Some form of sponge or nuisance??

[EakTheFreak]

Not sure where to post this photo. This sponge looking web is growing larger on one of my rocks that is on bottom of my tank near sand. It clearly doesn’t look like the healthier thing so I’m wondering if someone could ID it & if so if I should be trying to remove it from my tank?

Thanks in advance!!

Let’s go 2023!

EakTheFreaksReef

 

[bushdoc]

If you are referring to yellowish, semi translucent stuff, it does look like a sponge.
I think sponges are beneficial, either way the only way too remove sponges would be to take rock out and brush thoroughly and they would almost certainly come back.
They thrive on microplancton/sediment suspended in water and need silica for their skeletons

 

[EakTheFreak]

If you are referring to yellowish, semi translucent stuff, it does look like a sponge.
I think sponges are beneficial, either way the only way too remove sponges would be to take rock out and brush thoroughly and they would almost certainly come back.
They thrive on microplancton/sediment suspended in water and need silica for their skeletons

What will coral do if it goes near sponge. Grow over it or will sponge kill it?

 

[bushdoc]

What will coral do if it goes near sponge. Grow over it or will sponge kill it?

I do not know precise answer, but although many sponges are producing toxic substances, they usually do not release them into the water, unles you damage them , that's why I do not really recommend scrubbing rock with sponges. Again, they like some nutrients and are NOT ( usually) photosynthetic, so they mainly thrive in sump or under the rock. My educated guess, also based on running reef tanks for a decade or so is that there is no real biological warfare between corals and sponges as they occupy slightly different biological niche. I know that some would disagree.

 

[ISpeakForTheSeas]

What will coral do if it goes near sponge. Grow over it or will sponge kill it?

If the sponge is "invasive" (like the famous, coral-killing, black sponge, Terpios hoshinota) then it would grow over the coral and smother it, otherwise, the corals would probably grow normally and the sponge would grow around it (possibly even growing around/through the base of the coral without causing issues of any kind). As mentioned above, most sponges are going to be totally harmless to corals. They really do tend to occupy different biological niches, and even the invasive ones don't seem to kill coral outright through the use of chemicals (T. hoshinota, for example uses both chemicals and its faster growth rate to slow/weaken the corals and then grow over and smother them).

So, your sponge is most likely harmless, but - in the event that it's one of the few invasive ones that make their way into our tanks - invasive sponges are usually pretty easily trimmed back/controlled regardless. If yours turns out invasive and you want to remove it, there are a different threads on here that have various extermination methods you could try, but I don't know how effective any of them are.