??Temp?? Male or Female

[Travis_Conklin]

I recently had a spawn of Apistogramma Cacatuoides out of the fry, I had 13 make it, and they are about 14 weeks old now. Out of the 13 I believe if not all are male there may just be one female. I have heard that temp. plays a major part in this and was wondering what information anyone has on it. If they do have info great...lets share it here if not could you point me in the right direction...I'm sure it has been discussed here but I have failed to find it thus far. Thank you in advance.

 

[aquaticclarity]

With Apistos temperature is the biggest sex detrminin factor. Higher temperatures equal more males. Aim for 77-78F to get a good split of both males and females.

Jeff

 

[Travis_Conklin]

Thanks

Thank you for the info.

 

[ste12000]

Interesting subject and an important one that rarely gets a mention on here..Lets keep this subject going and see if we can get some detailed reply's with peoples experiences.
When is temperature critical? when is sex determined?
Does the temp have an effect on sex ratios when the eggs are laid? or when they hatch? or is it when they reach sexual maturity.
If Apistogramma are harem spawners with multiple females breeding with only one or two dominant males in the wild, then does it not suit the species to produce more female offspring than males?
If temperatures higher than 80f produce more males then surely some species from warm amazonian streams would die out after a few generations of male heavy broods??

 

[Travis_Conklin]

Reply

I would also like to know about when it happens. I know that mine where in a tank which had a pretty much constant temp. of 80 and still are in a tank at 80. I have the tank which I am going to breed in set at 77, so as soon as I pick one of the best looking males I am going to breed back to his mother because I have lost the father of the brood.

 

[jonese]

Also does the temp change for different species? i.e. say for one specie from Venezuela it's 77-78 for a good ratio of male to female. would the temp be the same for a specie from Argentina? and how best to determine what the temp is jmtb

 

[Mike Wise]

This has all been reported in the following:

Römer, U. & W. Beisenherz. 1995. Modifikatorische Geschlechtsbestimmund durch Temperatur und pH-Wertbei Buntbarschen der Gattung Apistogramma in Greven, H. & R. Riehl (ed.) Fortpflanzungsbiologie der Aquarienfische. Birgit Schmettkamp Verlag, Bornheim. p. 261-266.


Römer, U. & W. Beisenherz. 1996. Environmental determination of sex in Apistogramma (Cichlidae) and two other fresh-water fishes (Teleostei). J. Fish Biol. 48(4): 714-725.

Römer's Cichlid Atlas 1.

If you do a seach of the forum you will find many entries about this.