The weather has been generally awful so far this year and so I have not been out much. However it is March already so at least a small blog post is in order! There are loads of Worm pipefish Nerophis lumbriciformis around, some of the males carrying eggs (see also the blog header and the ‘about’ section). I found my smallest one yet. Next up a Sea urchin Psammechinus miliaris with what is probably the parasitic (or commensal?) polychaete worm Flabelligera affinis (thanks David Fenwick). After that, a slighlty out of focus shot of the hydroid Candelabrum cocksii. A few of these small individuals were sat under the first rock I turned over; I reckoned they were some type of spoon worm but they are something very different, thanks again David Fenwick, see for his much better photographs of this weird little thing here. Next the Wrinkled rock borer Hiatella arctica with siphon extended and the pretty acorn barnacle Balanus perforatus. Finally a picture of the Strawberry anemone Actinia fragacea, quite common and pretty, but I do not think I have ever posted a picture of it on the blog before. (All pics taken at Castle Beach in Falmouth btw.) I have three in my tank and it is high time for an aquarium update as well. I hope to go out tomorrow and the weekend as the tides are very low so watch this space!
The winter season is the time for beachcombing and so I was very happy that Santa gave me The Essential Guide to Beachcombing and the Strandline; a fantastic guide to objects washed on British (and NW European) shores by Steve Trewhella and Julie Hatcher. One of the things that sets it apart from other guides is that it not only covers biological ‘objects’ (shells, fish, mermaid’s purses, sea beans etc) but also strandline debris of human origin (e.g. buoys and nurdles). After a walk at Praa Sands beach, it helped me to identify the Goose barnacle Lepas pectinata. A must-have book for anyone who likes to spend time on the beach! At Praa Sands I also found several Chama bivalves attached to a tangle of rope. David Fenwick has recently described three Chama species, all from (around) Florida (there are no native species), see here for much more detail. Unfortunately it is very difficult to tell what species it is from only the lower valve of the ‘Jewel Box’. It is interesting to see that even commonly encountered bits of rope and net can be from as far as the other side of the ocean. Hopefully there will be some westerly January storms to wash up more interesting species!
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!
The lowest tide of the century so far, on a Saturday, with beautiful weather and on a stunning location: what could go wrong? Very little! St. Michael’s Mount, Marazion, Mount’s Bay is one of the most beautiful spots in Cornwall and an excellent site for rock pooling with a mixture of eelgrass beds, rocks and sandy expanses. I felt like a kid in a candy shop: wanting to turn every stone, photograph every seaweed and inspect every gully before the tide would come back in. I needed to collect some more Clawed fork weed Furcellaria lumbricalis for a cool student project. That was abundant so easy to sort. Chock full of Pheasant shells Tricolia pullus. One other amazing thing was that the place was littered with Bull huss Scyliorhinus stellaris (a.k.a. Nursehound, a.k.a. Large-spotted dogfish) mermaids purses. Mount’s bay is an important breeding ground for these sharks. The yolk was easy to spot, but the embryo’s still to small to be seen. There were loads of pretty seaweeds gently waving among the eelgrass in the crystal clear water. I saw a bright green Chameleon prawn swimming about, but the picture I took was a bit underwhelming.
I had met up with David Fenwick, so could get all species identified on the spot. Very striking was a great amount of small, fuzzy pink seaweed balls: Falkenbergia, the tetrasporophyte stage of the Harpoon weed Asparagopsis armata (it looks so different from the gametophyte stage, see some old posts, that it was long considered a separate species). Also, a picture of Bushy rainbow wrack Cystoseira tamariscifolia, simply because one cannot post too many pictures of Bushy rainbow wrack….
The find of the day (the month probably) was a Little cuttlefish Sepiola atlantica. This picture is crap, but David has made some stunning photos back in his lab and they will appear sometime soon on his aphotomarine site I am sure.