Tag Archives: crab

Cushion Starfish and Babies Galore – Summer Rockpooling in Looe.

The sun is shining, the tide is going out and I’m wearing my ‘new’ blue sunglasses that I found in a rock pool last week. Junior and I are searching for signs of new life on the sheltered shore at Looe. Most of all, we are looking for cushion starfish eggs.

We aren’t the only ones out on the beach. Grey herons, egrets, oystercatchers, great black-backed gulls and crows, many with hungry nestlings to feed, are taking a keen interest in the pools and rocks. We give the birds plenty of space and settle ourselves by a mid-shore pool.

There is always lots going on here. Colonies of light-bulb sea squirts are sprouting up around the rocks, hermit crabs scuttle across the gravel and prawns swim over to see what we are doing – or perhaps to see if we are edible.

Light bulb sea squirts.

Under a rock adorned with a brilliant blue patch of Terpios fugax sponge, a rock goby is lying still, watching me through small eyes.

Terpios fugax – a blue sponge
Goby

Another goby close by, its head poking out from under a stone. There is no sign of any rock goby eggs, but as I check the underside of the rock, something glides along its surface.

Spot the fish

It’s hard to see what the tiny creature is. It looks as though it is changing colour as it moves, but this is because I am seeing straight through its body to the colours of the algae and sponges. After a few attempts, I manage to zoom in on the baby fish, which rests only for a few seconds at a time before zipping forward in a new direction.

The baby fish is very transparent.

This is probably a baby goby. As the summer goes on, many quiet mid-shore pools will hold large populations of tiny gobies and blennies.

The juvenile fish’s organs and spine can be seen clearly in its transparent body.

The cushion star Asterina gibbosa is a common rock pool starfish here in Cornwall, easily recognized by its puffy body and short, stiff, arms. These little starfish all start life as males and then become hermaphrodites (with both male and female organs) as they grow.

Unlike many other species of starfish, these cushion stars do not spawn into the plankton but lay a clutch of bright orange eggs. I sometimes find newly-laid eggs several times.

Cushion stars (Asterina gibbosa) laying eggs

When the eggs are developing, the curled-up legs of a baby starfish can just be seen.

Developing cushion star eggs.

This area of the beach seems to be a popular egg-laying site for the cushion starfish, so today I am hoping to fully developed or just-hatched eggs.

I search the pool, gently lifting a few stones before replacing them exactly as they were. This pool is crowded with St Piran’s and common hermit crabs of all sizes. The high population means that there is competition for shells. One St Piran’s hermit crab is occupying a very battered dog-whelk shell with half of the back missing – it’s better than nothing.

St Piran’s hermit crab in a broken dog whelk shell.

A Xantho hydrophilus crab wanders past me. From the way her tail sticks out a little behind her shell, I can see that she must be carrying eggs. I take a quick look, keeping her in the water and cradling her to keep her eggs safe. The tiny black spots on the eggs show that they are near hatching. Under my camera I can see all the little eyes staring out.

Xantho hydrophilus crab – female with eggs. The feathery accessories around her tail keep the eggs in place.

When her eggs are ready to hatch, the crab will release them into the sea, flapping her tail to send them on their way. The baby crabs will swim in the plankton for a while before gradually changing into their final form and settling.

Xantho hydrophilus crab eggs looking ready to hatch

Finally, I come across a small patch of orange cushion star eggs under a rock. I crouch down and put my camera in the water. These eggs look a little different to others I have found. It takes me a moment to realise why: they have hatched!

Instead of eggs, I am looking at hundreds of minuscule orange cushion stars, all very gradually extending their little tube feet and beginning to move and explore.

The cushion starfish eggs have hatched. Asterina gibbosa juveniles.

Most of the cushion starfish babies are still piled up together in a huddle, but some are a few centimetres away from the crowd, already taking their first journey alone in the rock pool.

I am entranced. So much so, that I don’t notice that I am sitting in the water getting a wet bottom while I take photos. I could stay watching this forever, but I want to share it with Junior.

A bundle of newly-hatched baby cushion stars.

Junior goes through the same process as me, seeing the eggs and taking a few shots on his camera before realising what he is looking at. He’s seen most things in the rock pools by now so it takes something special to impress him. This is something very special.

Newly-hatched cushion starfish.

Cushion stars are lovely; baby cushion stars are pure magic. Once again, the rock pools have exceeded all our expectations. We will never know how things turn out for these particular baby starfish, but we may well meet some of them again as adults on our future visits to our local shore.

If you are visiting the beach this summer, be sure to rock pool responsibly and safely. Check the tides and leave everything as you found it. Read my top tips for successful rock pooling.

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Winter Solstice Rock Pooling

It’s the shortest day of the year, but there’s no shortage of colour and life in the rock pools here in Looe.

I try out a pool I’ve not explored before and am blown away by the variety of animals going about their day, searching for food and shelter.

Easily my favourite find of the day is this European three-spot cowrie. Although they’re not uncommon here on the south-east coast of Cornwall, at low tide they’re usually retracted in their shells  or abseiling from the rocks on a mucous thread.

To find one fully extended out of its shell, its orange syphon probing the weeds and its leopard-print mantle curled around its shell, is fabulous. I’ve always loved finding these shells washed up on the beach, but the live animal is incredibly colourful. It looks far too tropical for our cold waters.

European three-spot cowrie looking glamorous
European three-spot cowrie looking glamorous

European three-spot cowrie
European three-spot cowrie

It’s not a great low tide but this large, shallow pool is ideal for all sorts of creatures.

Painted top shells are plentiful in this pool - there must be lots of food for them.
Painted top shells are plentiful in this pool – there must be lots of food for them.

Like the cowrie, this thick-lipped dog whelk has a long syphon.
Like the cowrie, this thick-lipped dog whelk has a long syphon.

A Velvet swimming crab lurking under an overhang
A Velvet swimming crab lurking under an overhang

These hydroids and bryozoans have their feeding tentacles out
These hydroids and bryozoans have their feeding tentacles out

A stalked jellyfish - Calvadosia cruxmelitensis
A stalked jellyfish – Calvadosia cruxmelitensis

Worm pipefish
Worm pipefish

A young snakelocks anemone
A young snakelocks anemone

Everywhere I look, there are more animals going about their business. Hermit crabs scurry past me and a fish takes shelter under my welly.

From now on, the days will get longer, and before long the sea slugs and fish will begin to move in to the shore to spawn. It seems some can’t wait for spring – even today I find a pair of Berthella plumula sea slugs under a stone!

If you’re in Cornwall this Christmas, take a look at the rock pools. You won’t be disappointed.

Nadelik Lowen!

Berthella plumula sea slug - I find two under a rock so it looks like they're planning to spawn soon.
Berthella plumula sea slug – I find two under a rock so it looks like they’re planning to spawn soon.

Who needs a Christmas tree when you can just decorate yourself in seaweed? 'Decorator' spider crab - Macropodia sp.
Who needs a Christmas tree when you can just decorate yourself in seaweed? ‘Decorator’ spider crab – Macropodia sp.

 

 

 

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

‘The best day of my life.’ – Rockpooling with Cornwall Home Educators

It’s amazing to watch the rock pools appear. Just an hour ago, as we ate our picnic on Hannafore beach, two ladies were swimming just a hundred metres away. Now the tide has slipped back to reveal the dark, alluring rocks. An egret flies down to stalk the distant pools and oystercatchers follow, trilling loudly.

Hannafore Beach with Looe Island Nature Reserve in the background.
Hannafore Beach with Looe Island Nature Reserve in the background.

‘I want to go rockpooling. Now. Now,’ a little boy pleads, dragging on my arm. Tide and time can never move fast enough when you’re five. Continue reading ‘The best day of my life.’ – Rockpooling with Cornwall Home Educators