Tag Archives: fish

Who Needs Mythical Beasts? Rocket Jellies, Snakelocks Anemones and a Dragonet

When my son was younger he thought he saw a kraken. I returned from releasing a crab after an event for the local Cub pack to find him and a friend staring out over the sea, shading their eyes to better spot tentacle tips or unusual splashes among the waves. They were quite sure it was out there.

I watched with them for a long time, until the tide was lapping at our boots, because you never know what might be in the sea. A giant squid would be unusual, but our oceans are full of things that are so weird we are only just beginning to understand them. We sometimes see seals, dolphins and fish feeding frenzies, so why not a kraken?

Since then, my son has grown up a lot and is less sure that there are krakens in Looe. We no longer spend much time hiding in the woods looking for dragons or watching the waves for sea serpents. Junior still loves mythology, Cornish and otherwise, but knows that the real world has as much strangeness as fiction.

We are two minutes into this week’s rock pool expedition when he calls to me urgently to look at a thing he’s found.

Junior at work!

“I think it’s a hydroid medusa,” he says, because there’s not much he doesn’t recognize these days. “Quick, it’s going to get away.”

I grab a pot and wade over to where he is pointing. Staring into the tangle of colourful seaweeds, at first I see nothing.

A flicker of movement has me scooping up the water and when I look in my pot there is a tiny creature zipping from side to side, throwing itself against the edges of the pot like a trapped Trogglehumper. Of course, this creature is not a Roald Dahl creation, but an actual, fabulous marine animal. My books call it a ‘root arm jelly’, although Junior and I know it by a different name.

Whoosh! A rocket jelly. (Cladonema radiatum – aka the root arm jelly).

“Rocket jelly!” we shriek in delight.

With great care, we transfer the jelly into the lid of the pot to see it better.

The underside of the hydroid medusa (Cladonema radiatum – the root arm jelly)

The main part of its body, measuring less than a centimetre, is a perfectly transparent dome, through which we can see its rocket shaped internal parts. Pointing downwards, a mouth fringed with ball-shaped structures is feeling about, moving left and right.

The jelly’s transparent body with dark eyespots around the edge. Root arm jelly (Cladonema radiatum).

At the base of the medusa’s dome there are several dark eyespots. Spreading out at around them, like the fire below a rocket, are the most incredible red tentacles. They are branched, curled and almost feathery. As we watch they expand and contract, feel and reach.

Every time I focus on the medusa, it fires itself off in a new direction. Zooming from one side of the petri dish to another in an instant.

I have never seen a medusa with such expanded tentacles before, but I am sure this is the same species of ‘rocket jelly’ we have seen before (Cladonema radiatum).

Those little tentacles pack a strong sting for their size; it is an efficient little predator. I always find it hard to comprehend is that this free-swimming, speedy jelly is the reproductive stage of a colonial hydroid: an organism which lives attached to rocks or seaweed and doesn’t move from the spot.

Obelia geniculata - a hydroid known as 'sea fir'.
Hydroids like this sea fir, Obelia geniculata, live attached to seaweeds.

While Junior takes photos of the rocket jelly, I notice a young fish glide over the sand, stopping near my feet. It has mottled markings in blue, orange and brown, which look colourful and yet provide the fish with an ideal camouflage among the sand, pebbles and shell fragments. Its eyes are mounted high on its head, giving it a wide field of vision. This is the wonderfully-named dragonet.

Dragonet lying still on the sand. Despite the lovely colours, it is perfectly camouflaged.

These captivating fish have a distinctive way of swimming in short bursts across the seafloor and they have an exceptionally long first dorsal fin. Male dragonets raise this sail-like fin as part of a mating dance, which I would love to see some day! It is perhaps this display, somehow reminiscent of a frill-neck lizard opening its collar, that gives these fish their fabulous name.

Dragonet saying hello to my camera!

The dragonet comes unusually close to my camera before scudding away over the sand, becoming invisible every time it stops.

I take some photos of another striking animal with a mythical name, which seems to abound in this pool: the snakelocks anemone. Just like the Medusa of Roman mythology, this anemone has long, green moving ‘hair’. Instead of being made of snakes, though, the anemone’s locks are its stinging tentacles. They are pretty but deadly, especially if you are a small animal, or even quite a big one. We’ve often seen crab legs hanging out the mouths of these large anemones.

Snakelocks anemones in the rock pool.

Some snakelocks anemones are neon green with purple tips, while others are a muted beige colour. Out of the water, they are a sorry squidgy mess of jelly but in the pools their tentacles move and flow, sometimes with the current, sometimes reaching and grabbing for prey they have sensed.

Snakelocks anemone – some are green and some are beige.

The chug of a boat makes us look up. Unusually for this area, there is a dive boat close to the rocks. Two-by-two, people in Scuba gear pop up on the surface and clamber aboard. I wonder what they have seen and whether they have noticed the tiny rocket jellies, lurking dragonets or even the medusa-haired snakelocks anemones.

Dive boat close in to shore.

Perhaps the divers have seen the kraken as they’ve explored the sea just beyond our reach. Even if they have, we don’t feel we have missed out by being confined to the land. The rock pools are full of truly magical beasts. You just have to look.

Snakelocks tentacles waving in the current.

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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Sharing the Love of Rockpooling

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

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

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

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

Hatchlings in the rock pools at Port Nadler

A sunny bank holiday weekend followed by a sunny half-term week is nothing short of a miracle. That the second weekend also coincided with some big spring tides is more amazing still.

I’ve seen some wonderful photos this week of rockpooling finds all around Cornwall. Some fabulous creatures. And if you haven’t been able to explore the shore yourself, Springwatch tonight (8th June) are going to be showing footage of the remarkable comeback of the Clybanarius ethryropus (nope, still can’t pronounce it) hermit crab, filmed with Cornwall Wildlife Trust at Castle Beach, Falmouth.

The stars of my pretty perfect day of wading through pools in the blazing sunshine at Port Nadler, near Looe, were the baby fish.

There are plenty of young fish around at the moment but the new hatchlings can hard to spot. I took this photo of clingfish eggs to capture the eyes staring out of each eggs and the little spotty tails curled round them.

Clingfish eggs hatching in a Cornish rock pool.
Clingfish eggs hatching in a Cornish rock pool.

It was only when I uploaded photo to my laptop that I realised I’d managed to capture my first hatchling (in the centre of the picture). I can’t get enough of those golden eyes.

A recently hatched Cornish clingfish among its egg-bound siblings
A recently hatched Cornish clingfish among its egg-bound siblings

Fish often stick around to guard their eggs and sure enough there was a proud parent next to this rock.

An adult Cornish clingfish showing the typical beaky nose, antenna by the eyes and blue patches on the head.
An adult Cornish clingfish showing the typical beaky nose, antenna by the eyes and blue patches on the head.

I was up to my waist between rocks leading to the open sea when I saw this pale creature, about 4cm long, wriggling amongst the darker kelp. From its elongated, looping form I expected a worm.

A recently-hatched Greater pipefish baby.
A recently-hatched Greater pipefish baby.

On closer inspection the large eyes and fins were clear. This is the first time I’ve ever seen a baby pipefish.

A baby Greater pipefish with yolk sac still attached. The large eyes and long snout are reminiscent of its cousins, the seahorses.
A baby Greater pipefish with yolk sac still attached. The large eyes and long snout are reminiscent of its cousins, the seahorses.

Judging by the yolk sac still attached to its belly, this little fish hatched very recently. I saw several more in the water, their curling movements reminding me of their cousins the seahorses. I wondered if the dad was close by – like seahorses, the male pipefish looks after the gestating eggs in his pouch until they hatch – but he’d be too well camouflaged to spot in this seaweed.

 The rocks were crawling with crabs and the pools were busy with the fry of larger fish that use these sheltered waters as nurseries. My camera battery was low, but this Limacia clavigera sea slug was worth draining my battery for.

A Limacia clavigera sea slug on the move.
A Limacia clavigera sea slug on the move.

 The water was so warm after a week of sun that I put on my snorkel for the first time this year and enjoyed a leisurely float across the bay, watching wrasse skirting the rocks and snakelocks anemones waving in the current. 

If this weather carries on, I can see myself returning to Port Nadler regularly this summer to watch the baby fish growing up.

Cornish Rock Pools junior drying off in the sunshine at Port Nadler, near Looe.
Cornish Rock Pools junior drying off in the sunshine at Port Nadler, near Looe.

Autumn in the Cornish Rock Pools

Autumn is a time of great change in the Cornish rock pools, but on the surface this could be mid-summer. The water is warm, the sun is blazing and an immense low tide is beckoning. I accompany a group of under-fives and their parents as they set out to investigate.

On land, the yellow tinge of autumn is only just creeping across the woods, but in the rock pools, the seaweeds have already died back. The invasive Japanese wireweed (Sargassum muticum) that clogs the pools all summer with long tresses like knotted hair all summer has thinned away, making it easier to see into the water.

A daisy anemone in clear water
A daisy anemone in clear water

There are many species that visit the shore in spring and summer to breed and some of these are long gone, but there’s still plenty to see. I was surprised to find a worm pipefish (Nerophys lumbriciformis) with eggs this late in the year. The pipefish are closely related to the seahorses, so it is the male that carries the eggs in a special groove on his belly. Continue reading Autumn in the Cornish Rock Pools

A perfect rockpool ramble in Looe

Friday was the ideal day for a Cornish rockpool ramble with warm weather and calm conditions. Over a hundred people joined the Looe Marine Conservation Group rockpool event and I’m sure other rockpooling sessions around the Cornwall were similarly well attended. (Here’s a list of what’s on this summer).

Learning about crabs with a Looe Marine Conservation Group volunteer
Learning about crabs with a Looe Marine Conservation Group volunteer

Continue reading A perfect rockpool ramble in Looe

Rockpooling With Mum

My mum will be seventy this year, but she cuts a sprightly figure as she steps across the rocks at Castle Beach. In a rare, precious moment we have time together, surrounded by glittering pools and a wide open bay.

Mum exploring Cornish rock pools.
Rockpooling with Mum, Castle Beach, Cornwall.

These are the moments we hoped for not so many years ago when Mum was lying in a hospital bed, hooked up to a blood transfusion to give her the strength to make it through her cancer operation. Continue reading Rockpooling With Mum

Boiling Seas and Shipwrecked Sailors

There’s no mistaking a change in our rock pools this week. There’s a new chill in the Cornish sea breeze. The shrill cries of swallows swooping over the water and children jumping the waves will soon fall silent as the days shorten and the autumn gales brew. The seas, however, are bursting with life.

Stranded fish
A fish stranded in a Cornish rock pool

Continue reading Boiling Seas and Shipwrecked Sailors