Algae? Sponge?

duberii · Jan 6, 2021

I woke up this morning to find hundreds of these red blob things all over my rock (maybe they've been there a while and I haven't noticed them. They almost look like flatworms but don't move. They're attached to my rocks all over the place, and I have absolutely no idea what they could be. They're translucent(ish) with red around the rim. I was thinking red bubble algae but that doesn't really make sense since these are more flat in shape. Also, when I squeeze it, it doesn't pop. I can't describe what it feels like crushing it, but it's definitely somewhat gelatinous, but holds to gether very well.

RedFrog211 · Jan 6, 2021

Are you able to get any pictures of them in your tank? That might help ID

duberii · Jan 6, 2021

RedFrog211 said:
Are you able to get any pictures of them in your tank? That might help ID

I could try, but I doubt you'll be able to see anything. It isn't growing in clusters or anything. Each individual one of these things has its own piece that is connected to the rock. Some of them almost look like they are beginning to plate, which is both confusing me and making me think it's a sponge. I don't think it's a sponge though because the surface is completely smooth, with no openings.

duberii · Jan 6, 2021

The things in question are circled in yellow

RedFrog211 · Jan 6, 2021

If it’s soft to the touch, my guess is a type of macro algae. Did it give resistance when you took it off the rock, or did it fall off easily?

duberii · Jan 6, 2021

RedFrog211 said:
If it’s soft to the touch, my guess is a type of macro algae. Did it give resistance when you took it off the rock, or did it fall off easily?

It definitely wasn't calcified or anything. It was also pretty easy to remove from the rock, unlike some caulerpa. Definitely has less of a grip than something like bubble algae as well. I did just notice that it seems to be in areas with light, not the underside of rocks, so it very well could be some type of macroalgae

TriggerFinger · Jan 6, 2021

It could possibly be the beginning of Botryocladia skottsbergii; similar to bubble algae. Do you notice any of you cleaners or fish eating it?

duberii · Jan 6, 2021

TriggerFinger said:
It could possibly be the beginning of Botryocladia skottsbergii; similar to bubble algae. Do you notice any of you cleaners or fish eating it?

I don't have any fish or inverts that would eat anything of the type, unfortunately, so I can't really answer this. I have looked up some pictures, and it may be something along those lines. So long as it isn't toxic or anything there's no point in not letting it grow out and suck up some nitrates and phosphates along the way. Maybe later I can get a better ID.