Tag Archives: Looe

paddle–swimming And fish-whispering: Summer rock pooling in Cornwall

The sun is back and, for once, it has coincided with some big tides. Beach shoes at the ready, Junior and I scramble across the rocks, the clamour of the busy beaches far behind us, heading for our local pools. With Covid levels higher than ever in Cornwall at the moment, we’re hiding away from the crowds as much as we can.

The view to Downderry from East Looe.

We are so used to having to put on layers, waterproofs and wellies that it feels quite decadent to be able to wander about comfortably in shorts. The water is sparkling and the sun’s reflection on my camera screen is so strong that I can’t see the image properly, even when I adjust it to maximum brightness.

I might not be able to see much at first, but the pools are full of life. We cross the rocks to a wide pool fringed with oarweed and sugar kelp. We slip and slide over thongweed and step carefully into the cool water to avoid disturbing the wildlife.

Gorgeous blue-rayed limpets are everywhere on the kelp.

A small movement reveals the presence of a well-camouflaged dragonet. Knowing how hard it is for anyone to detect it, the fish takes its time, gliding a short distance across the sand then taking a break, seeming to disappear each time it stops.

The dragonet blends in perfectly with the sand, pebbles and shells.

Among the delicate red seaweeds, there are plenty of stalked jellyfish (Haliclystus octoradiatus). Their colour range is the same as that of the seaweeds, so although they are bright and attractive, they are not easy to spot.

Stalked jellyfish: Haliclystus octoradiatus

With every step I am getting deeper into the pool, but for once it doesn’t matter. Soon I am right in the middle, with water lapping up to my waist. A blue dragonfly zigzags past me, swooping low before turning back and disappearing towards the cliff.

I wade over to a tall rocky overhang while Junior enjoys a swim across the pool. There are several large fish flitting in and out of the kelp so I lower my camera a little at a time to see how they react. When this is successful, I decide to make the very best of the summer conditions. I pull my swim goggles on and lower my head into the water.

The fish (juvenile pollock) are stand-offish at first

There is a nursery shoal of juvenile pollock down here.  They hesitate at first. Winding their slender bodies through the kelp fronds, they watch me through wide yellow-rimmed eyes.

The young pollock get ever closer to take a look at me.

I’ve always thought of pollock as a silver coloured fish, but these youngsters are golden-green with shimmering blue stripes running from their head to their tail. Their jutting bottom lip makes them look open-mouthed, mid-conversation.

Hello fish friends! The young pollock are keen to take a close look at my camera.

They are certainly a friendly bunch, swimming ever closer to the camera until their tails are brushing the lens. I have to keep lifting my head to breathe, but they don’t seem to mind.

Video: Hello fish!

After a while, I leave the pollock to talk among themselves and move on to an adjoining pool. A shoal of sand eels is patrolling here. These fish are of a more nervous disposition, turning, balling and flashing with silver at the slightest disturbance. If they spotted a predator, they would flee head-downwards, burying themselves in the sand in an instant.

Sand eel swim-past.

I move slowly and give the sand eels space, turning my attention to the sea squirts and snails on the rocks.

An especially pretty yellow star-ascidian surrounded by pink algae and red seaweeds.

When the tide turns, Junior and I retreat to the first pool, swimming and bobbing in the water, watching butterflies tumble past and swallows circling high above. There are boats, people and a whole world out there, but, like the pollock, we are happy in our rock pool refuge.

Even the seaweeds are shining in the sun. Forkweed, Looe, Cornwall.

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


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Staycation Safari

After many days of getting drenched every time we step outside, Junior and I decide to make the most of the warmer weather and have a lazy day pootling about our local area. If everyone else is taking a holiday in Cornwall, so can we! The rocks between Plaidy and Millendreath are perfect for clambering and exploring, and I promise Junior a spot of wave jumping when we reach the sand beyond.

‘Slug alley’ at Millendreath

“I’ve found a blob,” Junior calls over to me.

I am kneeling among some seaweed at the top of a deep rocky gully. My head is almost pressed against the minute Dynamene pumila hydroids that grow on this seaweed, looking at what I’m sure is Doto sea slug spawn. “What kind of blob?” I ask.

“I think it’s a slug,” he says, and I’m up and at his side in a second.

The blob is bigger than I expect, almost like a small anemone on the rock. We stare at it closely, our heads touching. It looks as though it is tipped with blue.

“Oh my word,” I say. “I think you’ve done it.”

We hug and cheer and do a little slug dance, because every slug deserves a dance and this one is especially special. For weeks now, we have been looking for Antiopella cristata, a slug which ought to be found here but which I have never seen.

Taking great care not to harm the slug, we transfer it to a pot of seawater and watch it floof up.

The fully ‘floofed’ Antiopella cristata nudibranch sea slug.

The slug’s body is yellowish, but its back is covered in large waving cerata, each tipped in pale, frosted blue. The effect is like opening a geode to find tall, pointed blue crystals inside.

Close-up Antiopella cristata’s cerata remind me of peacock feathers.

We call the slug ‘Aunty Crystal’ to help remember its scientific name.

Antiopella cristata – or Aunty Crystal as we named this stunning sea slug.

We have named this gully ‘slug alley’ for a reason and plenty more creatures, slugs and others, are hiding on the tall, shady rock face. I find several bright red Rostanga rubra slugs munching on the red sponges.

The Rostranga rubra slug, which gets its incredible colour from the sponges it eats.

A tiny ghost-white slug has been laying its eggs nearby. In the water it takes on a frilly appearance, making it look ever more spectral.

Goniodoris nodosa, looking frilly and ghost-like.

Sea cucumbers adore this area and are to be found everywhere, with their bodies hidden in holes in the rock and just their black and yellow mouths protruding. The two main species I see are Pawsonia saxicola and Aslia lefevrei.

Sea cucumber at Millendreath.

When submerged, they will open a wide fuzz of frilly tentacles to feed.

We clamber over the rocks onto the sand, helping a stranded rockling back into a pool on the way, and splash in the waves for a while.

This rockling had ended up out of the water at low tide, so we helped it back into a pool.

A couple of shells roll past my feet, tumbled by the waves over the silty sand. I make a quick grab for them and, sure enough, they both contain hermit crabs. At low tide, I occasionally find this species here, easily recognised by its enormously long left claw. These crabs are both south-clawed hermit crabs, also known by their gladiatorial sounding scientific name, Diogenes pugilator.

Diogenes pugilator, the south-clawed hermit crab.

They are ready for battle, almost falling out their shells in their attempts to dislodge my grip, unaware that I am saving them from the herring gulls that are lurking at the water’s edge.

The south-clawed hermit crab has long hairs on its antennae.

Junior and I kneel at the edge of a sandy pool and pop the hermit crabs in. We watch one emerge without hesitation. The tips of its claws come first, then the stalked eyes and finally its long hairy antennae. The hermit crab hoists its shell up and runs a few paces.

With a furtive glance about it, the crab swings its vast left claw inwards, shoveling sand into a pile while simultaneously flicking the sand over its back with its little right claw. Grains of sand are flung up through the water and by the time they have settled, only the back of the shell and the tops of the hermit crab’s eyes are visible. It is buried out of sight.

We take the hermit crabs back to the sea, leave them as far out as possible – safe from predators – and carry on wave hopping until the tide turns, when we too must head for home.

Here’s a little video of this week’s highlights from the Cornish rock pools. Sit back and enjoy!

If you would like to find out more about rock pool wildlife or go on your own rock pooling adventures, be sure to pick up my books Rock Pool and Beach Explorer. Out now with September Publishing and available from all book shops and online.

Meeting up and staying apart in the rock pools

When I’m sitting here writing my blog in the evening, with the cat snoring gently beside me, I find it hard to imagine that people anywhere in the world might be reading about my finds the next day. So, it’s always lovely to receive messages from people who follow the blog and share my passion for our rock pool wildlife. It’s especially surprising to me that these include many people I’ve never met and that some of my readers even live beyond the Tamar!

With the days beginning to draw in and with all normal group activities off due to Covid, making connections with others is more important than ever. When I heard from a couple of keen naturalists and Shoresearchers planning a trip to Cornwall, I thought it could be fun to head out on the shore together with my family. I couldn’t have been more right!

You know someone is a good person when they like finding slugs. Within minutes of meeting our new friends on Millendreath beach near Looe, we had established that slugs were top of their wishlist of things to find. I led the way to “slug alley”, a deep gully between the rocks where I often find sea slugs feeding on the sponges, squirts, bryozoans and hydroids that line the dripping overhangs.

We advance in our family groups, keeping several metres apart, pointing at interesting creatures, giving directions then backing away. By this stage in the pandemic, we’re all confident in these new dance steps.

Botryllus leachii colonial sea squirts

Large patches of colonial sea squirts smooth over the rocky surfaces, providing not just striking colours and patterns but food for many animals that predate them. We find both the European three-spot cowrie and the Arctic cowrie happily gorging themselves on this beautiful feast.

A cowrie on the search for sea squirts to eat.

A brown spot among the squirts and barnacles catches my eye. Although the colours blend in perfectly, it looks different from its surrounds. I gently touch it and it comes away. In a seawater-filled petri dish it rapidly transforms itself, puffing up, elongating and sprouting feathery gills and tall rhinophores. There’s no doubt about it, we have our first slug. My excitement is as great as that of our new friends – this is a species I have never seen before.

Goniodoris castanea exploring the petri dish.

We take turns to examine the slug and take photos. As soon as it is under my camera, which shows far more detail than I can make out with the naked eye, I recognise it from my books (yes, I browse slug books for fun). It’s my first Goniodoris castanea. Castanea means chestnut and the slug’s autumnal mottling of red, brown and white hues make seems a perfect fit with the oncoming season.

Goniodoris castanea showing off its beautiful autumnal colours.
Goniodoris castanea

While our friends marvel at the slug, Junior makes another exciting find. He knows what it is just by the purplish tips of the arms protruding from under the rock. “Spiny starfish!” he calls. We carefully move it out to take a look and it’s a monster. Our starfish has clearly found plenty to eat in this area. Although we regularly see them on the shore here, spiny starfish aren’t found in rockpools in some other parts of the country and this is another new species for our visitors.

I forgot to take photos of the spiny starfish due to my excitement over the slugs – but here’s a pic of one we found on an earlier expedition to Millendreath.

We edge ever outwards with the tide. Although we can hear the shouts of holidaymakers playing in the waves on the beach beyond the rocks, no one else ventures into our magical gully where startled sand eels zip across the surface of the water like skimming stones and velvet swimming crabs scuttle across the seabed then bury themselves in the sand, leaving only their red eyes visible.

A lurking velvet swimming crab.

Some of the rocks are fringed with a dense covering of brown seaweeds. Toothed wrack and kelp compete for space here and clinging to this forest, mossy bryozoans and delicate hydroids thrive, creating a perfect habitat for isopods and slugs. Some of the seaweeds have crescents of white jelly scattered among their fronds. These are sea slug eggs but it takes me some time to find the slug itself, which is smaller than its spawn and decorated with bright yellow and black which somehow make it hard to see.

Sea slug spawn…. now to find the slugs.

These pretty little slugs were, until very recently, known as Polycera quadrilineata. Scientists have now discovered that there are two separate species and the ones we see here, which sometimes have black lines and spots, are now called Polycera norvegica.

Polycera norvegica feeding on bryozoans.

In the moving seaweed, it’s hard to take clear photos and the tide is, of course, coming in just as I’m trying to position the camera in water that’s already waist deep, but we are all content just to be here, together but apart, sharing this experience of encountering incredible creatures.

Polycera norvegica.
Pair of Polycera norvegica sea slugs with the edge of a fingernail in shot showing just how tiny these stunning little creatures are!

These are strange times for everyone, but finding ways to come together and enjoy nature is what makes the world go round (for me at least). Thanks to our new friends for making it a fabulous day. Happy rock pooling!

This time of year, the kelp is studded with blue-rayed limpets – always a joy to see.
Brown sea cucumber – Aslia lefevrei.

What to do when Rock pooling is cancelled? Go anyway!

After weeks of storms, the Looe Marine Conservation Group was hoping for a break in the weather for their half-term family rock pool ramble. Unfortunately the Cornish weather had other plans. With gusty winds delivering pulses of the sort of ‘light’ rain that soaks you in seconds, LMCG did the sensible thing and cancelled.

Meanwhile back at Cornish Rock Pools HQ, Junior already had several jumpers, three sets of socks and full waterproofs on and was ready to set off. Some of his friends were also set to join us on Hannafore beach. So, we ignored the cancellation, put our hoods up and set off.

Scooping up another hardy family on our way down the shore, we picked our way down to some gullies sheltered from the wind by large rocks.

“A fish,” Junior shouted. “I don’t know what it is. It looks like a tadpole.”

I made my way over to where the children were gathered.

“I think it might be a clingfish,” Junior explained.

The small dark blob was certainly suckering onto a stone. It was lying very still with its tapering tail curled around its wide head, hoping that it was well enough camouflaged that we couldn’t see it.

Bizarrely, this little fish is known as a Montagu’s sea snail. It has tiny eyes compared to the size of its head and with its fins tucked tight to its body, it does look rather like a tadpole. Under its belly, the fins have evolved to create a sucker that it can use to hold onto rocks, making it ideally suited to life around the shore.

Montagu’s sea snail (Liparis montagui) – a fish despite the name.

Montagu’s sea snails vary enormously in their patterning but have an unmistakeable shape.

In a nearby rock pool I found a group of young Xantho pilipes crabs sheltering under a boulder. These crabs have dense hairs around their back legs and thick-set claws, but their colour varies a lot. This one caught my eye as it was especially beautiful.

A brightly-patterned Xantho pilipes crab.

Most of the dead-looking crabs we find on the beach are empty moults, left behind by a crab that has grown out of its shell. I could tell straight away that this one had not been so lucky.

Dead Xantho pilipes crab being picked clean by Netted dog whelks.

Netted dog whelks are the vultures of the rocky shore. Equipped with long siphons that look like vacuum cleaner attachments, they spend their lives sifting through the sand and hoovering up any dead creatures. When something large like a crab dies, they can scent the food and quickly home in.

Unpleasant though it looks, scavengers play a vital role in any ecosystem, quickly and efficiently breaking down decaying matter. The children had a fascinating time watching the netted dog whelks at work. They wre moving surprisingly quickly, spinning their shells from side to side as they edged into spaces and were clearly competing to get at the best bits of food.

Before long the children had made lots of other finds. Among the tubs were several hermit crabs that had been given names. Junior adopted a lugworm that he found under a large stone and spent a long time watching and trying to photograph it. These worms make burrows in the sand and have a wide circular mouth that gapes open to swallow sediment, from which they filter out their food.

Lugworm with mouth open – photo by Cornish Rock Pools Junior
Junior’s lugworm

The rain had died down over the course of the morning and no-one was rushing to leave. So, after we had carefully said goodbye to all of the animals that the children had been caring for in their tubs, we took a last look around between the rocks.

As always there were plenty of treasures to be found and before long, the tide was turning and lunch was calling.

Green shore urchin.
Long spined sea scorpion
Bootlace worm – these worms are usually several metres long if fully extended but are always quite tangled!
Pheasant shell
Shore rockling (5 bearded) with a hemit crab and a prawn photobombing in the foreground.
Long-clawed porcelain crab
Another prettily patterned juvenile Xannto pilipes crab.

The Looe Marine Conservation Group run rock pooling events during every school holiday through the year and these are only rarely cancelled. There are similar groups all around Cornwall, and some across the border in Devon too. Look out for events near you!

A Quick Winter Walk

Though there is much to love about December, I know I’m not the only one who’s flagging well before the end of the month. The spring tides arrive at the perfect time to boost my energy levels, ready for all the rockpooling and writing adventures that await me in 2020.

No-one in the family is sure what day it is, and the gloomy weather isn’t doing anything for our timekeeping. By the time we reach Plaidy, we only have half an hour left before it will begin to get dark. Fortunately, that’s plenty of time to find some winter colour.

This beach is ideal for strawberry anemones, a species that seems to like some wave energy. While I try to take photos of a stunning open anemone, its bright tentacles tucked too far under a dark overhang for my camera to capture well, the waves surge in behind me, finding a hole somewhere in my left welly.

Strawberry anemone

Undeterred by the steady seep of chilly water down my ankle, I take a close look at the tough seaweeds that have clung on at the edges of the pools through the winter storms. There are tufty pink fringes of coral weed, the frayed remains of last summer’s kelp, and, sprouting from the rocks at the pool’s entrance, there are dark clusters of wiry-looking Irish moss. Among these seaweeds are dozens of mauve stalked jellyfish dancing like fairy lights.

Stalked jellyfish – Calvadosia cruxmelitensis.

In every rocky crack and crevice alongside the pools there are crabs lurking, waiting for the returning tide. A velvet swimming crab watches me through red eyes like glowing coals.

Velvet swimming crab

Nearby, the sculpted pink spire of a painted top-shell brightens up a shady overhang that is also home to several cushion stars and bright sponges.

Painted top shell.

Everywhere I look there are colourful sea squirts, shells, fish and seaweeds. These may be the darkest days of the year, and I can feel a cold coming on, but the brightness of the shore always reminds me that spring is around the corner.

Breadcrumb sponge.

In fact, new life is beginning already in the rock pools. Before I leave I come across this 2mm long baby sea hare grazing on the seaweed. By the summer, if it survives, this tiny slug will have developed a striking brown leopard-spot colouration and will have grown large enough to fill my palm. Perhaps we will meet again?

Juvenile sea hare – Aplysia punctata

Happy New Year! May 2020 bring you health, happiness, and many, many beach adventures.

Happy New Year from Bernard the hermit! (Pagurus bernhardus).

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

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

A Winter Walk to Millendreath

There are many advantages to home educating Junior, but one of our favourite things is being free to go outside whenever we like. During the winter months, good weather and daylight coincide so infrequently that we nearly always drop everything to make the most of it. Today, Junior wants to explore our local beach and dig in the sand, so we grab our wellies, spade and camera and set out with the low morning sun glimmering from behind the clouds.

Spring comes earlier in Cornwall than it does further north, and the signs are there even though the days are still cold. The herring gulls have already moved back onto the roof-tops in our neighbourhood, and some are sitting on empty nests to deter others from moving into their territories. Buds are tightly wrapped on the hedgerow plants, waiting to open and a few hardy wildflowers are already blooming.

We hear the fulmars honking to each other on the cliffside above Plaidy before we see them. When we stop at a viewspot to look across to the Eddystone lighthouse, a male fulmar glides towards us on stiff wings before circling back to land on a ledge and touch beaks with the female that is resting there.

In the rock pools, spring is even further ahead and I have been finding sea slug spawn for a few weeks already. ‘Sea mushrooms’, the holdfasts of seaweed are appearing on the rocks and beginning to sprout from their centres. Colourful colonies of star ascidian are budding and spreading across the rocks. On one a flatworm is grazing, while another young colony is being visited by a hungry 3-spot cowrie.

Star ascidian at Plaidy beach
Star ascidian at Plaidy beach

A 3-spot cowrie closes in on a small star ascidian colony.
A 3-spot cowrie closes in on a small star ascidian colony.

The tide is wonderfully low so we scramble out to the furthest rocks we can safely reach. Junior discovers anemones and sponges. A tall rocky gully is coated in every colour of sponge, sea squirt and bryozoan, and we peer closely at their strange forms.

The overhang is coated in animal life including sponges, sea squirts and barnacles.
The overhang is coated in animal life including sponges, sea squirts and barnacles.

I spot an overhang that plunges into a pool. Even though I can see it’s too deep for my wellies, I wade in, balancing from one submerged rock to another, feeling a cold trickle down my shin as the water overtops my boots. At the edge of the rock the water is still precariously high, but I have noticed some dark, frilly tentacles in the water. Several sea cucumbers are lodged in cracks in the rock here and are busy feeding with their extended fronds. Junior crawls over the rock to get a better view of this unusual sight.

Brown sea cucumbers (Aslia lefevrei) feeding in the pool.
Brown sea cucumbers (Aslia lefevrei) feeding in the pool.

Brown sea cucumber feeding tentacles
Brown sea cucumber feeding tentacles

Edging our way through the narrow rocks, we reach the very edge of the sea. We are sheltered a little from the waves by a rocky reef further out, but the waves are still surging back and forth. In a hollow I can see a young common starfish. I tease it out of its hiding place and Junior holds it on his hand while I take photos.

One of several young common starfish we find on Plaidy beach.
One of several young common starfish we find on Plaidy beach.

Despite its name, this starfish is nothing like as common on our beaches as the other species we see here, preferring the deeper offshore waters. Junior takes a good look at its colours and its tube feet before placing it back where we found it.

We cross the rocks to the next beach, where Junior begins his sand-mining excavations while I take a walk along an old sea wall in the hope of taking a photo of shanny. These fish hide in holes out of the water while the tide is out and there are usually plenty in this wall. Of course, there are none in accessible places now that I have come to look for them, so I carry on across the beach to take photos of the lugworm casts that litter the muddy sand here.

The cast and depression in the sand mark the two ends of the lugworm's burrow.
The cast and depression in the sand mark the two ends of the lugworm’s burrow.

I am about to go back to see Junior’s work, when I see movement in a shallow pool. It looks as though there’s a tiny geyser beneath the surface throwing the sand up in a constant jet. There are several animals that like to bury themselves here, including some quirky species of prawn, but this sandy pool near the low tide mark makes me think of something else. I crouch by the pool for a few minutes without moving, scanning the sand before I see what I’m looking for. A small, sand-coloured fish is sitting unmoving in the shelter of a rock. I know it will be a weever fish.

A weever fish lying in the sand at Millendreath.
A weever fish lying in the sand at Millendreath.

Trying not to scare the fish away, I cross to the other end of the pool. It sticks its ground, watching me through shining eyes set towards the top of its head. Even as I lower my camera into the pool, it stays perfectly still, so that I can see its gaping mouth and moving gills. The mouth is unlike that of most other fish: the opening is nearly as high as the fish’s eyes and is hinged at the bottom like a tall flap. Inside it, I can see some spindly, crooked teeth.

The weever fish lies still as I approach, watching me with shining green eyes.
The weever fish lies still as I approach, watching me with shining green eyes.

I have no bucket and this fish will bury itself in the sand in an instant if I disturb it, so I just watch, putting my camera as close as I dare to frame the fish’s remarkable metallic-green eyes. Although the dark fin on the fish’s back is folded down now, it is made of venomous spines that cause painful stings to bathers in the summer.

Weever fish with its spiny fin folded down.
Weever fish with its spiny fin folded down.

Junior emerges from the hole he’s dug to look at the photos and do a beach clean before we head for home in the last of the day’s pale sunshine.

Painted topshells and a sea slug laying eggs - spring arrives early in the Cornish rock pools.
Painted topshells and a sea slug laying eggs – spring arrives early in the Cornish rock pools.

Junior's top find of the day. The yellow circles on the rock are boring sponge. This sponge drills into calcareous rocks and mollusc shells making round holes.
Junior’s top find of the day. The yellow circles on the rock are boring sponge. This sponge drills into the calcareous rocks and mollusc shells making round holes.

Full Moon in the Cornish Rock Pools

Ever since we discovered gem anemones in the pools at Plaidy last week, Junior has been planning a night-time trip to see them fluorescing under ultraviolet light. Lots of anemones glow in UV due to special proteins they contain that absorb the ultraviolet light before re-transmitting it at a longer, visible wavelength.

Snakelocks anemones are well-known in rockpooling circles for glowing a vivid, eerie green in UV and we have seen those many times, but we’re intrigued to see if gem anemones are as spectacular by night as they are by day.

Gem anemone by day
Gem anemone by day

Other-Half joins our after-dark ramble. We wrap up and walk through the deserted lanes. In the light of the rising full moon, there’s no need for torches. The stars have been out for a while already and the Eddystone lighthouse is flashing away at the horizon.

It took us quite a while to spot the gem anemones by daylight. Despite their pretty colours, they are tiny and well camouflaged among the pink encrusting seaweed that lines the pools.

We cross the sand and the heap of seaweed that the tide has brought in to the far rocks and take our UV torch out. Junior scans it over the pool and within seconds we’ve found them. They seem to light up in patterns of green and orange.

Under UV the gem anemones are easy to spot
Under UV the gem anemones are easy to spot

We kneel down and look closely at the starburst of orange that radiates out from the turquoise and pink mouth at the anemone’s centre. The green fringes to the tentacles that are sometimes visible by day are unmissable now.

Gem anemone under UV light
Gem anemone under UV light

Junior is keen to look at the sponges and seaweeds to see what they do under UV and leads me on a precarious climb towards an overhang he knows. The rocks here glow insanely orange and though it’s hard to tell what is causing this effect in the dark, it feels like either a dense red seaweed or a sponge.

Junior's orange-glowing sponge or seaweed
Junior’s orange-glowing sponge or seaweed

As we scramble over the rocks, we find more fluorescing plants and animals. A brown seaweed glows green, possibly due to micro-algae that is growing on its fronds.

Brown seaweed glowing green in places - presumably coated in a microalgae
Brown seaweed glowing green in places – presumably coated in a microalgae

Grey topshells are easy to spot because the tip of their shell glows pink.

Grey topshell in UV light
Grey topshell in UV light

We are intrigued by thin bright-blue streaks among the seaweed. It takes a while for us to realise that these are man-made threads. They feel coarse and may well be fibres from a fishing net. Many seaweeds on the shore are so tangled in them that it is almost impossible to clear the plastic fibres without damaging the seaweed.

One of many plastic fibres found tangled in the seaweed
One of many plastic fibres we find tangled in the seaweed

In a shallow, rocky pool lined with sediment more anemones are glowing. These look nothing like the gem, snakelocks or daisy anemones I’ve seen so far.

Another anemone species that fluoresces - Sagartia troglodytes.
Another anemone species that fluoresces – Sagartia troglodytes.

I turn my normal torch on them to see what species they are and I can’t see them at all. By switching back between UV and normal light I manage to pinpoint them. They are at least as small as the gem anemone, but are flecked with a marble of brown, white and orange that blends perfectly into the sand and rock around them.

Under the camera I can make out dark ‘B’ shaped markings at the base of the tentacles and realise this is Sagartia troglodytes. I don’t remember seeing this anemone before, probably because it would be almost impossible to spot in daylight.

The same Sagartia troglodytes anemone under normal torchlight is much harder to see among the sediment.
The same Sagartia troglodytes anemone under normal torchlight is much harder to see among the sediment.

I touch one of the anemones gently with a finger and it retracts in a puff of sediment, disappearing without trace.

I take photos while Junior and Other Half climb onto a high rock to watch the stars. On nights like this it is hard to tell whether the sea or the sky is shining more brightly. With a last sweep of the torch over the glowing anemones we turn away and head home for hot drinks.

Gem anemone under UV
Gem anemone under UV

This daisy anemone glowed red under UV but was a dull brown under normal light.
This daisy anemone glows red under UV but is a dull brown under normal light.

Anemones weren't the only animals out in the moonlight - this green shore crab glowed blue under the UV torch.
Anemones aren’t the only animals out in the moonlight – this green shore crab glows blue under the UV torch.

Gem anemone hunt

We weren’t really rock pooling, just going for a walk to the beach, or so we said. Junior packed his hammer and chisel in case there were fossils and I packed my camera, because you never know.

On my last wander at our local beach I had hoped to find some gem anemones to photograph, but didn’t succeed. It was worth another look for these tiny creatures, which have stripy tentacles and bright colours around their mouths when they are open, but at low tide most of them are retracted into white-striped blobs.

When retracted gem anemones look rather like an urchin test with a warty surface and white stripes down their sides.
When retracted ,gem anemones look rather like an urchin test with a warty surface and white stripes down their sides.

I left the sounds of hammering and splitting rocks behind me at the edge of the shore, where Junior was happily amusing himself on a fossil hunt, and headed towards an unseasonably glassy sea, pausing to look for anemones in the small pools on the way.

At the water’s edge, I reached a large pool too deep for gem anemones, but in the middle of the pool a submerged boulder was covered in Irish moss seaweed, providing the perfect habitat for stalked jellyfish. I looked so closely among the tangles of weed, hunting for tiny jellies, that I almost missed the huge stalked jellyfish right under my nose.

Haliclystus octoradiatus stalked jelly near Looe, Cornwall
Haliclystus octoradiatus stalked jelly near Looe, Cornwall

This was an unusually large Haliclystus octoradiatus stalked jellyfish, easily distinguished from the other species we see in Cornwall by the presence of blob-shaped primary tentacles in between its arms.

Most stalked jellyfish of this species have just one primary tentacle blob between each pair of arms, but this one had far more blobs than usual. The jelly can use these primary tentacles as anchors to grip onto the seaweed if it chooses to move, using a looping, cartwheeling motion.

I've sometimes seen a stalked jelly with one extra primary tentacle blob between its arms, but this one had lots of extras.
I’ve sometimes seen a stalked jelly with one extra primary tentacle blob between its arms, but this one had lots of extras.

In another nearby pool I spotted this colourful Calvadosia cruxmelitensis stalked jellyfish, well decorated with white nematocysts, which are its stinging cells.

Calvadosia cruxmelitensis stalked jellyfish
Calvadosia cruxmelitensis stalked jellyfish

Junior joined me at this point, wanting to show me a blenny he’d found. We scrambled nearly to the top of a high rocky outcrop in which some small pools had formed. There was no sign of his little fish, and there were no gem anemones, but there was this daisy anemone.

Daisy anemones have many layered tentacles, like daisy petals and come in all sorts of colours.
Daisy anemones have many layered tentacles, like daisy petals and come in all sorts of colours.

We carried on our expedition through a gap in the rocks to the adjoining beach where clear, shallow pools lined with pink encrusting seaweed nestled under a towering overhang carved out by the sea into the shape of a breaking wave.

Strawberry anemone
Strawberry anemone

These pools were full of anemones too and we stopped to take photos of clusters of snakelocks anemones and a rather flattened-looking strawberry anemone before I noticed the first gem anemone. It was closed up, forming a diminutive pink blob that blended perfectly into the colours of the pool. Close to it was another.

As we moved among the chain of pools we found dozens, but not a single one was open. Junior stared determinedly into every cranny, excited that the pools he had found were proving so interesting.

“There are some open anemones here,” he called out, “maybe Dahlia anemones? What do gem anemones look like when they’re open?”

I knelt on the rock beside him. At the far edge of the pool, tucked under a small ledge, I could see the white stripes of the gem anemone tentacles. Much cheering and hugging ensued.

The open gem anemones Junior found near Looe
The open gem anemones Junior found near Looe

Soon I was able to show Junior my up-close photos of the anemones so he could see why I was so obsessed with finding them. Each one had a vivid, almost fluorescent green mouth tinged with bright pink spots at its corners. The anemone’s mouths were framed in deep red and grey rays that stretched to the base of the zebra striped tentacles, some of which had flashes of green at their bases.

The mouth of the gem anemone
The mouth of the gem anemone

Truly one of our most spectacular anemones, people rarely notice the gem anemone because it is only a few centimetres across even when fully grown.

Gem anemone near Looe, Cornwall
Gem anemone near Looe, Cornwall

Junior is already planning a night time return to these pools to investigate whether these anemones will glow under the light of our ultra-violet torch. Watch this space!

Gem anemone -winter colour in the Cornish rock pools
Gem anemone -winter colour in the Cornish rock pools

Dolphins and discoveries

There’s no more auspicious start to an afternoon’s rock pooling than a dolphin display while you’re munching your pasty.

Jan from Coastwise North Devon, Junior and I were treated to an incredible leaping, spinning pod of dolphins at the start of our last Looe rockpooling foray, which could only be a good sign.

We were far too busy watching the dolphins to take any good photos - but some distant fins here just to prove there really were dolphins.
I was too busy watching the dolphins to take any good photos, but here are some distant fins.

Following a busy summer season, it was magical to have the beach to ourselves. Despite a keen wind that made it difficult to see into the more exposed pools, the sheltered gullies were full of colour.

Every colour variant of the beadlet anemone was on display in one short stretch of pools. These common anemones are often red, but here they showed off their full traffic-light range of shades. Some splayed open a shower of bright tentacles, while others were retracted, showing nothing but the distinctive blue circle at the base of their columns.

A rather green beadlet anemone with blue markings around its base and on its mouth.
A rather green beadlet anemone with blue markings around its base and on its mouth.

A closed-up orange beadlet anemone
A closed-up orange beadlet anemone

Junior’s sharp young eyes were focused on the task and he brought us several isopods to identify. These minute woodlouse-type creatures swam around our pot-lids at high speed while we tried to photograph their tails. All of them had two prongs on their backs, so were male Dynamene bidentata.

One of Junior's isopods - a Dynamene bidentata
One of Junior’s isopods – a Dynamene bidentata

We used our cameras to focus in on the blob-like bodies of the Ascidia mentula sea squirts, which we found attached to several rocks. From a distance, they have a pink tinge. Close-up, they seem to be gearing up for fireworks night, with bursting patterns of red sparks along their sides.

Pink fireworks - patterning on an Ascidia mentula sea squirt.
Pink fireworks – patterning on an Ascidia mentula sea squirt.

Lurking inside the sediment-filled layers of a fractured rock, was a colony of Thalassema thalassema spoon worms. These wonderfully alien creatures have plump pink bodies like an overfed grubs, with an extendible, frilled proboscis.

One of many contenders for the 'strangest animal in the rock pools' award - the echurian worm Thalassema thalassema
One of many contenders for the ‘strangest animal in the rock pools’ award – the echiuran worm Thalassema thalassema

Unlike many other marine worms that speed around on bristly legs or swim with paddles, Thalassema thalassema seems to have no efficient means of locomotion.  Instead, it rolls contentedly in the muddy sand, feeding on detritus.

These worms alarm me with their indolence. I always suspect that, like most vulnerable-seeming marine animals, they must have some secret defence. Many worms have a impressive set of biting jaws, but despite my wariness this species is safe to handle. I think.

Among the dense carpet of animal colonies, among them sponges, sea squirts, bryozoans and hydroids, we found a smart small species of spider crab, probably Macropodia sp. It was perfectly camouflaged to hide among the seaweeds.

A perfectly decorated small spider crab (Macropodia sp.) at Hannafore
A perfectly decorated small spider crab (Macropodia sp.) at Hannafore

Further out in the lagoon, near a seagrass bed, we found several egg cases of the greater spotted catshark, Scyliorhinus stellaris. In some we could see the fresh yolk, in others the baby was forming while some were already hatched and thickly encrusted with life.

A fresh Greater spotted catshark (Scyliorhinus stellaris) egg case showing the yolk.
A fresh Greater spotted catshark (Scyliorhinus stellaris) egg case showing the yolk.

By the time we reached the rocky outcrop at the far side of the lagoon, the tide was at its lowest and we could only stay a few minutes.

Inevitably, the finds rolled in just as the tide was turning. Junior was delighted with the yellow colour of this common brittle star, Ophiothrix fragilis, which is more usually pink in colour when we see it further up the shore.

Junior's yellow brittle star
Junior’s yellow brittle star

Under one stone was a faint lattice pattern marking the spot where, earlier in the season, a clutch of clingfish eggs had been attached. Although they seemed to be long-since hatched, the site was still being watched by what was probably an anxious parent.

Cornish clingfish - Lepadogaster purpurea, Looe.
Cornish clingfish – Lepadogaster purpurea, Looe.

A speck of blue on the rock concealed a good cause for any clingfish parent to be concerned: a Calma glaucoides sea slug. Despite the elegance of its long blue cerrata, flashing their golden tips as they waved in the water, this slug could well have destroyed the entire brood of eggs, which are its food.

Calma glaucoides - a sea slug (nudibranch) that feeds on clingfish eggs.
Calma glaucoides – a sea slug (nudibranch) that feeds on clingfish eggs.

We could easily have knelt around the pool for longer, wondering at this tiny creature, but a change in the wind and a stirring of the kelp out towards the island meant that the race was on.

We sploshed and slid our way back over hidden rocks and through tangled weed that grabbed at our ankles, watching the flow of water growing by the second as the powerful tide raced in. Behind us, the water was working fast to submerge the slugs, shark eggs, anemones and brittle stars, closing the door on the watery world.

We made it back without over-topping our wellies; wishing, as always, that there was a little more time between the tides.

On the way to the shore we found this vivid green prawn with a huge left claw - at first we thought it might be a snapping prawn, but it turned out to be an unusual colour variant of the more familiar hooded shrimp.
On the way off the beachwe found this vivid green prawn with a huge left claw – an unusual colour variant of the more familiar hooded shrimp.