4mm orange eggs (advice please)

[solitairedaxel]

This isn't the first time I've noticed them, but this time there's 4 round orange what I assume is eggs in the bottom of my tank, measuring 4mm across.

I now have serious doubts about whether my 2 bristlenose plecs are both male as I thought. I've had both for several years (not sure exactly when) and they're both about 3"-4" long now with lots of dinky bristles and they fight over the food.

Unfortunately, I have a bunch of egg-laying species in the tank so I'm not 100% sure it's the plecs.

Also in the tank:
6 (?) black neon tetras (been in there probably 2 years)
6 black widow/white widow tetras (recently added 5 as I was down to 1)
2 peppered cories (recent addition, still small)
1 albino cory (ditto)
1 (or 2?) Siamese flying foxes (had a hair algae problem a while back and heard they were good with that - unfortunately s/he is now over 2" long and doesn't seem to like the cories very much which is hardly fair on them as they're about half his/her size)

Also have 6 female guppies but I know it's not them.

I did a filter clean-out as it was making suspicious noises, then made a large water change a couple of weeks later (and found why the filter was making suspicious noises). I got the new fish about a week after that. Don't know if that triggered it, as I've had the new fish a couple of weeks now.

I estimate I've seen these orange balls in the tank 2-3 times before. I measured the nearest to the glass and it's 4mm across at the widest point which I thought makes it too big to be laid by anything except the plecs. Unfortunately, neither of the plecs are engaging in any breeding behaviour that I've seen. The only thing that makes me suspicious is I'm pretty sure the plecs are the only species that has been constantly in my tank every time the "eggs" appeared. I've kept bristlenose plecs since before I joined the forum - I think I had them and guppies and neon tetras to start with.
I accidentally bred cories before (did a water change and fed them and they went nuts and started sticking eggs all over the tank) so I don't think it's the cories as I thought their eggs were smaller.

If it's relevant, I always find the "eggs" in the front right quarter of the tank. The sponge filter is in the front right quarter and the output for the filter is back right. I have 3 caves (2 slate block-type caves and 1 fake stone-looking) and 1 of the slate caves is in the front right corner. The "eggs" usually appear a few inches in front of it and to the right but sometimes are to the left or to the right side of it.

Not sure if I posted my current tank setup anywhere but I'm currently running a 2.5' (20 gallon) tank with a sand base, a Fluval external filter and a sponge filter. (I find having a sponge filter already live is handy if I get unexpected babies; I use dual-sponge filters so I can swap a sponge if necessary.)

(Sorry for the essay. I got distracted while typing.)

Any advice appreciated.

 

[Bigjohnnofish]

method of elimination points to bristlenose...

i just measured some orange spot eggs i happen to be tumbling at the moment and they are 2.5mm across maybe 3mm at most.... so if your measuring through glass i'd say 4mm wide is about right for bristlenose eggs...

i assume the eggs are clumped together and not seperate? if they are seperate maybe it was an egg scatterer like a tetra of some kind....

 

[solitairedaxel]

Actually, they're more scattered (there were 3 separately around the front right of the tank and another at the front just right of centre). There was an egg right up against the side glass so that was what I measured.

Not sure if it's the black/white widow tetras after all, then. One of the blacks has been busy chasing another black around for the past couple of days, but the other widow tetras are pretty much ignoring the goings-on.

Seems like I only breed things by accident! I've tried breeding guppies (after the first couple of successful attempts, no babies have survived), bristlenose plecs (uncooperative), and black Venezuelan cories (both ignored me and then died on me).
I did have some peppered cories spontaneously spawn and managed to save the eggs, but only 1 survived to adulthood. Their spawning seemed to trigger the black Venezuelans in the same tank as they spawned as well (I assumed it was the peppers again and only realised it was the Venezuelans when the babies were bigger and not coming up in peppered colours) - sadly all the babies died at about 0.5".

 

[TeamSherman]

My first batch of BN eggs I found had some stray single eggs on the bottom of the tank. Maybe the main clump of eggs were eaten and only the strays were not found to be eaten? I collected the stray eggs and tumbled them but they moulded and died but I must have missed one as I found a single BN fry a few weeks later on the glass of the same tank.

 

[solitairedaxel]

I had a look at the caves (seems I have at least 4 in there as I have half a tank of bogwood and I can't see everywhere in the tank) but can't see any sign that they're being used. I also had a look under the biggest part of bogwood (it stands on "legs" so it's like a giant cave) but couldn't see anything.

In the meantime, I've removed all 4 eggs and put them in a glass jar with a bit of sand, an airstone and a bit of java moss and I'm going to keep them under observation. I'm pretty sure 2 are duds because they have a white cloudy appearance in the centre, but I left them anyway.

Just got some Malaysian Trumpet Snails today. I felt very sorry for them as everything in the tank was trying to eat them on their journey to the bottom!

Also got a microworm culture started just in case I do get fry. The adult fish like them as well, so it won't be wasted if I don't. (As I'm not totally sure who the eggs are from, I don't know what they'll eat if they do hatch out. I fed guppy fry and cory fry on microworms and they both seemed to like it...although guppies will eat anything.)