Tag Archives: Hermit crab

Discoveries on my Doorstep – Rockpooling with the experts in Looe (Day 1)

There’s a questionable theory that 10 000 hours of practice makes you an expert and I may be close to ‘doing my time’ in the Cornish rock pools by now. However, I often feel I’m only scratching the surface of what’s out there. What better then, than to spend a few days on the shore with the genius that is David Fenwick, creator of Aphotomarine together with a fabulous group of fellow rockpool fanatics from Coastwise North Devon?

With layers and waterproofs aplenty, Junior and I joined them at Hannafore Beach, a site I know intimately, to see what new discoveries might await us.

 I realised within minutes that I should have brought a notebook. David’s knowledge of marine species is immense and he wasted no time in finding signs of nematode worms living inside seaweed, reeling off their names. It was windy, drizzling and cold and to make matters worse Junior sprung a leak in his wellies, but there was no doubt this is going to be a fascinating day. Leaving Junior playing at reconstructing ancient ruined cities from the rocks of a mid-shore ridge, we waded across the lower shore.

Sea hares (Aplysia punctata) were everywhere munching on the seaweed.
Sea hares (Aplysia punctata) were everywhere munching on the seaweed.

Some species were familiar. The sea hares were everywhere and so abundant that it was impossible to avoid them. This swirling cloud of purple ink in the water was a sign we’d accidentally disturbed one of them. Continue reading Discoveries on my Doorstep – Rockpooling with the experts in Looe (Day 1)

Home from Home: Quiberon in Brittany

Things have been quiet on this page the last couple of months. Cornish Rock Pools Junior, Other Half and I took an extended holiday to visit the towns and beaches of Brittany. As always our travels had a bit of a marine theme…

Est-ce que c’est un anémone?” the eager child in the dark-rimmed spectacles asks. We explain what a ‘stalked jellyfish’ is to the class of seven-year-olds. “Jellyfish!” they chant.


Stalked jellyfish - a Lucernariopsis cruxmelitensis.
Stalked jellyfish – a Lucernariopsis cruxmelitensis.

Between fascinating excursions to the fire station and the sardine factory, we are giving impromptu English lessons to a class of primary school students during our twinning visit to Quiberon in Brittany.


We have covered the words goby, crab, jellyfish and shark so far and there’s still a sea of raised hands. The children seem desperate to tell us about their finds around the shores of Quiberon. Continue reading Home from Home: Quiberon in Brittany

Rare Hermit Crab Making a Comeback

As soon as I heard the yell of excitement, I guessed what it might be. This is the species that everyone recording rockpool wildlife in Cornwall has been watching out for. For me, it was especially exciting that this one, found by Jan of Coastwise North Devon, had just turned up in one of my favourite coves, Porth Mear. 

Meet Clibanarius erythropus. Nope, none of us could remember that name either, though we knew it certainly was one. Jan decided to name little hermit crab Sydney to make things easier.

Clibanarius erythropus is a distinctive (if unpronounceable) crab. Most species of hermit crab have one claw that is considerably larger than the other – most are ‘right clawed’. This species is almost unique in having two fairly equal sized claws.  

The white spots on its eyes and its striking red legs are also a good aid to identification.

Clibanarius erythropus - A red legged hermit crab making a comeback in the Cornish rock pools this year.
Clibanarius erythropus – A red legged hermit crab making a comeback in the Cornish rock pools this year.

If you find one, please take a photo and send your record to ORKS, the Cornwall and Isles of Scilly online recording system -it’s quick and easy to do.

This warm-water species, relatively common in the Channel Islands and around the French coast, is at its northerly limit in Cornwall. It used to be found occasionally on our shores, but has rarely been recorded here since the 1967 Torrey Canyon oil spill in 1967. The last recorded sighting was in 1985.

But this year it has reappeared. There have already been at least three records from various locations around Cornwall in 2016. Could these hermit crabs be making a comeback?

One explanation for the reappearance is the high water temperatures of the last couple of years. In 2015 warm currents arrived early in the year bringing a massive bloom of the giant barrel jellyfish. These conditions could have been right for the hermit crab plankton to survive and settle on our shores. 

So now we have to wait and find out whether the conditions remain favourable for this little hermit crab to become a long-term resident in our rock pools.