I have not been tempted to go back snorkeling yet, but had an hour of nice rockpooling last Saturday, at beautiful Carne Beach on the Roseland Peninsula. I had been here only once before, and found my first stalked jellyfish then. The stalked jellies (Haliclystus octoradiatus) where still there, in different colours: brown, yellow and grey (I will keep to my resolution to record my findings from now on, when I find the time). My old trusted iPhone 4S finally gave up the ghost last week so I upgraded to an iPhone SE which proved a real upgrade. (I was too lazy to bring out the Canon G16 in the underwaterhousing, which would not have been much use anyway as the pools here are very shallow.) The pools were teeming with (mating) polychaete worms and there were many juvenile Sea hares about as well. I saw whole mats of pink wriggling tentacles sticking out of the sand, something I had never seen before. These (most likely) belong to the worm Cirriformia tentaculata, quickly identified by David Fenwick, see here for very good photos of the whole animal on his aphotomarine site in addition to the rather bad snap here. I found a hermit crab inhabiting the shell of a (juvenile) pelican’s foot Aporrhais pespelecani, a species that shares the sandy beach with the razor clams that were washed up all around. The highlight for me were the anemones. Snakelocks and strawberries were common, and in addition to red Beadlet anemones, there were green ones as well (I never see these in Falmouth). Some pools at the edge of the rocks and the beach were filled with Daisy-, Gem- and Dahlia anemones. I am ready for some more seaside adventures, but the weather is rarely cooperating these days. More on the blog soon I hope!
This Sunday we went on a lovely walk from Helford Village to St. Anthony in Meneage on the south coast of the Helford river. The tide was very low, so we decided to follow the mud flats for a bit before heading to the woodlands. The mud flats are a brown-grey and strewn with shells, pebbels and, unfortunately, litter. Not as pretty as the rock pools, but still interesting. There were small banks with mussels, cockels, slipper limpets and oysters, both the native oyster Ostrea edulis (quite some juveniles) as well as the invasive Pacific (or Portuguese) oyster Magallana gigas. Of course also the abundant, barnacle-covered periwinkles Littorina litorea. I saw my first Auger shell Turritella communis (which does not reflect rarity at all, just the fact that I usually stick to rocky shores); the small shells around it are Needle whelks Bittium reticulatum. Finally a Chinaman’s hat (probably no longer the prefered nomenclature!?) Calyptraea chinensis.We met up with David Fenwick and partner-in-crime Carol who were busy sampling around Treath. David’s interest was caught by a mooring rope covered in seasquirts, and a boxful was collected for careful examination under the microscope later. The clump I am holding below shows the Compass seasquirt Asterocarpa humilis (red, middle) (invasive), Morchellium argus (orange, top) (native), the Dirty seasquirt Ascidiella aspersa (three grey ones) (native) and the Creeping seasquirt Perophora japonica (tiny yellow zoids connected by stolons growing over the Ascidiella) (invasive). Astonishingly, by the next day, in a single tupperware box filled with muddy seasquirts, David had found 70 species! (With 142 species recorded in total on the day.) To finish this post full of grey blobs and brownish molluscs, I am adding photos David made of four out of nine species of Heterobranchs (Nudibranchs ‘proper’ as well as Ophistobranchs) present in the sample. Stunning images and proof that there is tremendous biodiversity to be found on a muddy bank if you know how to look for it. More of David’s nudibranch work is featured in this old post. See for his continously expanding collection of images, from seaweeds to fish and from tiny marine fungi to stranded seaturtles, aphotomarine.com.
It was a glorious bank holiday morning today and high time for another dive before the season is over. This was a dive just by myself; I had never done that before and I kept it very easy with a maximum depth of 5 meters so could surface with two kicks if needed (it was low tide so I needed to go less deep to begin with). I chose the eelgrass beds of the Helford river to play around with my new camera, a very different habitat than last weeks Maerl dive In the Fal estuary. Unfortunately no catsharks or thornback rays this time, but there were some nice invertebrates to practice on (I did not bother with the fish, way too difficult). Although I still have a long way to go to get anywhere near the quality of some of the photo’s I see on various facebook groups and blogs, it is definitely a lot easier to take good pictures with my new camera. Compare for instance the photo of a Necklace shell Euspira catena below with that of a pic taken with my old camera. Next, two very different molluscs: the Hard-shell clam Mercenaria mercenaria (introduced from North America, there called ‘Quahog’) and the Sea hare Aplysia punctata. The latter can be abundant but it is rare at the moment. The one I saw was not the usual brown but very pale, I have no idea how uncommon this colouration is. Hermit crabs are always common here however. Some of these belong to the species Pagurus prideaux, as the shell they inhabit is covered in the Cloak anemone Adamsia palliata (creamy with purple spots on the left of the shell, need to take some close-ups of that one next time). One crab was covered in the thin, white acontia threads of its anemone, which it might have induced from its partner for defence. The last photo is of the Football jersey worm Tubulanus annulatus, a very distinctive nemertean worm that I could easily identify through the excellent aphotomarine website. Now I need to get serious about the camera settings and practice, practice, practice…
This Saturday I was at the marina in Newlyn, where local natural history expert David Fenwick was kindly showing me how he obtains the samples he finds so many creatures in (worms, copepods, tunicates, forams and many other things). Todays focus was on nudibranchs, arguably the most beautiful group of little critters. David has recorded an amazing 46 nudibranch species from these pontoons alone! As this is the most Southwesterly pontoon in the country, it is a bit of a ‘sentinel site’ for southern species with northward-shifting ranges. Indeed David has found a species new to the UK that has also been discovered in the south of Spain and possibly off the coast of Morocco. He often sends samples away to (inter)national labs for sequencing and further investigation and frequently shares his finds on facebook (see the links page for relevant facebook groups). For all things marine in Cornwall see his website: Aphotomarine, an edicational resource dedicated mainly to the photography and diversity of marine life that is found in the coastal waters and rockpools of south-west England. Also check out his Aphotofungi, Aphotoflora, Aphotofauna and Stauromedusae.uk. Luckily for me, I can show off some of David’s images in this post too.
The drill: scrape off seaweeds (mainly kelps) covered in tunicates, hydroids, other seaweeds and silt (very mucky business, especially when collected lying on a pontoon covered in seagull-excrement). Next, vigorously wash the seaweeds in a bucket. Sieve the resulting silty water, pick out larger objects (sea squirts etc) from the sieve and gently wash the silt away in a fresh bucket. Then transfer the material to a white tray for preliminary inspection. Some nudibranchs can be observed this way, but the bulk of the animals only show themselves after the sample has been brough home. In warm weather, samples can get deoxygenated, so a battery-powered airpump is a good thing to have. To avoid sloshing, plastic vessels are filled to the brim by opening the lid slightly when held underwater.Back home, samples are placed in the fridge and subsamples are periodically checked under the stereomicroscope. Most animals are a bit more active in the cooled water but some are not. Some come out in the dark, others in the light, so changing the conditions is necessary to see everything that is hidden in the debris. David processed the samples that same afternoon and indeed a lot more came crawling out! From top to bottom: Cuthona amoena, C. foliata, Doto sp., Eubranchus farrani, Facelina annulicornis, F. auriculata, Polycera faeroensis, Elysia viridis (juvenile), Palio nothus, Aegirus punctilucens (juvenile) and Polycera quadrilineata (same species at the top of the post). For more beautiful nudibranch photos see the relevant Aphotomarine section. A very cool activity indeed, although at this point in my life I have not enough time at my disposal to do it justice…However, there definitely will be some smaller olloclip-iPhone sessions at Mylor marina soon!
It 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:On 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!
I have added a bunch of new links to the Links Page. Although I really like the WordPress ‘Booklite‘ theme, it is not great for listing things so I have added the links to descriptive text instead. One of the new links is a flickr stream of beautiful macro photographs of Gastropods and Barnacles by Wales-based Morddyn (Ian Smith). Below one example of a very small species (that I discovered in my aquarium once), Cerithiopsis tubercularis:
A lot of different creatures live among and on seaweeds. One abundant and species-rich group are the Bryozoans or Moss animals, which are not the easiest of critters to make sense of (then again, which are!?). Here are three species common on seaweeds, identified with the help of David Fenwicks excellent Aphotomarine site. A Sea chervil Alcyonidium diaphanum, Flustrellidra hispida and a close-up of Tubulipora plumosa:
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: Lots 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): Still, 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:
The Breadcrumb sponge Halicondria panicea can be very nicely coloured: There 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): One colony-forming tunicate looked superficially like Botryllus but was much bigger and less pretty, it might be Aplidium nordmanni: Quite a lot of Sting winkles Ocenebra erinacea were around as well:Finally, 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):
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):
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):