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Re: Spawning A. Hongsloi

In a message dated 9/23/1999 9:23:49 AM Mountain Daylight Time, 
edpon@hotmail.com writes:

> From what I remember of Romer's study, sex is not determined immediately, 
>  but can be skewed some time after hatching by the ph and temperature. 

It is flexible for approx. 200 hours, but I can't remember whether that is 
post-spawn or post-hatch.

> I don't know if there is any information in how long the fry need to be 
>  subjected to a given temperature and ph and at what age to affect the sex 
>  ratios.

If you change temp or pH during the 200 hour "window", the ratio will scew in 
a sort of pro-rated manner, based on time spent at every pH and temp  in the 
time frame available.  So to some extent, it is affected by periods of 15 
minutes or less at a given pH/temp.

But the figures for the ratios work best over a large number of spawns.  IME, 
a given spawn at the right temp/pH for a 50/50 ratio can go as far as 90/10 
in either direction.

My recent experience with cacatoides has been that under <measureably> 
identical conditions, the same pair of fish will produce heavily female 
spawns for a month, then heavily male spawns for the next month.  At the end 
of for months of spawning, I have a whole lot of fry, but about a 50/50 mix.  
It's frustrating at best, but somehow still fun.

Bob Dixon
Cichlid Trader List Administrator

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