Are these eggs fertile?

[JasonG2003]

Hi, this is my first post.

I was wondering if these Congo tetra eggs are fertile. I have a school of Congo tetras that breed on average 3 times a week, but their eggs seem to always turn white. The yolks turn white, but the egg case remains clear and somehow gets larger.

I am holding the eggs in a small 2.5 gallon tank; the pair of Congo tetras paid their eggs in here before transferring back into the main tank. I have a sponge filter, heater set to 78 degrees F or 25 C. I also put some alder cones and guava leaves.

Any help will be greatly appreciated, thanks!

 

[Andy Sager]

When an egg is not fertilized, the first thing that happens is the yolk will "die" in a day or two and usually turn white. Soon after that, the entire egg will turn white. If just the yolk stays white and there is no fungus developing on the egg, I would leave the eggs alone as the embryo may be what you are seeing turning white. At that temperature, the eggs should take about a week ( 7 days) to hatch. A little warmer and the eggs should hatch in about 5 days or so but IME, rapid hatching eggs through temperature weakens some of the fry.
Just an FYI, if the egg is dead, the whiting process of the whole egg should only take about a day-day a half.