Squamosa shell

DmitryB · 2026-10-24T18:04:18-0400

I got a Biota squamosa a few weeks ago; pretty decent size. What is this on its shell? At first I thought "hey that's a cool snowflake pattern on its shell" but I'm starting to think that's not normal? I figured Biota wouldn't have weird hitchhikers on their stuff.

KrisReef · 2026-10-24T18:39:55-0400

Those appear to be invasive clove polyps. I would not be happy if I had received this clam from anyone if I didn’t know that it was coming with these before hand. Nasty business, sorry.

DmitryB · 2026-10-24T18:41:10-0400

What's the first thing I should do with the clam??

thamnasteroid · 2026-10-24T19:44:51-0400

tunicate or bryozoan, not clove polyps

DmitryB · 2026-10-24T19:53:27-0400

I'm confused!!

I was going to take the clam out of tank and use Joe's Juice, but it's attached to the bottom glass. So...

Is this thing whatever it is going to kill my tank or ???

Decamicron Labs · 2026-10-24T22:16:45-0400

Take a picture under whites. If this is a tunicate, it is likely the genus Botryllus. If you are not dosing phyto, it will probably go away on its own. If its the octocoral, its not clove polyps (Clavularia) but instead probably a species in the collection of morphologically similar corals people are calling Sarcothelia. You may have a problem if its the latter.

minus9 · 2026-10-25T12:59:09-0400

Looks like colonial tunicates, harmless filter feeders, but they like to spread to the undersides of things. I still have some leftover from my Aussie and Solomon live rock.

DmitryB · 2026-10-25T13:11:53-0400

I got a video; there's a 4K version available for better detail.

Decamicron Labs · 2026-10-25T15:37:07-0400

Yep ascidians. Nothing to worry about. Makes sense because Biota probably grows these in an environment with a lot of food in the water column to boost growth. They eat similar stuff to clams, but giant clams can get by with only photosynthesis.

With these ‘star shaped’ ones, I’ve been told there’s two genera. One is Botrylloides and the other is Botryllus. I don’t know how updated this taxonomy factoid is. However, I can tell you that these are some of the closest things to vertebrates. They are more similar to us than to any invertebrate animal, with the only exception being lancelets. Fascinating find. I would consider myself lucky if I had an established colony of these in any of my tanks.

DmitryB · 2026-10-25T15:43:12-0400

Decamicron Labs said:
Yep ascidians. Nothing to worry about. Makes sense because Biota probably grows these in an environment with a lot of food in the water column to boost growth. They eat similar stuff to clams, but giant clams can get by with only photosynthesis.

With these ‘star shaped’ ones, I’ve been told there’s two genera. One is Botrylloides and the other is Botryllus. I don’t know how updated this taxonomy factoid is. However, I can tell you that these are some of the closest things to vertebrates. They are more similar to us than to any invertebrate animal, with the only exception being lancelets. Fascinating find. I would consider myself lucky if I had an established colony of these in any of my tanks.

Well, that's a relief! Thank you! I did wonder how an invasive polyp would get into a Biota system. I'm glad I did not send them a sternly worded email yet.