Marine creature runs, sheltering in trim beach after storm (6,4)
I believe the answer is:
hermit crab
'marine creature' is the definition.
(type of crab)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for hermit crab that I've seen before include "aquatic creature" , "Marine squatter" , "Creature inhabiting empty shell of another" , "One wearing cast-offs" , "Crustacean - tribe march (anag)" .)