What is this on the side of my Bowerbanki?

[Soren]

Have yours ever caused any problems or do you remove them all? Because if this guy is no harm I might let him be.

I have never had problems with them, but I have my live rock shipment in a separate tank so far since delivery in March 2022 while progressing on my main build. My live rock is in a 90g tank alone with only the addition of 4 pink Smith's damsels and some clean-up-crew such as blueleg hermit crabs and astrea snails.

From what I can see, I'd guess either a Thorny Oyster (Spondylus sp.) or a Jewelbox Clam (family Chamidae). They're harmless filter feeders.

As a note on scallops, they have the little "tails" at the back of their shells that make them easily identified.

Good call on the jewelbox clam. I have some that look like these as well, but I think the ones I have that fit the description given for the ID request more closely match the thorny/spiny oyster ID. Of course, now I am finding more information and might have to consider rock scallops, though Crassadoma gigantea species seems too large to match my 1/2"-1" bivalves.

The main think I note is that my jewelbox clams seem to have the smaller half of the shell more on the surface of the rock with the larger portion embedded while what I assume are thorny oysters or rock scallops have the hinge embedded in the rock more or less perpendicular to the rock surface.

 

[Soren]

Do scallops and/or oysters have siphons that extend out of the gap in the shell when open, or would this be an identifying factor for clams?
The ones I have that seem similar to the original ID request definitely have siphons that extend out, so now I am suspecting they may be jewelbox clams in different orientations to the rock.

 

[ISpeakForTheSeas]

Aquarium Invertebrates: A Look at Some Azooxanthellate Epifaunal Bivalves

James Fatherree explores the biology of non-photosynthetic clams, scallops, and oysters commonly encountered by reefkeepers. While most of these bivalves are not impossible to keep with advances in captive reef nutrition, their surprisingly high dietary requirements make their husbandry difficult.

reefs.com

The mouths look exactly like the jewelbox clam pictured in this article. The one in my tank has tiny little light orange whips on its body. Do the jewelboxes have those?

I honestly can't see the whips in the pic or video, but my thoughts would be that if the orange whips are soft, they're probably something growing on the clam rather than a part of the clam itself. If they're solid/hard, then they may be a feature of the clam's shell, as many jewelbox clams have interesting spines.

 

[ISpeakForTheSeas]

Do scallops and/or oysters have siphons that extend out of the gap in the shell when open, or would this be an identifying factor for clams?
The ones I have that seem similar to the original ID request definitely have siphons that extend out, so now I am suspecting they may be jewelbox clams in different orientations to the rock.

From what I've heard, oysters and scallops both lack siphons - so if your specimens have siphons, they're extremely unlikely to be oysters or scallops. Jewelbox clams do have siphons, so that would be my guess if yours have both spiny shells and a siphon.

 

[Soren]

From what I've heard, oysters and scallops both lack siphons - so if your specimens have siphons, they're extremely unlikely to be oysters or scallops. Jewelbox clams do have siphons, so that would be my guess if yours have both spiny shells and a siphon.

That is what I was suspecting after this research today. Thanks for confirming. Mine are most likely jewelbox clams.

 

[EeyoreIsMySpiritAnimal]

Yea looks like a scallop they can take over tanks if giving the opportunity.

You keep saying that, but "can" and "will" are not the same. Besides, what's wrong with more cool filter feeders?

 

[Pico bam]

You keep saying that, but "can" and "will" are not the same. Besides, what's wrong with more cool filter feeders?

Eliminate possible threats imagine a tank covered in them. I've seen them, I Was always told to kill them with fire. You ever cut your finger on one? Ever pick up a large bristle worm? I dont like those either. Whats better than 1000 little razors in the tank?

 

[Rtaylor]

Yea looks like a scallop they can take over tanks if giving the opportunity.

What? No. It’s a harmless (beneficial) filter feeder. Let it be. It’s a great hitchhiker. Not sure exactly what type of bivalve it is, but I got a bunch on my live rock. Completely beneficial. Absolutely no downside.

 

[Rtaylor]

Eliminate possible threats imagine a tank covered in them. I've seen them, I Was always told to kill them with fire. You ever cut your finger on one? Ever pick up a large bristle worm? I dont like those either. Whats better than 1000 little razors in the tank?

You’re one of those afraid to get some ocean in your reef huh? Biodiversity is your best friend. Thinking like yours is truly over the top and detrimental.

 

[EeyoreIsMySpiritAnimal]

Eliminate possible threats imagine a tank covered in them. I've seen them, I Was always told to kill them with fire. You ever cut your finger on one? Ever pick up a large bristle worm? I dont like those either. Whats better than 1000 little razors in the tank?

Like I said before, you obviously don't want a reef tank/ecosystem; you can't control every hitchhiker and potential pest without undermining the process.

That's fine for you, but giving advice based on your model of" reef" keeping is a disservice to those who value the diversity.
@Rtaylor hit the nail on the head...

Thinking like yours is truly over the top and detrimental.

 

[Pico bam]

Yawn