Something weird in my tank

[Hades]

Hi everybody,

this week i suddenly saw this mysterious "blob" appear in my tank.
It was bright bloody red, looked like a jelly consistency (with a few hair like strings on top).

I tried to take some out to have a better look and it seemed to shrink at the touch.
???? It shrank to half the size when my tweezers touched it.
It seemed to "retract" in the plants/soil.

I couldn't grab it and didn't have the time ATMITAS () so i decided to postpone the examination to the next day.
But then it got really weird.
It totally disappeared over night...

No trace to be found when the lights came up again.

I don't think the fish or shrimp ate it because they were hanging out next to it (and even on it) but showed no interest at all. And there was no trace of it left whilst it was quite entangled with the plants so i would expect that there was some leftover traces if they would have eaten it..

Any ideas what this is (or was)?
Cheers!

 

[X3NiTH]

Not 'The Blob' but equally fascinating, my money's on it being a 'Red Slime Mold'.

 

[Simon Cole]

I think it is a mucous ball secreted by annelid worms (white thread things). I would guess that the mucous was secreted in response to copulation, which is comparatively rare in oligochaetes - there is a number of them and the mucous substance aids in copulation. Some worms use mucous nets to feed, but they do not usually swarm at the same time, so feeding behaviour is unlikely. The red colour is from carotenoids, so they are probably also detritivores, feeding off carotin-enriched fish or shrimp food, or excreta. Typically mucous dissipates quite quickly, whereas a slime mould might persist (although I have observed fenland examples that might sit on fresh water). The idea of an microorganism assemblage such as a filter column/tube or a holobiont also crossed my mind, but I think that is far too unlikely. Annelid mucous balls are actually quite rare - congratulations on capturing one.