Crab
Hermit Crab
Pagurus bernhardus
How to spot it
Not a true crab but a soft-bodied animal living inside a borrowed snail shell (a periwinkle when small, a whelk when bigger). You only see its legs and unequal claws (the right one larger) poking out; the shell itself is the give-away.
Usually seen at
0-45 m (median 16 m)
Size
Small (under 10 cm)
Habitat
Sandy bottom, Rocky crevice
Behaviour
On bottom
Where it's seen
Occurrence records around the UK and north-east Atlantic (OBIS).