What is this please good or bad?

[Bendyboyben]

Maybe a sponge

 

[carey]

If you poke at it does it squish or it it soft? If so I would say sponge. If its hard and doesnt come off easily it could be coralline algae. Is this a new rock or anything?

 

[Bendyboyben]

It's squidgy but won't come off easy and all the rock is fresh bought from my lfs

 

[carey]

I'd say its a sponge then. Perfectly harmless filter feeders.

 

[Bendyboyben]

Thankyou

 

[Gregcoyote]

Scypha or commonly referred to as pineapple sponges volunteer often on live rock. They are harmless, unless it gives you the certainty you can now grow sponges in your tank. These little guys grow under conditions other sponges would find lethal.

 

[Bendyboyben]

These guys are on a new piece of rock that I just got so I hope the conditions aren't a that bad lol

 

[Gregcoyote]

These guys are on a new piece of rock that I just got so I hope the conditions aren't a that bad lol

Thats not what I meant. You have to have pretty good water to get these to grow.

Repost;


The calcareous sponges, use calcium to form their "skeleton." (spicules) The so called "pineapple sponges" are Class Calcarea sponges (as opposed to Class Demospongiae, which use silica and is a far more diverse group.) But whether they are from the Genus Scypha (the snap id of pineapple sponge) is a difficult question. I suspect these sponges are showing up more frequently, due to the widespread use of salt mixes with higher than normal seawater levels of calcium.

 

[Bendyboyben]

Sorry misread it haha