A pair of polka dot eyes on stalks peered out from the dark refuge, watching me through the shallow seawater. Several times this shy little creature had darted back from the open mouth of the shell, as if swallowed by the corkscrew hollow in which it hid.
With one knee propped against the side of the rockpool, I remained as still as I could, meeting the gaze of these black and white spotted discs that looked more like fibre optics than eyes. Bit by bit they emerged into the light, with thin antennae the colour of candied orange peel, claws flecked with light blue, and jointed legs, their pointed tips striped as if clad in sports socks.
The tiny crustacean stretched forwards and grabbed the rough stone beneath, tilting its periwinkle home, finally righting itself, before trundling off like a clockwork toy beneath swags of seaweed.
This colourful hermit crab is a West Country rarity, which, until a few years ago, was thought to have disappeared from our shores. I would have overlooked such a coastal gem were it not for the expertise of the staff at Devon Wildlife Trust leading the Wembury Marine Centre rockpool safari I had joined.
Clibanarius erythropus, its scientific name as cumbersome as the protective shell it lugs around, first colonised Cornwall from continental strongholds in 1960. However, the Torrey Canyon oil spill of 1967, and the ensuing cleanup operation using powerful detergents, virtually wiped out the local population.
The few that survived eventually disappeared by the late 1980s, only for the species to be rediscovered six years ago near Falmouth, and subsequently in other locations. Its return prompted BBC Springwatch to run a competition to give the species a common name, with the chosen winner being the St Piran’s hermit crab – after the patron saint of Cornwall, a fifth-century abbot who, legend has it, was also a hermit.
My rockpool safari group found all manner of curious critters – a golf ball sponge, lightbulb sea squirts, a tompot blenny and sea lemons. But the highlight of the excursion was the characterful St Piran’s hermit crab, staring up at me with those crazy eyes.
• Country Diary is on Twitter at @gdncountrydiary
