sex ratio of spawn myths

[marktrc]

I read a few theories on what affects a spawn's male to female sex ratio. Some say temperature or size of the breeding pair individuals or age of the breeding male or female. Could anyone please share their real life experiences or experiments.

Ty

[indjo]

Thus far I rely on:
1. first 3 spawns of female. First spawn may give me 90% male, second about 50-60%, third about 40-50%
But this also depends highly on the temp when the fry hatched. so .....

2. Temperature; higher temps produces more males than females.
A 4th or more spawn of female in low temperature may produce 90% females.

[Basement Bettas]

Originally Posted by marktrc

I read a few theories on what affects a spawn's male to female sex ratio. Some say temperature or size of the breeding pair individuals or age of the breeding male or female. Could anyone please share their real life experiences or experiments.

Ty

I'm the QUEEN of all female spawns. Have had most of mine here in TX be 200+ fish and ALL girls. Close to 10 spawns all girls.. and the others were very few males. Amazing I finished 3rd over all on my girls.. lol. I'm getting a lot more males now.

Difference.. I use RO and was reconstituting with RO Right. After some issues and I started to test my water I found the RO Right was just repackaged sea salt. I had no gh. ph was below 7.0 and kh was like 3 and the TDS was 250. Bleck!!

Sooo... changed how I add minerals. My ph is now 7.2, gh is 3-4 and kh is 5-6. TDS is around 150. Add a splash if mico nutrients and much happier plants and fish. BIG plus is now I have males.

Other consideration is ammonia in a spawn tank. Could be it gets high and affectes the fertilization or early formation of the fry. Had issues with that too till now I keep ammonia next to zero.

My experience with the all female spawns didn't make a difference on fish size or temp.. as had them with variables there.