Taeniacara candidi with bent spines

[Tim_Smith]

Hey guys, been breeding T.candidi for about a year or so now. I have only ever bred 4 males out of 6-7 batches of fry. I know most think temps are the reason for this, but I have tried dropping temps with no effect. Anyway this recent batch I had produced a lot of deformed fry. They all have bent/crooked spines. Probably more than 50% of the fry are effected. Has anyone seen this before? I kinda assumed that it may be due to lack of genetic diversity? With them producing so few males maybe even before I got them they were quite inbred? However I’m surprised at the amount to go from none in other batches straight to maybe over 50% of fry, I would assume it would be only a few and build with each batch.. could there be another reason? This was the batch I tried 22-23 degrees C with and I have only found one male. Who unfortunately has a bent spine. Anyway here is an image to show an example. I have separated the male and female that produced these bent fry partering him up with another female from another batch.. but I am pretty limited as they have already all come from a single sibling pair. Anyway any discussion would be valued.

 

[MacZ]

That's not necessary due to inbreeding, T. candidi are not among the species with that problem.
While I don't want to rule it completely out, I would rather presume one of the parents has a genetic defect, which in combination with the other parent's genes comes to expression.
After reading again... dwarf cichlids burn out and age faster when regularly breeding. If the parents are too old, defects also rise.

An alternative explanation might be a nutritional issue or stunted development from other causes, I can not really think of right now.

You should stop breeding with the fish you have.

 

[Tim_Smith]

That's not necessary due to inbreeding, T. candidi are not among the species with that problem.
While I don't want to rule it completely out, I would rather presume one of the parents has a genetic defect, which in combination with the other parent's genes comes to expression.

An alternative explanation might be a nutritional issue or otherwise stunted development.

They mostly get BBS… same as all my other fry and fish. I agree it could be a one off and seems likely the case with the numbers of deformed fish I got. It would be good to work out if it was because of environmental reasons or genetics. I’ll probably end up breeding with the single male I have with a bent spine with a good female from another batch and see how the fry end up. Mostly just because males are so rare for me.

 

[Apistoguy52]

Are these different from most of the other SA dwarfs? 26 gets both sexes, less than 26 more females, more than 26 more males, seems to be a pretty solid plan for Apistogramma and Dicrossus in my experience.

 

[MacZ]

I’ll probably end up breeding with the single male I have with a bent spine with a good female from another batch and see how the fry end up. Mostly just because males are so rare for me.

I'd have reservations. You can't rule out the defect being transmitted to visibly normal fish and if these and their respecitve offspring get distributed the captive population in your country might become genetically compromised.

 

[Mike Wise]

Are these different from most of the other SA dwarfs? 26 gets both sexes, less than 26 more females, more than 26 more males, seems to be a pretty solid plan for Apistogramma and Dicrossus in my experience.

These temperature-to-sex ratios basically only apply to most, but not all, apistos. Reports of collecting Taeniacara in the wild indicate that they live in very shallow and open water that can get very warm. No studies on the temperature effect on sex have been done on Taeniacara, nor Dicrossus, that I know about.