Apisto. gephyra

[Cichlids1]

I have a group of 5 A. gephyra in a 15g planted setup full of chain swords and flower pots. They are wild fish that I had delivered to me at the ACA in NJ this summer. They appear to be 3 female and 2 males. Aggression is almost non-exisitant. They are spawning for me about every 3 to 4 weeks but I have yet to get a single egg to a wiggler. I've let the fish try to raise them, I've pulled batches and tried to hatch artificially...nothing. The pH goes between 5.8 and 6.0. Temp in 80 to 82. Weekly waterchanges with an RO/Tap mix. Even tried some peat to get the pH even lower. I figured if they spawned, something must be right or at least close. I've read in various places that the eggs will not develope properly if the pH is too high, but I cannot find any reference to what too high might be. Has anyone had any luck with the gephyra? If so, what was their setup like? Should I try to drop the pH some more, maybe to the low 5's? The Dicrossus filamentosa that share this tank also do the same thing. Spawn every 3 to 4 weeks with the same results. I was thinking maybe the alpha male might be sterile, but I find it odd that the male apisto and the male filametosa would both be shooting blanks...any insight would be much appreciated. thx, Ken

 

[Neil]

Ken,
I have had similar results with a number of very soft water species. The way I usually deal with them is to "Go Way LOW". With wild species like gephyra I keep the pH below 5. Their wild biotope water conditions are in the 4 to 4.5 range, but I suspect that the eggs will develop fine in just under 5. It is my assumption that the eggs of certain fish will only hatch at a particular pH level and that they are susceptible to bacteria or fungus above that level. D. filamentosa eggs would fall into the same category.
So I think that 3 things are important here. 1. Drop the pH below 5, if you can. 2. Use straight RO water. Here again the natural water values of both of these fish are less than 1 degree hardness and you will have that with everything else that goes in your tank (i.e., food, gravel, etc.) Plus, RO water is not pure water. 3. Achieve a low conductivity via water changes. I do fairly significant water changes and often when I am working with a tough fish.
Once these fish successfully spawn it is likely that you can ease off the "Go Way LOW" rule because their babies (tank-raised fish) will often spawn in less acidic, soft water.
I love that little fish and I hope that you have success with it. Neil