Fertile vs Infertile Eggs: How to Pick the Right Eggs from Your Spawning Mops

Fertile vs Infertile Eggs: How to Pick the Right Eggs from Your Spawning Mops.

Fertile vs Infertile Eggs: How to Pick the Right Eggs from Your Spawning Mops; When picking eggs out of spawning mops, it's important to only select the fertilized eggs.

Unfertilized eggs will slowly break down or be eaten by other organisms in the tank, and this can cause fungal growth which can spread to sensitive fertilized eggs.

How Do You Tell the Difference?

One of the easiest ways is the colour of the eggs. Most eggs when fertilized will take on a clear/translucent colouration, almost like glass or a water droplet.

The unfertilized eggs will be a lighter colour, slightly cloudy or more opaque - meaning they aren't as see-through/translucent as fertilized eggs.

Why Does It Matter?

While it can be tempting to up your production numbers by trying to hatch out these unfertilized eggs, they can be the difference between a clutch hatching out successfully, or clouding out entirely.

A Real Example

The eggs used in the images above are two different Pseudomugil Luminatus eggs found on the same spawning mop. The left is infertile, the right is fertile.

It can be hard to see in photos, but with practice your eye will quickly learn to spot the difference when harvesting from spawning mops!

If you're hatching out Pseudomugil or other egg-scattering species, our Available Fish range and live plants collection (great for natural spawning cover) are worth a look. A gentle fry-safe sponge filter also helps protect delicate fry once eggs hatch.