crabs | Cornish Rock Pools

This week I’m planning rockpooling events for next year and adding identification pages to my website….

Yesterday it was so foggy you couldn’t see the sea in front of your wellies. Before that it was raining; before that it was blowing a gale and on the one day the sun came out I was nowhere near the beach. It’s not bad for eggcase hunts – which Cornish Rock Pools junior loves – but that’s about it.

This time of year, when the short days and inclement weather make even die-hard rockpoolers like me reach for the duvet, I turn to flicking through the 2017 tide table and dreaming of sunny days and gleaming expanses of shore.

Is it too early for New Year’s resolutions? Mine is to spend (even) more time sharing my love of rockpooling with others. I’ve put all the Looe Marine Conservation Group rockpooling events in my diary and I’m also hoping to volunteer with the utterly fabulous Fox Club (the junior branch of the Cornwall Wildlife Trust), helping to run events around the county. Then there will be other events for the local scouts and home educating groups to fit in, and who knows what else. Continue reading Sharing the Love of Rockpooling →

Is there anywhere better in the UK to get up close to an array of wild animals than the rock pools? When the tides and weather come together, as they did this weekend, the rockpool creatures are hard to miss. There are eyes staring back at you from every shimmering pool.

This clump of fish eggs was dangling among some red Lomentaria seaweed. Through my camera lens the dark, metallic specks in the eggs were magnified and I could see hundreds of fish eyes staring out at me.

Fish eggs, each one a nearly-developed animal with colourful eyes.

As Cornish Rock Pools junior and I moved a rock, he shrieked with excitement. He knows better than to get close to a ‘devil’ crab – velvet swimming crab – but we watched it sculling through the shallow water. It buried itself there with just its eyes showing.

The unmistakeable red eyes of the velvet swimming crab.

This shot of the velvet swimming crab's back leg shows why it's such a great swimmer. The flat paddle and side hairs propel it through the water at great speed. — This shot of the velvet swimming crab’s back leg shows why it’s such a great swimmer. The flat paddle and side hairs propel it through the water at great speed.

It was hard to see the eyes on the next creature we found – or even to tell if it was anything at all. Still, if a shell or some seaweed starts running off, it’s a good sign there’s an animal in it. This wriggling piece of seaweed turned out to be a small species of spider crab – a decorator crab. This one was beautifully adorned with seaweed it had collected. The left claw is clearly visible in this photo and the eyestalks are just behind it (honest!).

OLYMPUS DIGITAL CAMERA — A decorator spider crab (macropodia sp.) well-covered in seaweed.

A highlight of this weekend’s rockpooling was the range of sea slugs. Some species were so small they looked like nothing more than a spot of jelly on a rock. Out of the water they lose all of their structure so we always put them in a shallow tray of water to watch them fluff up into their true selves.

An Aeolidiella alderi sea slug. This slug has a distinctive white ruff of short cerrata (tentacles) behind its head.

Limacia clavigera sea slug. This slug has striking orange-tipped clubs all around its body, with matching feathery gills on its back and ridged rhinophores (like antennae). — Limacia clavigera sea slug. This slug has striking orange-tipped clubs all around its semi-transparent body, with matching feathery gills on its back and ridged rhinophores (like antennae).

This plump sheep slug (Aeolidia papillosa) was so fluffy and soft that one of Cornish Rock Pools junior's friends fell in love with it. — This plump sheep slug (Aeolidia papillosa) was so fluffy and soft that one of Cornish Rock Pools junior’s friends fell in love with it.

Out of the water, sea slugs appear to be blobs of jelly. In the water they are transformed.

The rockpools were so full of life in the spring sunshine that we could hardly move for crabs running around our feet and anemones nestling in the sand.

An especially red dahlia anemone buried in the sand.

Right at the end of our rockpooling session I pulled back some seaweed and moved in close to the rock, looking for tiny sea slugs. It took me several seconds to realise how close my nose was to this hefty crab (at which point I gave an unprofessional shriek and nearly fell over backwards).

Fortunately it was just an edible crab. This species is generally placid and has calm green eyes, unlike the red-eyed devil crab which would probably have taken my nose and run off with it!

There were more eyes looking at us out of the pools than I can write about here, from huge spider crabs to the tiny sea spiders – as well as some creatures that had no visible eyes at all. This is a wonderful time of year in the rock pools and we’re already looking forward to the next spring tides so we can see who we meet next.