Alien v Predator

Had a walk along the beach at the Ythan Estuary today and it was very overcast with Haar and a pretty wild sea - nothing really photogenic.

Lots of rubbish lined the shoreline with seaweed and jellyfish washed up. Debris from a local storm and rough seas.

We then noticed this chunk of old wood washed up with clusters of mussels on it. A closer look revealed the shellfish were very much alive! I'd never seen this and it was fascinating to see how active each shell was as the tendrils twisted and pulsed. Just like clusters of mini 'aliens' bursting into life!

I'm not sure if they are common mussels as they look a bit different to the usual kind. Let's know if you know what they are.