White tentacle out of the clam and white leaf vessel on the shell. What are they?

[rowenaad]

I have this clam for a year and half. I just flipped the clam yesterday and see the side of the shell that i wasn't able to see and i have noticed a lot of things going on there.

Theres a white tentacle coming out of the edge of the shell in the top left corner thats searching....for food i assume? what can it be? Im pretty sure theres a pea crab living in the clam cuz ive seen empty shells twice but never saw the crab itself, but other than that ive noticed nothing.

Also to the right of the shell towards the edge, theres some white leaf vessel like stuff forming there. What is that?

Any advice is appreciated.

 

[Dburr1014]

Neither are part of the clam.
Looks like algae and maybe a vermetid snail and other type of worm.
They may irritate the clam(or may not).
IMO, my ocd says use a soft toothbrush and clean it. That's up to you.

 

[ISpeakForTheSeas]

The white stuff on the right seems to be sponge growth (should be harmless to the clam); the thing on the left is too small for me to say for sure, but it's acting like a peanut worm or similar detritus feeder, which would be harmless.