Category Archives: Rock pooling tips

Rock Pool Highlights in Looe

June 13, 2022 Heather Buttivant Leave a comment

As anyone who takes notice of the natural world knows, nothing stays the same. I visit my local beaches around East Looe so frequently that I know every rock and every pool. Yet, the more time I spend here, the more I notice.

Sitting by a pool for a long time, I notice more and more detail, like this tiny needle whelk.

Sometimes I learn something new about a familiar animal, sometimes I am treated to fascinating displays of natural behaviour, and sometimes I find species I never seen before. Here are five recent highlights from my local beach.

There’s always something new to see… in this case it’s Other Half in his new waders.

Cushion Star Hatchlings

It took me many years to realise that cushion stars lay eggs and to finally see my first just-hatched babies. Now I know what to look for, I see their eggs everywhere in the summer rock pools.

So many baby cushion starfish (Asterina gibbosa), fresh out of their eggs.

I find a cluster of new, tiny cushion stars and fall in love with their bright orange perfection and impossibly small tube feet.

Cushion stars – these baby starfish have just hatched and are setting out across the pool on their little tube feet.

A Hermit Crab Without a Shell

The thing that everyone knows about hermit crabs is that they live in the empty shell of a sea snail. It’s not entirely true to say that they have no shell of their own though. Hermit crabs have tough claws and shell covering the front part of their body. Just like other crustaceans, they moult their shell each time they grow.

A St Piran’s hermit crab, East Looe. This hermit crab’s rear end is comfortably housed in a shell.

Moulted shell of a St Piran’s hermit crab. Hermit crabs have shell covering the front part of their bodies. When they grow, they moult their old shell, leaving it behind.

Hermit crabs don’t, however, have a shell on their rear end. Instead, they have a long, spiral tail, which is soft and bendy. When the hermit crab finds a suitable shell to live in, it winds its tail up through the internal structure of the shell, clamping its home in place.

If a hermit crab loses its shell to another crab or a predator, it finds itself in a real predicament. That soft tail is vulnerable to attack.

Hermit crab out of its shell, showing its curly tail.

When Junior and I come across a homeless hermit, we locate a suitable empty shell and watch what the crab does.

The whole process is astonishingly quick.

Nudibranch Sea Slug – Eubranchus exiguus

Regular readers will be well aware of my (entirely justified) obsession with sea slugs. If you aren’t already aware of how exquisite these little animals are, you might like my introductory talk for The Shores of South Devon.

Most UK sea slugs are small and some are so tiny that you can barely see them with the naked eye. I spot a speck of jelly on some seaweed and spend the next twenty minutes crouching in the water to try to focus my camera on it.

*Eubranchus exiguus* – a nudibranch sea slug, Looe, Cornwall.

The slug is moving, the seaweed is moving and my hands are far from steady, but the photos are good enough. Meet a species of nudibranch sea slug that is new to me: Eubranchus exiguus.

*Eubranchus exiguus* sea slug, showing the distinctive shape of the cerata on the slug’s back.

The long, inflated cerata on the back of this sea slug look like they have been pinched in near the top, giving them a vase-like shape. Scattered white flecks adorn its body. When I can get it in focus, it is a fabulous-looking creature.

The Eubranchus exiguus slug on seaweed with my finger in the background to give an idea of scale. It was around 2mm long.

Rock Goby Eggs

There are few things more mesmerising than fish eggs. They are generally transparent, meaning that you can see the babies’ eyes looking out at you. As the fish grow, they become fidgety, twisting and turning inside the egg. Rock gobies are a very common rock pool fish and their distinctive capsule-shaped eggs are usually well-guarded by the father, who stays close until they hatch.

Doto slugs (and a bonus slug)

Finding sea creatures in the pools is a haphazard business; you can rarely be sure of finding even common species. However, if I want to find a Doto sp. slug, I know just where to look.

In places around my local rocks, the brown seaweeds (wracks) are so completely covered in hydroids that they look like they have grown beards. Very close-up, these hydroids (Dynamena pumila) look like stacks of pale triangles. Among them, feeding on the hydroids, are the tiniest splodges of jelly – the Doto slugs.

*Doto sp.* slug – possibly *Doto onusta*. Looe.

Out of the water, they are a sorry, squidgy mess. If, however, I can persuade one off the hydroid, I can put it in the water to reveal its towering jelly-mould structure decorated with charming crimson or black dots. The satellite dish rhinophores (antennae) on the slug’s head are an impressive accessory too.

*Doto sp*. slug – possibly *Doto onusta*. Looe, Cornwall.

Whether they remind you of cakes or jellies, there’s something gloriously edible-looking about the Doto slugs.

Warning: Slugs are not dessert. Don’t eat rock pool wildlife.

The little spots on the slug’s cerata look so much like cherries on a cake. *Doto sp.* slug, Looe.

It isn’t clear what species these slugs are; Doto slugs are notoriously difficult to identify. They were initially thought to be Doto coronata. That species isn’t now believed to feed on Dynamena pumila, so they may be a species known as Doto onusta – or something else. Whatever they are, I absolutely love to see them.

And now for a bonus slug… The orange-clubbed slug, Limacia clavigera, is a frequent find, but is too fabulous to be left out. Enjoy!

The orange-clubbed sea slug, *Limacia clavigera*. Looe, Cornwall.

Have you found anything new on your local beaches? I love to hear what other people have seen and can often help to identify unusual finds if you’d like to get in touch.

You can also find identification guides to some common rock pool creatures such as crabs, starfish and fish on my Wildlife page.

Whatever the weather, always stay safe in the rock pools. Follow my rockpooling tips to look after yourself and the wildlife on the shore.

This website is a labour of much love and the content is available for free to everyone. My wonderful readers often ask if there is a way to support my work. You can now ‘buy me a coffee’ through my Ko-fi.uk page. (Just click donate and you can set the amount to pay by PayPal). Thank you!

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Rock pooling tips, Wildlife

A Night Out In The Rock Pools

July 11, 2021 Heather Buttivant 4 Comments

It’s not often that you have the beach to yourself in Cornwall in July, but we want to show our friends the best Kernow has to offer. With this in mind, we meet Irys and her mum late in the evening to walk to our local shore and crunch across the sand to the rocks in the grey twilight.

Arriving at the empty beach before it is completely dark. (Photo by Other Half).

It doesn’t seem dark yet, but the birds are quiet, there are no other people about and it’s becoming hard to see where we’re putting our feet.

At night, it is especially important to put safety first so that you don’t find yourself in difficulty and have to get the Coastguard out of bed. We stick to a planned route on a beach we know well so that we will not be clambering over unfamiliar or slippery rocks. As always, an outgoing tide is safest and we arrive a full two hours before low tide so that we will leave before it turns. Sturdy boots and good torches are essential equipment, as are working phones and warm clothes. Our best-loved pieces of nighttime kit are our ultra-violet torches. Irys is trying hers out for the first time.

Testing the UV torch on some anemones. (Photo by Other Half)

The lack of predatory birds and drying sun makes life easier for rock pool inhabitants, so most of them are nocturnal. Creatures that we have to search for in daylight, such as prawns, crabs and fish, are all out and about looking for food.

Junior takes Irys straight to his favourite spot for seeing gem anemones. Under the UV torch they glow brightly, as does this snakelocks anemone. This fluorescence is caused by proteins that may help the anemone to survive in bright sunlight in shallow pools.

By scanning the torch across the pools it is possible to spot the anemones from some distance away.

Snakelocks anemones fluorescing. Seaweeds on the rock are also fluorescing red and pink.

We stand on the rocks and look into a large pool. Prawns, glowing blue under the UV torch, swim to and fro, intent on feeding. A common shrimp skitters across the sand. The green seaweeds glow bright red and the pink encrusting seaweed takes on a deeper pink-purple hue.

We alternate between the normal torches and UV, finding sea scorpion fish, a rockling and even a young tompot blenny with its distinctive headgear. Irys finds a common blenny in a hole in the rock, lying still and breathing through its skin while it waits for the tide to return.

Sea scorpion fish – Taurus bubalis – hiding among the seaweed.

Hermit crabs run around the pools and some of the top shells glow pink under UV where their shell has worn away to reveal the mother of pearl layer below.

Taking a close look at an isopod at night. (Photo by Other Half).

Flying insects swarm around our head torches while bats dance in and out of the light. We tread carefully and stop still for long periods, looking into the water, enjoying the window into the animals’ lives while the waves splash against the rocks beyond us.

It’s fascinating to explore fluorescence. Anemones glow, stalked jellyfish not so much. Crabs and isopods stand out against the seaweeds in shades of blue and grey. A shell containing a hermit crab shines a bright orangey-red, probably due to micro-algae growing on it. In every pool, once you get your eye in, there are countless blue specks zipping about in dizzying circles, which must be copepods or similar small crustaceans that I would normally only see under the microscope.

At night, crabs often emerge from the water and cross the rocks. This green shore crab was carrying a limpet off to eat.

Green shore crab holding a limpet in its right pincer.

Normally it is the rising tide that brings an end to our rockpooling, but tonight it is tiredness that creeps up on us. Still buzzing from all that we have seen, we head home to bed. Behind us the rock pools seem quiet and deserted, but we know better; for the wildlife on the beach, the night is just beginning.

Events, Rock pooling tips

May Half-Term Rock Pooling

May 25, 2021 Heather Buttivant 2 Comments

Who doesn’t need a week off at the moment? Whether you’re visiting your local beach or holidaying in Cornwall, rock pooling is a free and fun experience for all the family.

Read on for links to events, rock pooling tips and my guide to what you might find.

Make every beach trip an adventure with my children’s book, Beach Explorer: 50 Things to See and Discover. It’s packed with hands-on activities, facts and quizzes.

EVENTS

Organised rock pooling events are perfect for learning about marine wildlife with the experts. Due to current restrictions, booking is essential for most activities and plans may change. At the time of writing, the following groups and organisations are planning events in the half term:

If you’re not able to attend an event, don’t worry. It’s easy to rock pool safely and to look after the wildlife with a little preparation.

ROCK POOLING TIPS

All you need for successful rock pooling is a pair of wellies or sturdy shoes and a little patience. There are many fascinating species to see, so go slowly, look carefully, leave everything as you found it and have fun!

The European 3-spot cowrie (Trivia monacha)
St Piran’s Hermit Crab at Hannafore, Looe
A colourful Xantho pilipes crab.
A dahlia anemone.
Watching fish at Kynance Cove
Green shore urchin, Hannafore, Looe
Learning about a spiny starfish at a Wildlife Watch event
Junior getting to know our wrasse-friend before we put it back
A juvenile turbot at Lundy Bay
Drying off in the sunshine after rock pooling at Port Nadler, near Looe.
Plaidy near Looe
Just one more rock… exploring the Cornish rock pools
Flat periwinkles and other shells washed up on Looe Beach
Montagu’s blenny with its distinctive head crest
Painted top shell.

Always check the tide times, stay clear of cliffs and waves and dress for the weather.
Nets can harm delicate sea creatures so are best left at home. A bucket or tub is ideal if you want to scoop up an animal to look at, but be sure to put it back.
Why not finish up with a beach clean to help look after the wildlife?

Find out more about rock pooling with my top tips and guides.

BEACHES

The choice is endless! Cornwall has over 300 beaches and they are all fantastic. Any beach with rock pools will have crabs, snails, anemones, fish and more.

Find out about some of my favourite rock pooling beaches here.

WHAT TO SEE

May and June are fabulous rock pooling months. The pools are bursting with new life from baby fish to brightly coloured seaweeds and stunning starfish.

Sit quietly and look closely at the pools to watch prawns, crabs and sea snails going about their business. Gently lift seaweed and look under stones to reveal the secret hiding places underneath (be sure to put them back as you found them).

Here are some of my favourite treasures to find in the pools …

Cushion Stars

**These puffy little starfish are common in the pools. Did you know that they can re-grow their arms?**

Shannies

The common blenny (or shanny) is perfectly adapted to shore life and can even breathe through its skin when out of the water. It also has a great smile. — **The common blenny (or shanny) is perfectly adapted to shore life and can even breathe through its skin when out of the water. It also has a goofy smile.**

Sea lemons

Green Shore Crabs

Green shore crab with eggs - Christmas eve 2018 in Looe — **Green shore crabs can survive in lots of different conditions and can eat almost anything – even each other. This female has eggs under her tail.**

Common Prawns

**Prawns are curious and will often swim over to investigate anything new in their pool. You can see right through their bodies!**

Strawberry anemones

Star Ascidians

Flat Periwinkles

Flat periwinkle in the Cornish rock pools — **Flat periwinkles feed on seaweed and come in lots of colours. Look out for their eggs on the seaweed – they look like little circles of jelly.**

These are just a few of the creatures you might find. Discover more with my guides to the wildlife in the rock pools and my blog.

Happy rock pooling! Be sure to get in touch to let me know what you find this half-term.

Rock pooling tips, Wildlife

Rock Pool Bingo – Searching for Southerly Species (Part 1)

August 13, 2019 Heather Buttivant 5 Comments

It’s always wonderful to spend time with other rock pooling obsessives, so I was popping with excitement at the prospect of three whole days one the shore with friends from North Wales.

Welsh coasts are wonderfully rich in marine life, but I was looking forward to showing my friends some species that I see in Cornwall which aren’t found in most of the rest of the British Isles. I also had a new camera to try out. We wasted no time in drawing up a bingo card of what we hoped to find.

On day 1 we explored the shore at Hannafore in Looe. Junior knew exactly where to look to cross off the first species on our bingo card: the St Piran’s hermit crab (Clibanarius erythropus). He scrambled over rocks on the mid-shore to a pool where these crabs tend to congregate and within a minute he had located the first one.

Sometimes these hermit crabs, with their red antennae and equal-sized claws are barely visible, hiding deep in their borrowed shells. Today they were less shy. This one seemed to almost fall out of its shell as it investigated my camera, while another nipped boldly at my friend’s fingers as he photographed the crab’s distinctive black and white chequerboard eyes.

St Piran's crab almost out of its shell, showing its short back legs — St Piran’s crab almost out of its shell, showing its short back legs

As we followed the tide further down the shore, we looked for sea slugs in some of the usual places but with no luck. I soon realised that I was the only one feeling disappointed. With his head hidden from sight under an overhang, one of my friends was gasping in delight at the sight of a painted top shell. They might be common on the shore here, but apparently that’s not the case in Anglesey.

Although painted topshells are a common sight on my local shores, I never tire of photographing them.

Despite the keen breeze that was preventing the tide running out as much as I’d hoped, we soon ticked off another item from the wish list.

I’ll admit that I hadn’t realised that rainbow wrack (Cystoseira tamariscifolia) is mainly a south westerly species. This bushy seaweed is one of our most unmistakeable plants and is a common sight all around Cornwall. In the water its fronds display a turquoise-green iridescent sheen that is arrestingly beautiful. Out of the water, rainbow wrack loses its magic, appearing brown or dull-green. For some reason I find it impossible to fully capture the colours in photos.

Rainbow wrack - a southerly species on our 'bingo card'. — Rainbow wrack – a southerly species on our ‘bingo card’.

Catsharks favour rainbow wrack when they come inshore to lay their distinctive egg cases often known as “mermaid’s purses”. Despite my hopes of ticking off the egg cases of the greater spotted catshark (Scyliorhinus stellaris) on day 1, the breezy conditions meant we struggled to see into the water. The only eggcases I found were from the smaller species (Scyliorhinus canicula).

A small-spotted catshark eggcase with a baby shark starting to develop inside.

The small patch of seagrass that appeared last year was looking denser and wider than before. The length and width of the fronds suggested that it might be Dwarf seagrass (Zostera noltii), a different species from the other seagrass bed I know of on the site.

The seagrass on this part of the site looked like it might be Zostera noltii, the dwarf eelgrass.

We embarked on the usual fruitless look for seahorses, which like to live in or near seagrass. I know they’re unlikely to turn up on the shore, but it never stops me looking.

With two species of stalked jellyfish on our bingo card, I was feeling confident of finding them. Instead I kept finding a species that my visitors had already seen, Calvadosia campanulata. These lovely bell-shaped jellies often have brilliant turquoise spots on the bell and and are very photogenic.

Turquoise spots on the bell of a stalked jellyfish (Calvadosia campanulata).

Despite the less-than-perfect conditions, we had ticked off some new species and amassed a huge collection of photos by the time the tide turned. With two days still to go and better weather on the way, we were off to an excellent start.

Blue-rayed limpet on kelp at Hannafore, Looe

Junior knew to look for photosynthesising sea slugs on codium seaweed. He found us this lovely solar powered slug, Elysia viridis.

A carpet of yellow star ascidian (Botryllus schlosseri) at Hannafore, Looe

One of the strangest finds of the day. Green shore urchins often camouflage themselfs with bits of seaweed or small pieces of gravel, but this one had completely barricaded itself in with chunky stones.

A bright-coloured pheasant shell at Hannafore, West Looe.

Anemones and Jellyfish, Rock pooling tips

A Night Out in the Rock Pools

May 19, 2018 Heather Buttivant 6 Comments

Nights out tend to become a distant memory when you’re a parent. For the most part I don’t miss them. I have, however, been looking forward to Junior being old enough to join me for night time rock pooling. Towards the end of last year, we tried it for the first time and, although the conditions weren’t ideal, he’s been asking to go again ever since.

The best low tides always happen around the middle of the day, and the middle of the night, but we compromise for this first family expedition of the year, choosing a reasonable low tide at around 10.30pm. The warm, calm weather provides good opportunities for seeing nocturnal activity and tonight I’m trying out my ultraviolet (UV) torch.

It doesn’t disappoint.

Head torch at the ready - night time rock pooling is a perfect adventure — Head torch at the ready – night time rock pooling is a perfect adventure

I’ve always known that certain species glow under UV light, but I had no idea how much. We’ve barely taken ten paces out across the rocks when we see our first snakelocks anemone, shining from the darkness like an eerie green beacon. The colour is wonderfully alien.

Snakelocks anemone at night under UV light - a true alien of the Cornish rock pools — Snakelocks anemone at night under UV light – a true alien of the Cornish rock pools

This fluorescence is caused by certain proteins within the animals that take in light of one colour and emit it as another. Some deeper water species can use these properties to appear red, even though red light is filtered out as it passes through the water, meaning the only light available to underwater creatures is UV or blue.

It’s not clear why snakelocks anemones and other sea creatures might want to fluoresce in this way. It seems there may be some benefit in it for their symbiotic algae or it might give them sun protection. It may just be a by-product of a protein that’s useful in other ways. Whatever the reasons, it produces an incredible glow. Junior is already talking of coming back at Halloween.

A spooky night time rock pooling walk is definitely on the programme for this Halloweeen! — A spooky night-time rock pooling walk is definitely on the programme for this Halloweeen!

It’s not just the anemones that take our breath away. If you’re used to rock pooling in daylight when most animals are hiding away under rocks and seaweed, the sheer level of activity in after dark takes you by surprise.

A scratching, crackling sound stops us in our tracks. It’s coming from the rocks. I lift the seaweed to show Junior a group of limpets. Some are feeding, their strong radulas scouring seaweed off the rock and chipping bits of rock. Others are setting into their home scars, grinding their shells into their grooves to create a perfect fit. Close-up, their activities make a surprising amount of noise.

Limpets on their way home as the tide retreats

Most rockpool animals are largely nocturnal. Pools that seem empty in daytime become bustling cities of activity. We watch hermit crabs milling around in large numbers, crabs marauding through the pool and across the rocks, fish floating in plain sight. Prawns come towards the light and watch us before shooting away backwards.

A green shore crab looking blue in the UV light

Hermit crabs are more active at night, every pool is teeming with them

Other Half spots a small species of spider crab (Macropodia sp.) decorated with long fronds of seaweed edging sideways across the pool. It’s moving too fast to take a clear photo in the poor light. The blurring makes it look even more alien.

A blurry small spider crab (Macropodia sp) moving across sand.

A scorpion fish lies still on the sand, watching out for prey.

A scorpion fish (Taurus bubalis) hiding in plain sight.

One surprise is the stunning colours of the seaweeds under the UV light. Some of the dark red seaweeds take on a far more intense, bright colour, glowing red, pink and orange. Where the top shells have worn spires, their tips glow pink.

A grey topshell on a red seaweed under UV light

After an hour, tiredness and cold begin to set in. We switch off our torches and take a moment to gaze at the stars before we head home to bed. Junior is already asking if we can come again the next night, and the next.

It looks like I’ll be having a few more nights out this summer.

Rock pooling tips, Wildlife

Fifteen Minute Rockpool Challenge (and some mutants)

March 17, 2018 Heather Buttivant Leave a comment

I’m not sure who cancelled spring, but I’m not impressed. Yet again, the spring tides are accompanied by ear-numbing winds and a flurry of snow. Just the thought of plunging my hands into the pools makes my fingers ache, and yet, like the fool I am, I wade into the pools to see what’s there.

Due to my reluctance to leave my warm house, it’s half-past low tide by the time I hit the beach. The easterly winds are dashing the waves against the rocks and the gully I’d hoped to explore is well and truly submerged. All that’s left is an average-looking pool.

My average-looking pool for the 15 minute challenge

I’m tempted to give up and go home, but I’m always telling people that there’s something in every pool. That you just need to go slowly and look closely. I set myself a 15 minute challenge to find as many species as I can.

One of my first discoveries is this wonderful mutant cushion star. According to the books, these have five arms. Clearly this one hasn’t read the books. At some point it has lost one or more of its arms and in an incredible feat of regeneration it has sprouted an excess of new ones.

A Cushion star trying to pass as a seven-arm starfish. — A Cushion star trying to pass as a Seven-arm starfish.

In fact, this cushion star has put so much energy into sprouting arms that it now has a total of seven arms. I do sometimes see another species, the Seven-armed starfish, but they are bright orange and have longer arms so I’m not fooled. It’s a nice try though.

There are lots of molluscs including several colourful painted topshells.

Nearby, a colony of dog whelks huddles in a crack in the rock, around their yellow egg capsules.

A colony of dog whelks with their yellow egg capsules

It’s hard to see through the wind-rippled water into the tangled seaweed below, but this Calvadosia campanulata stalked jellyfish catches my eye. Its bright-white stinging cells stand out among the pink and red seaweed fronds.

Calvadosia cruxmelitensis stalked jellyfish

There are several more stalked jellies, including this Haliclystus octoradiatus. This species has a blob between each pair of arms, which acts as a sucker (‘primary tentacle’) allowing the jelly to flip upside down and cartwheel along the seaweed. This one seems to have two suckers between some of its arms. It also has an extra arm (nine arms instead of 8).

I start to wonder if this pool is going to be full of mutants with extra arms and tentacles.

Another mutant - a nine-armed Haliclystus octoradiatus stalked jellyfish with some extra primary tentacles. — Another mutant – a nine-armed Haliclystus octoradiatus stalked jellyfish with some extra primary tentacles.

The waves are breaking over the rocks and splashing over my back and the water level is rising precariously close to the top of my wellies. I take a few more quick photos of some wriggling worms, strawberry anemones and a banded chink shell just a few millimetres long.

As I leave the pool, I find a Saddle oyster shell. These small oysters attach to the underside of rocks and have round hole in the upper valve.

Inside of a saddle oyster shell showing its incredible mother-of-pearl colours

It may be a grey day, but the inside of the shell is coated in the most brilliant mother-of-pearl, shining with every colour of the rainbow. I’ll take it as a sign that spring’s on its way.

Rock pooling tips

Spooky Rock Pool Spells

October 29, 2017 Heather Buttivant 3 Comments

Cornish Rock Pools Junior loves Harry Potter. A while back he noticed that a lot of rock pool creatures have scientific names that sound like spells straight from a Hogwarts classroom.

Rock pool animals have many amazing (and disgusting) tricks up their sleeves. Some are simply fearsome looking like the Devil crab in the photo above. Others have weapons and disguises.

What better way to learn their names than by chanting them spell-style to unleash their freaky abilities?

So, wands at the ready – swish and flick – here are some top spooky rock pool spells.

Sepia officinalis – Invisibility spell

A cuttlefish shows off its camouflage skills in the IFREMER visitor centre, Concarneau, Brittany.

Nothing can hide better than a Common cuttlefish. Sepia officianalis can change colour and texture in an instant to make it invisible to both its predators and its prey.

Marthasterias glacialis – Regrow-an-arm spell

This Spiny starfish (Marthasterias glacialis) is regrowing two of its arms.

Many sea creatures like crabs and starfish can re-grow a lost limb. Starfish like this Spiny starfish can regenerate several arms at once, so it’s not uncommon to find one with just a couple of arms and three stumps.

Here’s a spooky story for you… Some say that fishermen in the North Sea used to hack starfish in half when they found them in their nets. Starfish attacked their catch so they were determined to get rid of them. They slaughtered all the starfish they could get their hands on, certain they were reducing the population. Instead, each half of the severed starfish began to regenerate, slowly regrowing its arms. So, every time the fishermen cut one in half, they created two starfish. Soon the area was swarming with starfish.

I’m not convinced this story’s true, but it makes a great Halloween tale!

Berthella plumula – Acid squirting spell

More dangerous than it looks - the Berthella plumula sea slug — More dangerous than it looks – the Berthella plumula sea slug

Lots of sea slugs use poisons from their prey to defend themselves and some produce acid. The Berthella plumula can squirt out sulphuric acid from a special gland when it’s attacked. If you pick one up, it’ll make your skin blister and fall off (so best not to!).

Anemonia viridis – Harpoon stinging spell

The tentacles of the Snakelocks anemone are packed with harpoon-like stinging cells

Use this spell to unleash a secret weapon – the nematocysts. All jellyfish, anemones and other related animals have special stinging cells called nematocysts. Inside each cell is a coiled harpoon, which is fired out into anything that touches the tentacles.

Here’s a video of a pool full of Anemonia viridis eating an unfortunate fly.

Lineus longissimus – Smelly slime spell

Part of a Bootlace worm on a rock - if you pick it up you'll get stinky slime on your hands. — A Bootlace worm on a rock – if you pick it up you’ll get stinky slime on your hands.

The bootlace worm is in the Guinness Book of Records as the world’s longest animal. When fully unravelled it often stretches 7 or 8 metres but the longest ever recorded was an incredible 55 metres long. More importantly, though, its special power is giving out a stinky slime. A perfect spell to use against your enemies!

Elysia viridis – Energy-making spell

The photosynthesising sea slug - Elysia viridis, grazing on Codium tomentosum seaweed. — The photosynthesising sea slug – Elysia viridis, grazing on Codium tomentosum seaweed.

Feeling worn out? Try the Elysia viridis spell instead of over-doing the trick-or-treat sweets. This amazing little sea slug retains energy-making chloroplasts from the seaweed it eats. The chloroplasts carry on making food for the slug through photosynthesis, giving the slug an ideal energy boost.

Aplysia punctata – Smoke screen spell

We must have accidentally disturbed a sea hare (Aplysia punctata), making it release a cloud of purple ink.

Werewolves, zombies and vampires on your tail? Don’t panic – use the smoke screen spell!

Sea hares (Aplysia punctata) may look like dull brown blobs, but they are as strange as rock pool creatures get. Not only do they lay eggs in the form of pink silly-string, but they have the ability to shoot out a cloud of purple ink when attacked, providing a perfect smoke screen.

These are just a few of the bizarre things our rock-pool creatures can do. There’s plenty more rock pool magic to learn.

If you’d like to know more about the gruesome habits of the animals on our shore, have a read of my guide to revolting rockpools. You can also take part in organised events to meet the creatures for yourself. Happy Halloween!

Anemones and Jellyfish, Crabs, prawns and lobsters, Rock pooling tips

Top 5 Fierce(ish) Rockpool Creatures

May 5, 2016 Heather Buttivant Leave a comment

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)

OLYMPUS DIGITAL CAMERA — 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.

Rock pooling tips, Wildlife

Warm in Waders -a chilly beach adventure

April 17, 2016 Heather Buttivant 4 Comments

Have I mentioned that I don’t like the cold? Well I don’t, and worse than that I don’t function well in it; my fingers seize up, my brain goes fuzzy and my grumpiness level soars. Not ideal when I’ve agreed to meet up with a small army of children on a freezing, windswept beach. Fortunately I’m prepared and have no shame.

Full thermals + three layers of jumpers + coat + scarf + green waders equals = a toasty-warm fashion disaster.

Junior’s still young enough not to notice or care about anything except whether I’ve brought his enormous metal spade. The other kids don’t seem worried either as I waddle over to them. They call me ‘the shark lady’. I think they mean that in a good way.

It’s amazing how fast children learn. A few minutes after he’s shown his first catshark egg case, a friend’s child is spotting them everywhere, his sharp eyes picking them out faster than me. We’ve soon clocked a couple of dozen of them. The parents find some too.

Mandy's catshark egg case. Hannafore, Looe — Mandy’s Greater spotted catshark egg case. Hannafore, Looe

Continue reading Warm in Waders -a chilly beach adventure →

Rock pooling tips, Wildlife

A rockpooling warm-up

April 7, 2016 Heather Buttivant 4 Comments

You might not think that rockpooling is the sort of activity that requires a warm up, but there’s nothing like practice for getting your ‘eye in’. The more and closer you look, the more you’ll see. What better excuse to get out on Cornwall’s beaches before, during and after this week’s massive tides?

I’ve been out on a few family rambles on the local shores the last couple of weeks to make sure I’m ready for some serious rockpooling this weekend (like most weeks, but they don’t complain).

If you’re wondering what you might see if you head down to the shore in the next few days, here are some of the things I’ve been finding…