Strange

I was doing a water change earlier when i noticed what looked like an egg floating around the tank. After a good look around i couldent find any more. I carried on only to notice my Bumblebee catfish (Microglanis iheringi) spitting out what can only be described as white eggs about 3mm across. They were like a complete circle that was cut in half and hollowed out in the middle. The same as a contact lens would be hollowed out to fit an eye.
I had a look under the microscope and they had a small outer shell and slightly darker inside. There was no sign of life at all.
There is only one bumblebee cat in the tank so breeding couldent have taken place.
The cat looks fine and healthy with no signs of stress at all.

Anyone any ideas on what these are?
I have placed some in a tub with some moss to see if there is any developments.

that is strange. could they be for want of a better description like the way cats get furballs could fish have the likes of calcium deposits that they spit up. Just the fact that there is only one in the tank. Could it have crossed with anything else in the tank.

Nessa it was like he was spitting out fur balls.
The KH in the tank is 0ppm and the GH 1.12ppm so i dont think there would be enough calcium in my water for even a snail to form a shell never mind excess amounts. But i like the way you are thinking.

After getting up this morning to 2 dead fish in the tank i spent the day observing the tank and the things that look like eggs. I should point out these are not fish eggs. They are to big for anything in the tank.
All the fish seemed stressed, verry panicky and breathing heavily. I added extra airation which calmed them in an hour or so.
I did a 50% water change vacuuming the gravel and i will do the same tomorrow etc.
Tested the water; Ammonia 0ppm, Nitrite 0ppm Nitrate 30ppm (not bad for a tank of cats and plec's) PH 6.8 (permanent pH meter on this tank).

I made a mistake placing the \"things\" in a tub with java moss. The infusoria on the moss has started to feed of them and have even made it inside. So i suspect i wont get long to observe them.
The \"things\" have gotten slightly white to the naked eye and have slightly increased in size. Maybe 4mm at this stage and have developed into a complete circle.
Under the microscope the inside looks like a storm cloud but still no movement to give me a clue to what they are.

My fear is they are part of a life cycle of a parasite and will need an intermediate host so i have removed any snails i could find and treated the tank for flukes and worms.
I am lost as what else i can do at the moment and i think the worst has yet to come.

Anyone any suggestions?

Very interesting, I have no idea what they are, but am looking forward to finding out. At 3/4mm they seem very large to be a sort of fluke, I suspect if one was allowed to develop it would eventually burst and give out a load of little versions. What is generating them in the first place would the thing to find out, it can't be small either if it is turning out these 3mm discs regularly. Did you open either of the fish that died to see if you could find a source?

It does sound like it is some sort of parasite and I think what Daragh is saying about it bursting out lots of little ones is like your worst nightmare but unfortunately could be the case. The fact that you have dead fish too is strange so there must be more going on there then you can see as your water is ok.

Did you get to look at the dead fish under the microscope? Amazing how these buggars can just arrive in the tank from seemingly nowhere. I hope you get to the bottom of it soon and dont loose any more fish. Curious to see how this unfolds

I had opened up one of the plecs but i think it was dead to long to give me a clue to what killed it.
I find it hard to beleave myself that the \"things\" are anything to do with parasites. They are way to big.
There are only a couple of possibilities i have come up with.
1; i have 3 pregnant female plec's in this tank. One could have laid eggs which the cat would have had no trouble taking from the cave and eating them. The only thing is i checked all the plec's today and they are still carrying eggs. Maybe i missed one of the females been pregnant!
2; 3 of the plec's i had only introduced a couple of days earlier. They were in quarantine for less than 2 weeks ( i know, i know) and had worms that i had treated them for. This i did and they seemed fine.

I stripped the tank today and gave all the fish a new home. I will just have to wait and see what happens.

Whatever it was I hold it is gone for good. Certainly was strange.

It is just a waiting game now.
I removed that tank today and replaced it with a fresh one. 100% fresh water( same ph, slightly lower TDS), new substrate and new decor. The only thing the same is the filter.
Hopefully this will help.
The 2 fish that died, one been a killi i have had since he was born and no where near his sale by date. the other a plec recently introduced. She was found on top of a plant. So i recon she had been darting around from stress or something irritating her. She was not light enough to flout up onto the plant.