Help ID these (mussle like)

[rpeters]

Need some help with ID of these two and possible impacts they have. The first (larger of the two) was found inside a stock of a pink tip touch colony fragged in two with a friend and had polyp bailout almost immediately for both of us so think it was likely doomed before we got it but not sure if any relation to this inside of it. The second is smaller and was found in QT tank. The only thing in the QT tank was a fish purchased at same time and was a fresh start up so wasn't in tank prior to adding the fish. The larger has a smooth surface when the smaller has a texture surface like clam/mussel. looking on https://www.lionfishlair.com/hitchhikers-guide it looks like the bivalve but that was listed under stationary and moving things so wasn't sure. Any help is appreciated

 

[Jose Mayo]

The radiated aspect of the shell resembles Atlantic Ribbed Mussel (Geukensia demissa), an atlantic mussel, maybe in the juvenile stage.

But I may be wrong.

Best regards

 

[ThunderGoose]

Not sure of the ID but great job on the photos! Especially including the ruler for scale.

 

[rpeters]

The radiated aspect of the shell resembles Atlantic Ribbed Mussel (Geukensia demissa), an atlantic mussel, maybe in the juvenile stage.

But I may be wrong.

Best regards

I started thinking something similar but wasn't sure it they were capable of getting inside a coral stock and if so would it impact its health.

Also one thing to add the small one was attached to side glass of QT and moved about an inch a day

 

[rpeters]

Not sure of the ID but great job on the photos! Especially including the ruler for scale.

Thanks, much easier when they aren't in the tank

 

[Maritimer]

That larger one almost resembles a little flame scallop . . .

~Bruce

 

[Jose Mayo]

Also one thing to add the small one was attached to side glass of QT and moved about an inch a day

Yes, this mussel species usually inhabits the mud and has the ability to move slowly with its muscular "foot". They have tolerated a wide range of environmental variations, from brackish water to waters twice as salty as the sea. They are filterers and very good consumers of nitrates and phosphates, so I do not think they are bad acquisitions for the aquarium.

Best regards