What are these mystery eggs?
We were about to temporarily move all of our fish out of their 240 l tank yesterday, in order to move it, ready for the new 640 l tank to be delivered; when my partner spotted eggs.
At first it was a cluster of eggs at the base of some Cryptocoryne, but then he spotted more eggs in the roots of some Java fern. Some of these were ‘large’ eggs of 5mm, but most were smaller — about 2mm in size – with a teardrop shape rather than being round, and the ‘yolk’ was at the top of every egg. We estimated that there were probably 80-100. We don’t believe they belong to the Peppered corys, as we have seen them breed before, and the shape and placement doesn’t fit.
In the hope that the eggs may have been fertilised, the only options in our tank where we know there are both male and female fish are the woodcats, Duringlanis perugiae and Tatia musaica. We also have groups of
Ambastaia sidthimunki and Synodontis
nigriventris but none of these are sexed. Attached are photos of the eggs — most have turned golden, while some are still white.
It turned out that there was a skinny female Honeycomb driftwood catfish in the wood which we moved with the eggs on, hence the question. Although it would be odd for this fish to scatter eggs, maybe she didn’t find a suitable cave or tube due to other fish already being there. We can’t find anything online about the colour the eggs should be. HEATHER AND SIMON
BOB REPLIES: The honest thing to do is admit that I’m not sure either. You don’t mention any other species of fish in the tank beyond the catfish and loaches, which rather rules out the commonly seen egg-scatterers that many of us have in our tanks.
The most commonly bred species from your list is Corydoras paleatus, but as you say, the placement of the eggs doesn’t fit, as these catfish generally stick them carefully on the aquarium glass or suitable plants/decor.
There are breeding reports of Synodontis
nigriventris and Ambastaia sidthimunki but they are largely of people finding fry or extra fish with nothing concrete on eggs or how they bred. This leaves the two woodcat species and of these I’ve only heard breeding reports of Duringlanis perugiae, so this seems the most likely parent. Photos of their eggs I’ve seen do look rather similar and the ‘skinny’ female may be another sign, as these can often be rotund little fish. Breeding reports do mention the female guarding eggs in a suitable cave, but some keepers report the eggs being ‘kicked out’ before hatching, so maybe this is what happened in your case.
The only sure-fire way of finding out is to hatch them and raise some fry, then see what appears — it could be exciting! Good luck with the eggs and the move to the new, larger tank. Perhaps you’ll have more fish to move into the new quarters than you first thought.