Sex determination in A. cacadouoides

[Jason]

Does anyone know at which stage of development is sex determined in Apistos? Does it happen when they are eggs or later?
Here is why I'm asking: a few months ago my cacs spawned and the young ones were 100% females. They had spawned again and after I saw the young fish swimming I added a lot of peat moss to the filter, to avoid having exclusively females. Either I overdid it, or there was a different factor involved, because now I have close to 100% of males. If it is the result of adding the peat moss, the sex may be determined more than two weeks after the conception.
Interesting, isn't it? Or even more than that: fascinating.
Jason

 

[apistodave]

Well Jason you are on the right track but you are drawing some wrong conclusions. Apisto sex is determined after they hatch and then through the next week or so. Ph and Temperature are the main determining factors. Your fish couldnt have been any sex at birth, it was determined later. Temperature is the main determining factor with Ph coming in second. Romers book has a larger explanation of this along with some tables

 

[Neil]

Jason,
I usually try to control the parms 4 up to 4 weeks after breeding, because I think that gender determination may be affected a little longer than 2 weeks. I don't know foor sure, but I like to be safe in this regard.
Neil

 

[apistodave]

Sure Neil you could be right, 4 weeks is good.

 

[Jason]

Thank you,
I thought that altough the cacs are sexless at the conception, the determination of their future must take place very soon after. Somehow this is easier to imagine to a member of a species that doesn't have room for any doubt in this matter...
I do not have the Romer's book Apistodave is referring to, I will have to find a copy soon as it must be a great book if such details are discussed there.
Jason

 

[cootwarm]

Romers Atlas

Hi Jason,

I looked for this book locally. The cheapest I found was for $59.99 plus tax at Barnes & Noble.

Anyhow, Randall refered me to this website of the Apistogramma Study Group. (Thank you Randall!) They offer the Romer Atlas for $49 when purchased with a $17 one year membership.

Total was $66, so for roughly $5 more than the local price of the book, I also got a one year membership to ASG, which I was planning to join anyhow! 8) I haven't received my book yet, (it's only been about 3 weeks) But I'm expecting it anyday now.

Here is a shortcut link to that website: http://www.apisto.com/

Michael

 

[Scooter]

Another option on the Romer book is to order it from Mike Schadle at [email protected]. He's got it for $49.00. I've bought books from him before and I believe he usually has a booth at the ACA every year (at least he did last year).

 

[radiodug]

I can get it locally for 49.00 as well if someone needs a copy, should me a reply. Shipping is gonna be probably about 5 bucks. its over 1400 pages after all. Page 155 lists that sexing takes place in the first 25 days after spawning for most apistogramma species.

Doug