Category Archives: rock pooling

Stalked Jellyfish

Posted on by under cnidarians, rock pooling, seaweeds

IMG_5675A trip to Carne Beach on the Roseland Peninsula, east of Porthscato and west of Nare Head. The beach is facing south and the sun was so bright that my iPhone pictures were all overexposed, but I’m not complaining in February! I did not have time to go rock pooling much longer than ten minutes, but in this time, I managed to find Stalked Jellyfish, as described in the previous post. Some very nice rock pools to the east of the beach (the pools to the west where the beach is called Pendower looked even better). On pretty much every Slender wart weed Gracilaria gracilis plant I found a Spotted kaleidoscope jellyfish Haliclystis octoradiatus (see stauromedusae.co.uk for all things stalked jellyfish). I also found a smaller, red species which David Fenwick ID’d as a Lucernariopsis campanulata (last two pictures). I will now keep my eyes out for these beautiful little creatures as their biology and distribution are not well-known and record my findings.

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Rock Pooling in Penzance

Posted on by under cnidarians, iPhone, rock pooling, seaweeds

IMG_5527It was a very nice day this Saturday, and the plan was to collect more seaweed species for a student project that I am supervising (see for an introduction my work blog here and for  project updates student Abi’s blog). We were very lucky to have David Fenwick Snr and his partner Carol of aphotomarine fame to help us to find and identify species (you might also know him through a variety of UK marine facebook groups). We took to the rocks beneath the Jubilee Pool in Penzance (the end of the Cornish main train line and both the most Southern en the most Western station in England). As the focus was to get new species for Abi’s project, I did not focus on photography or finding other species so I have only a few pictures to show. One exception of course was that we had to see some stalked jellyfish; this is one of the specialties of David and he has dedicated an entire website to these beautiful creatures: stauromedusaeUK. These little animals are related to jellyfish but are attached on rocks and seaweeds on the shore. Ten species have been recorded in the UK. One of the more common ones is the Spotted kaleidoscope jellyfish Haliclystus octoradiatus; although a crappy iPhone photo, the stalk, arms with secondary tentacles at the end, white nematocyst spots and gonadal sacs are clearly visible:IMG_5539On to the seaweeds: about 15 new samples were collected. A species we did not take was Creephorn Chondracanthus acicularis, which according to Davis memory was last recorded in Penzance in the 1880s (first pic). We did collect a good amount of the epiphyte Champia parvula (second pic). Unfortunately no time to pick up some Wakame from nearby Newlyn marina or go to a spot with some good Prasiola growth but all in all a very successful and enjoyable trip!IMG_5553

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Two epiphytic seaweeds

Posted on by under rock pooling, seaweeds

I have not posted too many pictures of seaweeds in rock pools because they are a real pain to properly photograph. However, when rock pooling two weeks ago in Falmouth, my friend Thor took some great pictures using his DSLR, two of which shown here. The IDs of these two epiphytic seaweeds on wracks were verified with invaluable help from Seaweeds of the NW Atlantic facebook group members: the first picture is Pylaiella littoralis (a species I had only seen on kelp sublittorally). The second species is Polysiphonia (or Vertebrata) lanosa: IMG_0074

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More Scummy Pools

Posted on by under bryozoans, crustaceans, fish, rock pooling, seaweeds, tunicates

As in Falmouth, the rock pools in Flushing are not looking that great at the moment. Lots of the Corallina has turned white/died (although the clumps in my tank are still their normal purple!). Of course, many species were still thriving, Grape pip weed Mastocarpus stellatus (top), Bunny ears Lomentaria articulata (bottom), new Thong weed Himanthalia elongata ‘buttons’ and a young blade of kelp along with some green Ulva:IMG_0977Among the seaweeds that were thriving was Slimy whip weed Chordaria flagelliformis (I am by no means a seaweed expert and I might be wrong about this, please comment if I am!) and also the beautiful Harpoon weed Asparagospis armata growing as an epiphyte on some darker coloured False eyelash weed. Harpoon weed is invasive and so a good candidate to do well int he aquarium (as most invasive species are quite opportunistic and not too finnicky). It died off in the tank before, but I decided to bring some home to try again now I have a chiller.IMG_0964

IMG_0970Another tangling invasive species: Bonnemaison’s hook weed Bonnemaisonia hamifera (a characteristic curved hook can be seen in the top-middle):IMG_1020Loads more seaweeds to be found but I will save those for another time. All kinds of tunicates pop up in spring, some of them pretty (see for instance here), some of them less so. For instance the invasive species, the Leathery sea squirt Styela clava and an out-of-focus photo of a second, large (>10 cm) species that did not get a lot of response on the NE Atlantic Tunicata FaceBook group. Aplidium nordmanni was offered, see here for a much smaller version of that species. Not a looker either in any case!IMG_1055

IMG_1030I brought my little aquarium net and found many juvenile (<1 cm) fish as well as Mysis shrimp. The fish look like gobies but it is hard to see. They were completely translucent and so you can see what this one just ate. I should take some bits of seaweed home to see what comes crawling and swimming out under a little USB microscope (quite easy to make little videos). It is hard to come up with decent images squatting and squinting on a slippery rock with a salt-encrusted mobile phone!

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scummy pools

Posted on by under eggs, molluscs, rock pooling, seaweeds, sponges, tunicates

For the first time in a while I had time to nip over to Castle Beach to do a little rock pooling. The tide wasn’t the best and the pools did not look to great either actually; this seemed to be due to a mix of some seaweed species dying off, and some not so great-looking species ones blooming: IMG_0317Lots of Wireweed, Ulva and very fine weeds (the latter are often very pretty under magnified and in water, but not so much as a blob on the rocks). What might be Desmarestia viridis (but don’t take my word for it): IMG_0319Still, there was plenty to see: Orange-clubbed sea slugs for instance and one very weird-looking creature I had never noticed before was clinging on in little groups on red seaweeds under overhangs, the annual sponge Sycon ciliatum:

IMG_0218The Breadcrumb sponge Halicondria panicea can be very nicely coloured: IMG_0240There were a lot of tunicates about. Colony-forming Morchellium argum for instance and this beauty, probably Ascidia mentula (determined by helpful folks at the ‘NE Atlantic Tunicata‘ facebook group): IMG_0276IMG_0279One colony-forming tunicate looked superficially like Botryllus but was much bigger and less pretty, it might be Aplidium nordmanni:IMG_0248 Quite a lot of Sting winkles Ocenebra erinacea were around as well:IMG_0288Finally, I spotted the orange/yellow egg masses of the Cornish sucker (or Shore clingfish) Lepadogaster lepadogaster (see here for an older post on them). However, I also found some that were greyish and had a speckled band, as well as a red dot between the eyes. Local expert David Fenwick told me these are from the Small-headed clingfish Apletodon dentatus, a species I have not yet seen the adults of (see his site for pictures): IMG_0314

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a most peculiar animal

Posted on by under rock pooling, worms

The rock around Falmouth is very soft in places, and when turning over large stones, sometimes they break and reveal interesting things (I have posted previously about the high density of worms in rocks). I recently had another rock crumbling on Castle Beach and I noticed something unusual-looking slipping away in its burrow. A Sipuncula (‘peanut worms’) or Echiura (‘spoon worms’) I thought, something not featured in any old guide anyway, so I browsed David Fenwick’s aphotomarine site where I quickly found the suspect: the Spoon worm Thalassema neptuni. The Echiura are recognised as a separate Phylum in most books, but recent research has revealed that they are not as special as they look: they are actually ‘ordinary’ Annelid worms (see this Open Access paper):

IMG_8621 The diversity of life within rocks is actually quite surprising. I have not taken a good look at all the types of worms yet, but this one stands out: a tiny Green leaf worm Eulalia viridis (looks like a sock puppet):

IMG_8643The boring bivalve Wrinkled rock borer Hiatella arctica (a juvenile):

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IMG_8636 Perhaps I should make a list of all the species living in the rock. Finally, on the rock surface, I sighted a small Sea hare Aplysia punctata for the first time in Cornwall:

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Two Sea Slugs

Posted on by under molluscs, rock pooling

Miserable weather in Flushing this Sunday, but the local critters are not going to identify themselves so out to the shore it was! Amongst a bunch of interesting finds (the tide was quite low), a Chinaman’s hat, baby Thick-lipped dog whelks and Horseman anemones. Also two slugs I had not seen before. The beautiful Grey Sea slug Aeolidia papillosa which preys on anemones (not the best picture but it was raining and my hands were cold):

IMG_8493Pictures of the Yellow-plumed Sea slug Berthella plumula in my Collins guide show quite a beautiful animal, but it was a bit underwhelming in reality. This species has an internal shell and eats colonial tunicates. I found a bunch of them huddled together (the one on the left i turned over):IMG_8475

miniature species

Posted on by under echinoderms, molluscs, rock pooling, tunicates

I usually head down straight to the lowest reaches of the shore when rock pooling, but when there is a neap tide and a lot of inshore wind as there was this weekend, you have to make do with turning rocks higher up the shore. Although biodiversity is lower, there are some species that are only found there (see for instance this recent post) and so it is actually nice to have a look there for a change. The very first rock turned over actually had a couple of interesting inhabitants underneath it. Another lifer, the tiny gastropod mollusc Onoba semicostata (surrounded by a couple of even tinier Rissoa parva), very quickly identified by members from the British Marine Mollusca facebook group:

IMG_8352The same rock had a number of the tiny (< 1 cm) Cushion star species Asterina phylactica on it as well. It is prettier than the common Cushion star Asterina gibbosa (one of my favourite aquarium species), but perhaps a bit too small to be an option for the tank.

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One other beautiful species, the colonial tunicate Botryllus schlosseri, this is a nice blue/purple one:

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