collecting eggs of Rivulus magdalenae

This days I spent every evening a few minutes to search for eggs in a spawning-mop, which I put into my tank with a pair of Rivulus magdalenae.
The tank has plants in it too - but - they go to the mop to lay some eggs.
The harvest is poor - most time I find only 2-4 eggs, sometimes six of them and only once I found ten eggs. This happend on thursday evening - I almost did not belive my eyes :-).

I tried to store the eggs in a small box of water - don't do the same - it's no good idea. All water-stored eggs went fungus - at last at day three of storage. Even when I added alder-uvula to the water and even by using sera mycopur!
This was a frustrating experience.

At the moment I store the eggs in peat - the very-wet-peat did not work too - best was not-so wet peat (no water at the edge of the box!) - and even there, a few eggs where lost to fungus.

So for now I'm wondering, why this species is called an fairly easy species...
I will take my time to monitor the egg-production - it seems to me, that it does not matter how much food they get and which kind of food I give - the amount of eggs does not change.
A change of water does NOT animate them to lay more eggs - I receive the impression, that fresh water is not good for egg-production - very strange for a killifish...

The Rivulus species are generally not often seen in the hobby - I have to find a way to get more healthy eggs to spread them to some friends around...