Another unidentified strange creature

[Samper]

I believe that this is alive because I've been watching it change shapes for 2 weeks now. I have no clue what it is but other than shape changing it hasn't moved from this spot. Any ideas what it is?

[greenbean36191]

It's a foraminiferan. It's essentially a shelled amoeba. It's harmless.

[Samper]

We studied foraminiferans and radiolarians in zoology and I'm not quite sure that you're correct. Everything that we looked at was microscopic and definately not this large. That doesn't mean that they couldn't occur but I'm dealing with a 5mm creature when fully stretched out and I can't see any indication of a shell like the ones we had in the lab. It could very well be an amoeba because it does appear to extend pseudopodia but if so it's the biggest one that I've ever seen.

[greenbean36191]

5mm is well within the size range of forams. They range from microscopic coiled ones that you tend to look at in biology labs to some like "mermaid's pennies" and "spicule trees" which can get a few inches. Most don't look anything like the snail-shell type you see in text books and prepared slides. Another common one, Homotrema rubrum often shows up in reef tanks and is so conspicuous, it's sometimes mistaken for a small coral.

[Samper]

Alright thanks a ton. I'll keep looking for an ID but I appreciate it.

[dragonladylea]

If you could get a pic of the other side it would help but I'm thinking along the lines of a sponge, I have a nice piece of lr that came with a few spots of orange sponge like that and it has grown quite quickly.