 2 with Y's.

Here's a good diagram - ignore the autosomes (A & a):


There is a chance that something can go wrong during the division process and cells can end up with weird numbers of X's & Y's. That can result in things like Turner Syndrome (progeny/offspring that's X0 - no second x or y), Klinefelter Syndrome (XXY), Metafemales (XXX), or males/metamales (XYY). But that's somewhat rare.

Wow! It's been years since I took Genetics or Cell Bio. I'm surprised I actually remember this stuff.

-Chelle

 

WOOOOAH, Thanks for the info, took awhile to understand but helpful. Never thought id have a genetics lesson in a fish fourm! :lol: Thanks :y_the_best:

 

I've heard that temps can influence the sex of guppies but i don't remember which temp influences which sex. I don't really see the problem with it as it isn't artificial.

 

well this has happend with my platys. i usually hav the temp. around 79 o and i have had all females. i heard about this somewhere in a book and i think for males it is around 81o-82o thank god no more males in my batch of fry. one male is enough!!

 

I want more males. They are so beautful. I have one female fry that has a blask tail thought she is also beautful. But I seem to have 2 males for 44 fry so far although the last 7 are only 1 and 1/2 weeks old so I am not sure. I would love to have a few more males. But I keep my tank about 80.

This sounds like a cool experment (nothing that will hurt the fry though of course). I will let you know if I get any different results from my new fry.

Also doesn't the water temp determine the length of pregancy also. My mom had her first 2 batches 30 days apart but the last one was only 26 days. not that I expect her to be right on target but I thought 30-90 was the adverage. I guess they are like humans. I kids wanted out early to all 3 of them were born early. My first son was 1 month early my 2nd (only daughter) was 12 weeks early and my last was 6 weeks early. Maybe fish are the same way?????