Trochus snail has weird bumps all over shell

[ZzyzxRiver]

A lot of the Trochus snails at my LFS come with these weird bumps on their shells. When they grow out the shell looks normal. What could they be?

 

[Jekyl]

@ISpeakForTheSeas

 

[ZzyzxRiver]

I got a closer look when the snail was closer to the front of the tank and shined my flashlight onto it. It looked like tiny *barnacles*! I will take photos next time I get a chance.

 

[ZzyzxRiver]

Got some slightly better pics!

 

[ZzyzxRiver]

OK, I got a video that helps a bit, and more clues below:


First, I noticed that there are multiple openings to each ‘vessel’. They’ve also been getting bigger over time. And, right after I took that video, my cleaner shrimp’s antennae touched it and the openings shrank back and the whole thing seemed to contract. So…. A sponge of some sort? @ISpeakForTheSeas ?

 

[iseethruyou2]

Vermatids is my guess

 

[Dom]

Vermatids is my guess

I thought so too. But after the close up photo, I'm not so sure.

 

[ZzyzxRiver]

Vermatids is my guess

Definitely not vermetids. They are big soft lumps with holes in them, no shell or tube.

 

[ZzyzxRiver]

I got it! It’s some kind of tunicate, not a sponge!

 

[ISpeakForTheSeas]

I got it! It’s some kind of tunicate, not a sponge!

Sorry, extra crazy busy these days, haha - yeah, those are tunicates; neat and harmless. You could try relocating them off of the snail if you want, but it could potentially kill some of them.

 

[Reefering1]

See if they'll scoop up some of those spaghetti worms,in the sand, for you...

 

[ZzyzxRiver]

Each lump has two openings, like in this diagram. I’ll probably never know what kind but sweet to narrow it down to the particular animal! Now to check out tunicate care.

 

[ISpeakForTheSeas]

Each lump has two openings, like in this diagram. I’ll probably never know what kind but sweet to narrow it down to the particular animal! Now to check out tunicate care.

Knew I forgot something in my post:

If you want to try and help the tunicates do well, offering some phytoplankton would probably be wise. Isochrysis and Rhodomonas or a blend containing at least one of these would be my first choice. For a more intensive diet that would likely show better results, see "Table 3" in the link below:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7347631/

 

[ZzyzxRiver]

Knew I forgot something in my post:

Based on this article it looks like my silicate dosing is providing enough diatoms for the tunicates to grow! Crazy how we can sometimes accidentally succeed at something unexpected. I wonder if they’ll will ever make it off the snail shell onto the rock structure (or if that could become a problem somehow).

 

[ISpeakForTheSeas]

Based on this article it looks like my silicate dosing is providing enough diatoms for the tunicates to grow! Crazy how we can sometimes accidentally succeed at something unexpected. I wonder if they’ll will ever make it off the snail shell onto the rock structure (or if that could become a problem somehow).

Yours appear to be a bunch of solitary tunicates, so I would assume they won't be invasive like sone colonial tunicates may be.