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!
Tag Archives: Stalked jellyfish
a very low tide at Castle beach
There were exceptionally low tides this weekend so I was quite stoked to get out and find some new species in what is normally the subtidal. It was raining and even hailing quite a bit but we were on a mission! Fortunately, the sun came out later and my jeans could dry up. Sea urchins are not common in the rock pools that are usually accessible at low tide, but they are quite common a little deeper. The same goes for Sea cucumbers. These are hardly ever pretty but the following species is ugly even in holothurian terms. According to David Fenwick it is a Pawsonia saxicola (I have seen a prettier incarnation before):
I noticed a little gastropod which looked vaguely familiar on a Pawsonia when checking my pictures. I could identify it as a Eulimida species in my old Poppe and Goto ‘European Seashells’ book, which also mentioned that many species in this family parasitize echinoderms so that fitted. David Fenwick’s excellent site Aphotomarine has great pictures of pretty much all species occurring here in the Southwest, including a much better one of this Vitreolina philippi Melanella sp (identified through David’s correspondence with Jakov Prkic). David has also just launched a website dedicated to Stalked jellyfish: stauromedusa which looks amazing.
At the end of the ‘session’ I glanced something red, white and blue; a colour combination that I had seen only on photographs before. It was a single, juvenile Spiny squat lobster Galathea strigosa:
A lot of usual suspects were found as well of course, here a Cornish sucker Lepadogaster lepadogaster and a Shore rockling Gaidropsarus mediterraneus:
The rockling has a groove in front of its dorsal fin filled with hairlike fin rays that are continuously beating. Finally, not a very good picture but I’ve posted it because this is the longest animal in Britain: the Bootlace worm Lineus longissimus can grow up to 10 meters!


