Too many females

[Drammy]

Hi all,

I worried about this after reading about how the ratios of M:F can vary with water parameters...

Until last a few days ago I had 22 3 month old Apistogramma Agasizii juveniles, 3 males and 19 females.

A few days ago I switched off the lights to go to bed and one of the males jumped out of the tank, startled by the lights out. The really annoying thing is I heard the splash and checked all around the tank (its on a kitchen unit) but for some reason didn't check the floor.

Anyway the next day I found a rock hard Apisto male on the floor - gutted!

So I now have 2 males, one of which I would like to keep. I therefore have 1 male and 19 females to try and get rid of. I doubt I am very likely to get a LFS to take this ratio of fish.

So does anyone want any female Apisto Aggys? I live in Leeds, UK.

 

[jose_vogel]

For me, it´s very useful to manage the water temperature in orden to manage the sex ratio.

The breeders in my country doesn´t sell the females at a "fair price" (A. baenschi male: USD 15, female: USD 50); so I let the fry grows at lower temperatures.

 

[Drammy]

Yeah, I will do next time

IS it just temp then - I thought pH had a factor to play...

 

[dw1305]

Hi all,
Drammy, I'm not sure about A. agassizii, but my first spawn of A. cacatuoides were 100% female. The temperature was 25oC, fortunately Kat (on this forum, but now in Germany) took all of these (about 30).

I raised the temperature to 27oC, but everything else was the same (rainwater, pH about 7, conductivity about 130microS.) At these parameters I get about 1 male for every 2.5 females. I've given away a few females, but I've struggled to give away any more, at present I'm considering what to do.

The local LFS (Parker's in Iron Acton) will take 1m 2f, but would prefer pairs. Meaning I accumulate spare females over time. I won't raise the temperature any higher, as I have Otocinclus in the main tank, although I might try pulling the female and eggs/cave to a smaller, warmer breeding tank after spawning.

cheers Darrel

 

[electric eel]

here is a quote from cichlid atlas volume 2 that might clear things up a bit.i don't think from what i've read it's still completely understood or documented
"sex differentiation in the offspring of all the apistogramma species investigated to date(n=33)is controlled in the main by two environmental factors:temperature is(usually)the dominant controlling factor,the ph value a cofactor which becomes dominant within a particular temperature range.in the majority of cases high temperatures(29C) and low ph values(<6)encourage the determination of male offspring,while low temperatures(23C) and high ph values(>6)favor the determination of female offspring.at intermediate temperatures(around26C)the ph value has a significant effect on the sex ratio of the offspring,while this is not the case at the extremes of temperature" this is a very interesting book.if you don't have it its well worth the money(i'm patiently waiting for the 2nd edition english version of atlas 1 to be released).the way Dr.Romer expained it to me in atlanta at the aca(i hope i'm getting this right) is that that it is easier for males to aquire a territory to defend if they are spawned early in the season and since most males defend super territories with multiple females in them it tends to be easier for them to get accepted into one of these groups if they are spawned later in the season then it would be for a male to displace an already entrenched male so conditions early in the season are more conducive to production of males(or mixed sex spawns) and mostly females are born later in the season.

 

[Drammy]

Thanks a lot guys! Useful as always...

Wish I'd understood this a bit better when I started!

 

[Mike Wise]

You could always breed at low temps & higher pH one time and the next at a high temp and lower pH. In theory, you should get 1 spawn of mostly females and 1 spawn with mostly males (hopefully, the spawns will be about equal in numbers of fry). If the spawnings occur just a few weeks apart, then they should mature at about the same time.