Snail Identification... Is it a Bladder Snail?

[Fugie]

I have these snail hitchhikers replicating in my newish aquarium. Their identity is a mystery to me and was hoping someone would be able to inform me.

They kind of look like bladder snails but those are a freshwater species as far as I know.

 

[ISpeakForTheSeas]

I'm struggling to make out what the snail actually looks like from the pics (the color of the snail is doing a good job of camouflaging it to my eyes), but I'd look up Stomatella snails and see if they look similar.