Kribensis fry all Male - Why?

[NW Cichlid Keith]

I decided to fully raise a dozen or so of my last batch. They all ended up being male. Does anyone know the cause and remedy for this? I am guessing it is temperature or PH/hardness related. If so, does it matter before the eggs hatch only, or potentially in early development of the fry?

 

[cockroach]

This could be due to hard water. Soft water produces females. Neutral water an almost even mix.

 

[darth pike]

It's usually pH based in Pelvicachromis species. I'm guessing your pH is over 7.0 if you got all males.

 

[NathanKS]

Sounds environmental. Here is a paper related to ESD in farmed fish
http://aerg.canberra.edu.au/library/sex_general/2001_Baroiller_DCotta_ESD_in_a_fish.pdf

I have never personally dealt with PH based Sexual determination, but temperature sex determination is fairly/very common in the herps I keep.

 

[darth pike]

Temp sexual determination accords in cichlids as well, apistos come to mind. But pH/hardness is far more common in cichlids.

 

[NW Cichlid Keith]

Thanks all - I may try monitored and managed soft water and see what happens next batch

 

[The Dave]

Thanks all - I may try monitored and managed soft water and see what happens next batch

It's a pH related issue, there are many scientific studies out there that show this effect in Pelvicachromis species. It's called environmentally influenced sex determination.

 

[lunsforj]

^^^yup

 

[Glenn aka sugy]

No kribbs can be known to only have o e sex this probally means everytime you breed these fish there fry will be the same sex every time best thing to do is find some one else who breeds them and gets the opposite sex that way you can swap.