Tag Archives: Rockpooling

Top 5 Fierce(ish) Rockpool Creatures

As you might imagine, we’re fans of nature documentaries in this house and we’re all looking forward to watching Steve Backshall’s new series, Fierce. It’s got me and Cornish Rockpools Junior thinking about opportunities to meet ‘fierce’ wild creatures closer to home.

Of course, these animals aren’t exactly fierce, they’re just equipped to survive the evolutionary arms race with attitudes, weapons and chemicals that aren’t very human-friendly.

You don’t need a plane, a film crew and a ton of equipment to seek out an encounter with a well-armed rockpool ninja. This weekend’s massive low tides are the perfect opportunity to head out onto the shore and check out our top 5 fierce(ish) rockpool creatures.

So, check the tide times, grab a bucket, put on your wellies and take a look…

5. Small spotted catshark

Scyliorhinus canicula - small spotted catshark or dogfish stranded in a Cornish rock pool
Scyliorhinus canicula – small spotted catshark, also known as dogfish – stranded in a Cornish rock pool

These small sharks, often known as dogfish, sometimes become stranded in pools during the very lowest of tides. They’re not at all aggressive, but it’ll sound impressive that you’ve met one. They have incredibly rough skin that used to be used as sandpaper. In some places you can also find their egg cases and those of their larger cousin, the nursehound, attached to seaweed. They take around 7-9 months to hatch out so never detach the egg case from the weed.

The developing greater spotted catshark can be seen at the bottom of the eggcase
The developing greater spotted catshark can be seen at the bottom of this eggcase

4. Snakelocks anemone

This snakelocks anemone looks like it's had a fright - the tentacles were being picked up by the current
This snakelocks anemone looks like it’s had a fright – the tentacles are being picked up by the current

This anemone is common in rockpools all around Cornwall. It’s easy to see how it gets its name from its long snake-like tentacles, which are usually green with purple tips, but sometimes a dull-brown. They’re from the same family as jellyfish and have stinging cells which shoot poisonous harpoons into anything that touches their tentacles. It’s best not to touch this anemone as some people have a reaction to the sting. If you do touch one be sure not to rub your eyes because stinging cells can attach to your skin – wash your hands as soon as you can.

Cornish Rock Pools Junior is convinced snakelocks anemones can eat your foot. That’s unlikely, but watch what they do to this fly…

3. Worms

Worms are often buried in sand and mud burrows - if disturbed they can shoot out their jaws and give a nasty nip.
Worms like this ragworm are often buried in sand and mud burrows – if disturbed they can shoot out their jaws and give a nasty nip.

An unlikely contender, but there are several species of worm on the shore that can be pretty fearsome, especially the larger ragworms. These animals have an extendible jaw that can shoot out and deliver a painful bite. Others, like the bootlace worm secrete a toxic mucus. Handle with care!

Other finds... a bootlace worm. These worms are many metres long when fully extended, but are usually found in a tangled ball like this.
A bootlace worm. These worms are many metres long when fully extended, but are usually found in a tangled ball like this.

2. Compass jellyfish

Compass jellyfish - showing its distinctive markings
Compass jellyfish – showing its distinctive markings

Like the anemone, this jellyfish is armed with lots of nematocysts (stinging cells), but far more powerful. These jellies with their distinctive V-shape compass markings can give you a painful sting. Jellyfish don’t live in the rockpools but are often washed in by the winds and tides, especially in the summer and autumn months. They’re beautiful creatures and well worth a look, but remember not to get close or to put your hands in the water – their tentacles can be hard to see, very long and can become detatched from the main jellyfish, so it’s not worth the risk (yes, that’s talking from experience… I’m a slow learner). There are lots of different species of jellyfish and some, including the massive barrel jellyfish, are harmless, but if you’re not sure, stay clear!

Jellyfish tentacles can be hard to see, so be careful not to put your hands in a pool that has a jellyfish in it (e.g. to take underwater photos of tentacles like this one!)
Jellyfish tentacles can be hard to see. It’s best not to put your hands in a pool that has a jellyfish in it (e.g. to take underwater photos of tentacles like this one!)

1. Devil crab (Velvet Swimming Crab)

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A velvet swimming crab (devil crab) shows off its red eyes.

The top fierce creature award, as voted by Cornish Rock Pools Junior who will not go near them, is [insert fanfare of your choice here]… the velvet swimming crab. This crab, known by Junior and many others who’ve met it as the ‘devil crab’, is afraid of nothing and is always quick to use its pincers. Their dark shells and gleaming red eyes give these crabs a sinister look to match their temperament. They’re brilliantly suited to hunting in the rockpools and shallow seas. If you dare to look closely at one (see ‘How to pick up a crab’), you’ll see that their stripy back legs are flattened into paddles, making them excellent swimmers. Watch out for them lurking buried in the sand, with only those red eyes showing.

As soon as you approach a velvet swimming crab will stand on its back legs, its claws raised, ready for action.
As soon as you approach a velvet swimming crab will stand on its back legs, its claws raised, ready for battle.

There are plenty more dangerous creatures, such as the weever fish and the Portuguese man o’ war, that didn’t make our list because we so rarely see them in the rock pools.

It almost goes without saying that by far the most dangerous creature on the shore is us humans. Marine litter, warming seas, pollutants, overfishing and habitat destruction all threaten our amazing marine life. Please do your bit every time you visit the shore:

  • If you turn any rocks replace them gently, the right way up.
  • Avoid using nets that can harm creatures and tread carefully.
  • If you catch any creatures, keep them in plenty of sea water and return them quickly to where you found them.
  • Don’t leave any litter behind and be aware that sun cream isn’t good for wildlife.
  • Every time you visit a beach take 2 minutes to pick up any rubbish you see.

Have fun and please do let me know what creatures you meet (fierce or otherwise) in the Cornish rock pools.

Rockpooling at Hannafore – Video

A variegated scallop opens up showing its multiple eyes then snaps shut. A topknot flatfish skimming along the sand. Just some of the creatures I saw in the rockpools at Hannafore, Looe today on the low spring tide.

I was a too busy taking kids ‘shark hunting’ to take more video today. It was a successful mission; we found more than twenty live egg cases of the Nursehound (Scyliorhinus stellaris) and one live Smallspotted catshark (Scyliorhinus canicula) egg case. There were all sorts of other treasures too.

I’m already looking forward to doing it all again tomorrow.

 

Worms, slugs and jelly

As anyone who spends time around children knows, they generally delight in things that adults find yucky. So, what better for a day out with Cornish Rock Pools Junior than a visit to a sheltered, silty shore? It’s the perfect environment for all things slimy.

It didn’t take us long to find one of the strangest – and stinkiest – animals on the shore, the bootlace worm. We turned a stone and on one side was the head and part of the tangled body of the brown worm. The rest of the body spanned across to the next boulder like a rope bridge.

The thin, long body of a bootlace worm stretched between two rocks.
The long, thin body of a bootlace worm stretched between two rocks.

The bootlace worm is massively long – the longest recorded apparently came in at 55 metres, making it the longest animal in the Guinness Book of Records. This one would probably have spanned at least 7 metres. Given the difficulties of unravelling the tangled body without breaking it coupled with the fact it exudes acrid-smelling, toxic mucus, we decided against measuring it.

On another rock we found a prettier creature, the candy-stripe flat worm. This one had moulded its paper-thin body to the contours of the rock. When they’re not oozing along like this, they’re reasonable swimmers, albeit with a technique that resembles a tissue blowing along the pavement.

A small candy stripe flatworm oozing along its way.
A small candy stripe flatworm oozing along its way.

We started the search for jellies. The sheltered clumps of seaweed seemed a likely spot for stalked jellies, although Junior’s fascination with kicking up ‘pyroclastic flows’ of silt did hamper visibility a little. For a while we found nothing but ‘snotworm’ eggs, the green eggclumps of the green leaf worm.

When we did find our first jelly blob, it turned out to be another kiddy favourite, a slug. Out of the water, it was a shapeless splodge of yellow. In the water, it stretched out its white body to display yellow stripes and various yellow appendages and antennae.

Sea slug - Polycera quadrilineata
Sea slug – Polycera quadrilineata

As we watched the Polycera quadrilineata slug’s slow progress along the seaweed, we noticed another, more flowery jelly-blob behind it. This was the first of several Lucernariopsis cruxmelitensis stalked jellyfish we found.

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

The incoming current was throwing up a cloud of silt, but we managed to find eight stalked jellies among this small area of the shore. Not a bad haul of squidgy, slimy, child-pleasing creatures.

Stalked jellies have stinging tentacles like their cousins, the jellyfish, but live attached to seaweed rather than floating in the ocean.
Stalked jellies have stinging tentacles like their cousins, the jellyfish, but live attached to seaweed rather than floating in the ocean.

 Here are some of our other favourites from this expedition:

A sea spider. These delicate little creatures are perfectly camouflaged among the seaweed.
A sea spider. These delicate little creatures are perfectly camouflaged among the seaweed.
Tubulanus annulatus. This strikingly coloured worm was a first for me and is more commonly seen offshore.
Tubulanus annulatus. This strikingly coloured worm was a first for me and is more commonly seen offshore.
I was right at the depth-limit for my wellies when I found this topknot flat fish scooting along the bottom of a pool. Junior loves their asymmetrical faces.
I was right at the depth-limit for my wellies when I found this topknot flat fish scooting along the bottom of a pool. Junior loves their asymmetrical faces.
More slime! Cowries are able to dangle from the rocks using their strong mucus trails.
More slime! Cowries are able to dangle from the rocks using their strong mucus trails. This one’s in typical abseiling position.

Rockpooling on a mega-tide

This week the spring tides are huge, which means perfect rockpooling conditions all around Cornwall. Yesterday’s ‘storm without a name’ passed just in time and today the sun shone, so I dusted off my waders and followed the tide out to see what it would reveal. Answer: lobsters, baby sharks and a whole lot more.

Greater spotted catshark baby - Scylliorhinus stellatus
Greater spotted catshark baby – Scyliorhinus stellaris

I was hoping to re-discover an overhang packed with jewel anemones at the far end of the beach that I’d come across once before, but couldn’t resist taking a look at the wildlife on the way. You know it’s going to be a good day when the first stone you lift is unexpectedly awesome. This one was hiding a troop of hermit crabs, a rock goby and a beautifully camouflaged scorpion fish. Continue reading Rockpooling on a mega-tide

Egg hunting in the Cornish Rock Pools

It may seem too early in the year for rock pooling, but this is an exciting time of year on the shore. Spring has arrived in the Cornish rock pools and the huge clutch of eggs under the tail of a female green shore crab proves it.

Eggs come in all sorts of forms in the rock pools. Why not get out for your own ‘egg hunt’ on the shore this Easter?

Here’s my quick guide to some of the common types of egg you might see. Continue reading Egg hunting in the Cornish Rock Pools

Cornish Rock Pools visits Brittany – Honeycomb Worm Reef

My son loves the beach at Sainte Anne la Palud; wild dunes stretch towards a distant headland and the sand is perfect for building his creations. It’s why we return here at the end of our holiday in Brittany.

Ste Anne at low tide
The beach is vast at low tide

Last time we came it was a high spring tide and the beach was just a sliver of sand strewn with prickly cockles, sea potato urchins and even a dead eel. Now the sea is at its very lowest, a bare glimmer on the horizon. I walk towards distant low cliffs, expecting to find mussel beds around the exposed headland.

I should know by now that rock pooling can be surprising. Continue reading Cornish Rock Pools visits Brittany – Honeycomb Worm Reef