Category Archives: Molluscs

A Surprise Sea Slug

Even my family look at me strangely when I suggest rock pooling in this weather. The Met Office reckons it’s going to turn out fine, but the wind is flinging water straight into our faces and the beach is deserted. We huddle down on some damp rocks and rush to eat our pasties before the rain turns the pastry soggy.

“I wonder if people realise what you go through to put pretty pictures on your blog?” Other Half says.

I nod, watching the waves crashing onto the shore and thinking that it’s worse than that. In these conditions I’m unlikely to find much, let alone manage pretty pictures.

Fortunately, I’m wrong.

Cornish Rock Pools in Looe - fuelled by rain-soaked pasties
Cornish Rock Pools in Looe – fuelled by rain-soaked pasties

After a quarter of an hour of staring into holes in the rock, taking lots of rain-blurred photos and a few passable ones of common crab and barnacles species, I’ve established that my waterproofs are anything but waterproof. If it’s possible, the rain is getting heavier.

Volcano barnacle
Volcano barnacle

Cornish Rock Pools Junior and his dad have wandered off and are probably reaching their tolerance limit. I find a stalked jellyfish and think that’s likely to be the most exciting find of the day.

A stalked jellyfish (Calvadosia cruxmelitensis) in a pool
A stalked jellyfish (Calvadosia cruxmelitensis) in a pool

I lift the edge of one last stone. There are some thick yellow sponges and the rock is crusted over with bryozoans. Broad-clawed porcelain crabs are scuttling along and there are little banded chink shells. On the far side is a spot, maybe half a centimetre across. It’s hard to make it out, but it has a blue-ish tinge and a lined appearance, like an anemone out of the water.

I think it’s a sea slug, but it’s far too delicate to pick off the rock and even if I do there’s nowhere to put it. I need to see it in water otherwise it’s just a blob of jelly. There’s no chance of that here at the base of the gully where the waves are pounding in, so I heave the boulder up the shore and lower the side with the slug into the nearest pool.

Facelina auriculata sea slug unfurls its tentacles and cerrata in the water.
Facelina auriculata sea slug unfurls its tentacles and cerata in the water.

Shelter’s hard to come by. The surface of the pool distorts with every gust of wind and the rain goes up the back of my coat and into my ears as I lean over to hold the rock in position. Straight away, I know this is definitely a sea slug. In the water, its cerata pop up all over its back and long tentacles and rhinophores unfurl around its head.

This is the sort of colourful, beautiful slug that I’m always hoping to find and only rarely do. Under the camera it has striking red lines and markings up its cerata, white stripes down its head and an iridescent blue sheen that changes as it moves.

Facelina auriculata - the red patch behind its head is the oesophagus
Facelina auriculata – the red patch behind its head is the oesophagus

This is a new slug to me and I can’t wait to look it up when I get home to check the exact species. In the meantime, I take as many photos as I can before hauling the rock back to the same spot where I found it. That done, I rush up the beach to tell my Other Half, Cornish Rock Pools Junior and everyone else I see that day about how amazing my sea slug was.

Facelina auriculata sea slug - from different angles the colours seem to change.
Facelina auriculata sea slug – from different angles the colours seem to change.

Thanks to my pile of identification books and the quick responses of the hugely knowledgeable members of the NE Atlantic Nudibranchs forum on Facebook, I soon have it confirmed as Facelina auriculata (previously known as Facelina coronata).

This slug is found around many coasts of the UK, and is meant to feed on hydroids, although I didn’t see many in the vicinity of this one. I’m very lucky to find it intertidally on such an average tide.

If you think rock pooling isn’t a normal sort of thing to do in January, I can understand that. You’re probably right and I think my family would agree with you, but you never know what’s going to turn up next in the Cornish Rock Pools.

Sometimes it’s worth braving the horizontal rain just in case.

See - it's lovely out there! Looe rock pooling in January.
See – it’s lovely out there! Looe rock pooling in January.
A Xantho pilipes crab - they vary in colour but always have hairy back legs.
A Xantho pilipes crab – they vary in colour but always have hairy back legs.
And did I mention I found a sea slug? So excited...
And did I mention I found a sea slug? So excited…

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.

 

 

 

For the love of sea slugs…

I love sea slugs a bit more than is probably usual. My other half even made sure I have the t-shirt, which I wear with pride in the Cornish rock pools despite the odd looks it gets me.

Trend setting in my waterlogged wellies and 'I love sea slugs' t-shirt.
Trend setting in my waterlogged wellies and ‘I love sea slugs’ t-shirt. Hannafore beach, Looe.

If you don’t already have your own t-shirt, it might be that you haven’t yet met these amazing little creatures. Unlike land slugs, sea slugs come in a mind-boggling variety of colours and shapes and have cool super-powers.

So, this week I’ve been braving the traditional British summer-holiday weather to find top slugs to convert you to the cause. My lucky t-shirt worked its wonders… Continue reading For the love of sea slugs…

The One That Got Away… Cuttlefish in a Cornish Rock Pool

If you’ve ever been rockpooling, you’ll know the feeling: you’re in the zone, bottom high, head down, lifting a rock or staring into the water when a movement catches your eye. While you’re registering that it’s some interesting creature you’ve never found before, said creature is darting away under an overhang or boulder never to be seen again.

My camera is full of “things that were there only a millisecond before”.

Not the most accomplished photo of a Greater pipefish as long as my arm!
Not the most accomplished photo of a Greater pipefish as long as my arm!

So, you’ll have to take my word for it that I finally encountered an animal I’ve been longing to find in a pool. After four decades of failure, my big moment came while I was taking some friends rock pooling this week. Continue reading The One That Got Away… Cuttlefish in a Cornish Rock Pool

A predator among the fish eggs: Calma gobioophaga sea slug

If you read this blog regularly, you’ve probably noticed a pattern: I bimble about the Cornish rock pools looking for an exciting creature, fail completely, then find something unexpected. Well, hopefully you like the format because this week is no exception. I go on a quest to find fish eggs and discover this rare sea slug.

Continue reading A predator among the fish eggs: Calma gobioophaga sea slug

A Shell Collecting Bonanza on Looe Beach

After a week of ear-numbing northerlies, the low January sunshine is at last winning through. Junior sets to work with his bucket and spade, attempting to create a sand fort that can be seen from space while I take a stroll at the water’s edge.

Looe Beach - a herring gull is also checking out the pile of shells at the water's edge
Looe Beach – a herring gull is also checking out the pile of shells at the water’s edge

The stretch of sand that forms Looe beach is ideal for summer holidaymakers to lounge on, but generally offers little to the rockpooler, unlike the surrounding shores. Today is different; probably due to a combination of large tides and strong winds from an unusual direction.

Glistening mounds of shells are heaped the length of the shore, and are being nudged onwards by the incoming tide. They crack under my feet despite my efforts not to trample them. 

Shells on Looe beach
Shells on Looe beach

It’s not unusual to see the odd limpet or a few mussel shells here – the harbour is carpeted with them – but this haul of shells is not just large, it’s more diverse than usual. There’s such a kaleidoscope of blues, whites, oranges and pinks that I have to get in close to focus on individual shells. Continue reading A Shell Collecting Bonanza on Looe Beach

Home from Home: Quiberon in Brittany

Things have been quiet on this page the last couple of months. Cornish Rock Pools Junior, Other Half and I took an extended holiday to visit the towns and beaches of Brittany. As always our travels had a bit of a marine theme…

Est-ce que c’est un anémone?” the eager child in the dark-rimmed spectacles asks. We explain what a ‘stalked jellyfish’ is to the class of seven-year-olds. “Jellyfish!” they chant.

 

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

Between fascinating excursions to the fire station and the sardine factory, we are giving impromptu English lessons to a class of primary school students during our twinning visit to Quiberon in Brittany.

 

We have covered the words goby, crab, jellyfish and shark so far and there’s still a sea of raised hands. The children seem desperate to tell us about their finds around the shores of Quiberon. Continue reading Home from Home: Quiberon in Brittany