STAUROMEDUSAE UK
An online guide to the Stalked jellyfish (Stauromedusae) found
around the coastal waters of the United Kingdom and Ireland.
Includes notes on their identification, and where and how to find them.
A historic account of Lucernarians (stauromedusae) of Port Erin, Isle of Man, has already been provided on the Historical Accounts page of this website.
See - NOTE on LUCERNARIANS, Port Erin, Isle of Man. W. I. Beaumont. 1893.
The notes from the link above and to what I often refer to within this article are extracted from the -
PROCEEDINGS and TRANSACTIONS of the LIVERPOOL BIOLOGICAL SOCIETY VOL. VII., SESSION 1892-93. 1893.
page 74-75.
NOTE on LUCERNARIANS occurring in the neighbourhood of PORT ERIN, ISLE OF MAN. By W. I. Beaumont, EMMANUEL COLLEGE, CAMBRIDGE. PROCEEDINGS and TRANSACTIONS of the LIVERPOOL BIOLOGICAL SOCIETY VOL. VII., SESSION 1892-93. 1893.
page 253. [Read May 12th, 1893.]
Click on highlighted text below to view larger images.
These notes are important in that they give a historic insight into the recording and distribution of Depastrum cyathiforme, a species last found in UK waters in 1951 on the island of Lundy, off North Devon. Ref: 25th Annual Report for Lundy (1974).
Of all the historical sites for Depastrum cyathiforme in the UK, the Isle of Man was chosen because there are three reported sites for the species in the south of the island. The reported sites at Port Erin and Poolvash have very good shore access and there is car parking right next to the shore. A visit was planned from the 14th-17th July 2014 based on W.I. Beaumont's report that Depastrum cyathiforme had been found during the summer of 1892 and spring of 1983 on the south side of the bay at Port Erin, between the jetty and the breakwater. The last report of Depastrum cyathiforme for the Isle of Man was in 1900 from an unreported site.
It was of course important prior to any visit to check on more recent records for Depastrum cyathiforme from the Isle of Man, and numerous active and retired professional marine biologists that had an involvement with the Isle of Man fauna were contacted to seek further information and reports. No-one contacted had heard of the species being reported since 1900.
It was a long shot, a very long shot as I found out, as I can report with some regret that Depastrum cyathiforme was not found during my visit in July 2014. Any report would appear to be rather futile, but searching and reporting on the habitats searched could prioritize future efforts to find the species once more. If we are to find Depastrum cyathiforme in the UK then we must first visit and search sites where it has historically been found. Most Depastrum cyathiforme records are for the species from 1846 to 1909, and there may be quite significant changes to habitat and changes in environmental conditions in the 100 years since the species was largely first reported, and either through erosion, local development, water flow, turbidity or sea temperature rise. There could be quite a long list due to the lack of information we have as Depastrum cyathiforme like a few other other stauromedusae has not been studied well at all. In the case of Depastrum cyathiforme, we just don't know where it does exist, thus we do not know if it is extinct, vulnerable, or indeed locally common, at suitable sites at the right time of year.
Given Depastrum cyathiforme is known to attach to rock intertidally; I can only suggested that the species is treated as a "high priority species". Given it is a shore species, of quite specific habitat requirement, and hasn't been recorded for so long, it is quite worrying that the species hasn't been reported since Lundy in 1951. It's last occurrence in Europe was from Roscoff, France in 1976. Four stauromedusae have BAP status in England and elsewhere in the UK, the status granted in 2007 because of a decline in records. If one looks at records there has been a total decline in Depastrum cyathiforme records, with one record since 1909, yet no importance is attached to Depastrum cyathiforme at all, and it could be the most vulnerable stauromedusae we have in our waters. I call for Natural England, and other national UK bodies to fund further research as Depastrum cyathiforme needs to be found urgently to further research and assess its UK status. Sadly, assessing UK status isn't easy as funding has to come from several national bodies and all bodies would have to agree to funding any future study, the only single body that could help promote research into the status and health of this species is the European Union.
Method of searching
It had previously been reported by W.I Beaumont, that on the Isle of Man, Depastrum cyathiforme was abundant, but locally found, and occurred under rocks on the shore, in middleshore pools, and fewer but larger specimens in the Laminaria zone.
Because of the small reported size of the species, it was obvious the searching was to be a "on hands and knees search", with a good deal or crawling involved, especially when looking in rock crevices. It was of course also important to include other detailed habitat information prior to searching, and much had been written by P. H. Gosse on the subject in the mid-19th Century.
Prior to going to the Isle of Man I decided to look for Depastrum cyathiforme in Cornwall, in previously recorded and unrecorded sites, using techniques that would cover the full range of habitat reported for the species. Habitats included, underboulder communities, under rocks in pools and on the shore, in crevices and overhangs, and under layers of rocks and pebbles in pools and elsewhere. Most of the searching was obviously on hands and knees as the prey could be small, especially if immature examples of the species present.
Protective clothing would therefore be needed and tested before venturing to the Isle of Man. Normally of the shore I wear thick rubber waders with steel toe caps, but traveling light meant that I had to try something a little different; and I ended up traveling with 5mm dive boots, RDX neoprene wrap around shin and calf protectors (Ebay), thin knee supports (Poundland) and over knee RDX neoprene gell pack knee protectors (Ebay). The shin and knee protectors are recommended for gym use rather than dive use but they've been well tested now and work brilliantly, although a tad expensive. The advantage of the kit over waders is that the kit is less restrictive, lighter, and you can go anywhere deeper than you could with the waders if wearing trunks. The only disadvantage over waders is time spent putting on and taking off gear and cleaning with freshwater and drying after, waders are on and off. In all though I'm so impressed with the gear it'll now be used more often, especially as I usually spend more time on the shore on my hands and knees than standing up, dive boots and shin and knee protection gives one more versatility and thus more ability to adapt with changes in habitat.
Evening 14th July 2014
On the first evening of my stay on the 14th July I had arranged to meet with Lara Howe of the Isle of Man Wildlife Trust at 6pm. I arrived on the Isle of Man from Penzance, on a Flybe flight from Newquay, via Birmingham, and arrived for my meeting with Lara, with 10 minutes to spare. The plan was to look at the habitat on the southern shore of Port Erin, the intended search area, and from where the late 19th century records were reported, and look for safe access before venturing onto the shore. The area is reputed to be under-recorded because of access issues, issues largely due to slippery algae, but there is also a risk of being cut off by the incoming tide near the lifeboat station.
Access to the shore between the jetty and the breakwater was found not to be easy. The habitat on the middle and lowershore a mix of thick algae, Egg and Saw wrack, with large boulders, and loose and fixed rocks and stones. Egg wrack, Saw wrack, rock and rain was very challenging indeed. Many rocks were flat and a good size for looking under, not too taxing at all; sadly there were <0.1% that were sat in water, so nothing that suggested the site was indeed suitable, especially on the middleshore. My search then turned to the rocks under the lifeboat slip which was quite dark underneath, it looked a little more promising but species was not present there. By this time we had searched and sampled rocks between the jetty and just beyond the lifeboat station, rain had set in so we slowly went back to the jetty and went our separate ways. I must thank Lara here for helping me. One thing to note in this paragraph is that on looking at Fucus (a brown algae / seaweed), near the jetty as we started, I recognized an abundance of Fucus guiryi, Guiry's wrack, the species has since been confirmed by Professor Mike Guiry. I see quite a bit of this species around Penzance, Cornwall; and it appears to be overlooked on the Isle of Man because it has only fairly recently been described. Fucus guiryi has a distinct rim around the conceptacles. The species was observed on the rocks beside the jetty at Port Erin at 54.084528° N 4.765733° W.
Morning 15th July 2014 - Port Erin
My plan for the low tide of the morning of the 15th July was to search the water filled gulley within the inner breakwater at Port Erin for Depastrum and for algae dependent stauromedusae; crevices seen from the promenade, and also to sample a small part of the shore in close proximity to the breakwater. I must explain here that the Isle of Man like everywhere else has two tides per day, but the lowest tides occur on the Isle of Man between the hours of 6 and 8, so each day around mid-summer there are two tides per day that can be used to search in daylight hours. The lowest of the tides would also appear to occur in the morning! So not good if you're not an early riser, as advisable to be one the shore and in place two hours before low tide or even earlier if intending to search the middleshore as the tide recedes.
I was staying at the Falcon's Nest hotel at Port Erin; not far from the promenade on the south side of the harbour, where parking was free, and there were lots of places to park. The breakwater gulley, 54.085245° N 4.769962° W, photographed in 1894, 120 years before my visit, appeared from afar to be quite an exciting site, with lots of nooks and crannies, and algae to search under, it was only when I got there did I find I could easily enter under the inner breakwater on the south eastern side. I was extremely surprised to find colonies of Dead man's fingers, Alcyonium digitatum, and large Common sea urchin in shallow water on the large blocks that make up the structure at 54.085392° N 4.769667° W. I have never come across these on the shore in Cornwall! It's times like this I wish I could swim / dive! Other fauna included a plentiful supply of Clavelina lepadiformis, Light bulb sea squirt; Salmacina sp., the Coral worm; and the sponge Dysidea fragilis, but sadly no Acasta spongites barnacle was found in the sponge that was sampled, but worth looking for. Blocks inside the breakwater were also covered with other species of sponge. A single Devonshire cup coral was also found on one of the blocks.
Continued searching revealed other interesting distractions, and I found what I think could be the hydroid medusa Dipleurosoma typicum in the water filled gulley, but I also shared the gulley with both Moon and a small Blue jellyfish, Cyanea lamarckii, which at one point seemed to follow me, but these are quite harmless, unlike the related species the Lion's mane jellyfish. No algal attaching species of Stalked jellyfish, stauromedusae, were found on algae within the gulley, but algae were there that would support their seasonal occurrence. There were good shoals of small Pollack and Two-spotted goby, within the gulley and I was surprisingly struck on the side of my leg by rather a large Ballan wrasse at one point. On briefly looking under rocks on the lowershore, a marine beetle, Aepus robini, was found under a rock at 54.085118° N 4.769777° W. The species not a new record for Port Erin as both species of Aepus have been found there. Tens if not hundreds of harmless Moon jellyfish, some very large indeed were seen on and off the jetty at Port Erin, three possible Lion's mane jellyfish were also observed. On the high tide the beach at Port Erin was searched for jellyfish and medusae, a Lion's mane jellyfish, the UK species with the most painful sting, was collected for accurate identification and macro photography, the latter confirming the species as Cyanea capillata from the beach at 54.085475° N 4.760505° W. Blue jellyfish, which are often blue or bluish-purple, can also be yellow or orange and small individuals can look just like the more dangerous Lion's mane jellyfish.
In all a little deflating that Depastrum cyathiforme wasn't found at Port Erin but the search of the breakwater site more than made up for it as it was quite an exciting ELWS (Extra Low Water Spring) shore site. The weather and the views of Bradda Head were also quite magnificent. Winter storm damage was very obvious in places, and possibly one of the reasons why Depastrum cyathiforme wasn't found, that said, the habitat really didn't give me a buzz and I think records in the past might have been after a good spell of weather for the species, or at least in a good year or period for them, when they might occur on the shore, e.g. as part of what's called a bloom. Overall there appeared little habitat change in the past 100 years, and possibly only what might be expected, at least the gulley was still there, and images taken in 1894 and 2014 appear quite similar in terms of the nature of the shore. All hopes then went on finding the species at Poolvash, the Pool of Death, later in the day and the day after.
Evening 15th July 2014
During the afternoon of the 15th July I decided to visit Poolvash early and catch the site as close to high tide as possible to take photographs, and arrange parking next to the shore with the local farmer, the land owner. Poolvash is an Isle of Man ASSI, having status similar to the SSSI status in England. The site is as important for its local geology and fossils as it is for birds, plants and marine species. Aline Thomas and Peter Duncan of the Isle of Man Department of Fisheries have to be thanks for providing me with a license to collect 12 stauromedusae (including Depastrum cyathiforme) at Poolvash ASSI and for providing the 95% ethanol needed for specimen collection. Carrying alcohol on the aircraft proved complicated, and I of course had to leave the sharp tools in my dissection kit at home. I also missed access to a stereozoom microscope and had to rely on my camera in fading light near low tide, between eight and nine in the evening. Taking images of species 1-2mm across on rock, whilst standing in water surrounded by algae, in fading light was not easy. The supermacro camera I use is both heavy and valuable and used without a waterproof housing, fortunately it is well insured.
I systematically searched two suitable middleshore pool sites for stauromedusae and Depastrum at Poolvash as well as I was able, using all my experience and knowledge of the habit preferences of Depastrum cyathiforme. The first site at Poolvash as seen from the shore at 54.073403° N 4.680635° W, was searched as the tide receded, so I could took constant breaks to conserve energy, the breaks certainly helped my thought process, and helped me apply myself to the task in hand. I was all too aware that I was often running on adrenaline and was quite excited by the prospect of finding what I was looking for, and given it was a single species and I had been looking forward to the trip for so long, it was very important I remained calm and focused on the task in hand. Personal safety is also of paramount importance on undertaking solo searches on unfamiliar shores, so often a case of taking it easy, and using the car to get between chosen search areas. Beaumont in his 1893 paper gives no clues at all as to where he found Depastrum at Poolvash, and the area of shore is very extensive. There are two large middleshore pools where the species could occur at Poolvash, and these are separated by a spit of land opposite the farm. There are also numerous smaller middleshore pools, pools trapped in gullies that run across the shore, none of these were searched during my trip.
The large pool to the east of the spit opposite Poolvash Farm was very clear and habitat appeared to be very good habitat indeed for all shallow water and intertidal species of Stalked jellyfish, including Depastrum. The site could be considered seasonally good for the BAP species Haliclystus octoradiatus and Calvadosia campanulata, and also suitable for Craterolophus convolvulus. There were numerous suitable rocks and stones to look under, and stones under the stones, and the area looked OK and looked like it would support sustainable populations of Depastrum cyathiforme. However none were found within this search area, and I had to press on and visit the second site I had planned to visit, to an area identified by looking at aerial photography using Google Maps. This second site was my first choice of site for Depastrum cyathiforme given its geological similarities to Weymouth and Southend Harbour, Arran, where Depastrum cyathiforme had also been found, e.g. pools trapped by east / west running ledges, and dykes that run horizontally with the shoreline. The GPS data for this pool is as follows 54.075333° N 4.68526° W.
How anyone can be deflated, excited, optimistic and driven is beyond me, and I definitely think by this time I was running on adrenalin but on getting to the second site, to the west of Poolvash Farm, I got a real buzz from the habitat I found. A case of keeping calm and careful, again masses of Egg wrack to deal with under foot before even getting to the pool. The habitat was very good indeed, a middleshore pool with narrow exit, surrounded by a high reef, the exit potentially trapping species within the pool, species such as the one being looked for. The pool largely contained Egg wrack around it's northern rim and Fucus serratus, Saw wrack was found within the pool with patches of Bifurcaria bifurcata, Brown tuning fork weed; on submerged rocks. P.H. Gosse reported Depastrum cyathiforme from under Saw wrack covered rocks at Weymouth in the 1850s. More time and better light would have been an advantage but it was soon obvious that many of the smaller species of algae in the pool were in a state of decay, you could see it and smell it, and this is definitely something stauromedusae dislike completely, so it was a case of going through the motions just in case, and not giving up hope, there was after all, always tomorrow!
One species was found at Poolvash that was so small, possibly just over 1mm diameter, that photography proved very difficult indeed, the species has yet to be properly identified and it has been suggested by Marco Faasse that it could be a species of juvenile starfish, it's arrangement into 5's would certainly appear to be quite distinctive. I'm sure someone one day will tell me what the species is, although I guess the most logical suggestion is that the images may possibly be of metamorphosizing juveniles of the genus Asterina, the Cushion star. See close-up.
Sadly shortly after visiting Poolvash I became unwell, because of a change in the weather, and I had to miss the following mornings low tide. Some sufferers of CFS/ME are super sensitive to certain sounds or smells, unfortunately my sensitivity is to approaching weather fronts and areas of low pressure, so a second opportunity to visit Poolvash was missed. I felt quite sad about this because I was really looking forward to finding Depastrum cyathiforme, if possible, in 'The Pool of Death', and finding it there would also provide a very strong headline for courting additional publicity for the species. Fortunately I was well enough later the next day to look at a site called 'The Ledges' at Port St. Mary and not diverge from my original plan of action. Of course the rights and wrongs of diverting from the original plans could be discussed, and there might have been a need for some flexibility. However, a paper plan was left in full sight in my hotel room, and both the Fisheries Department and Manx Wildlife Trust knew where I would be at any point in time, in case anything did go wrong. At the end of the day, having not found the species thus far at known locations, finding Depastrum cyathiforme would be down to luck, and being at the right place at the right time. Searching a new site that appeared suitable for it might appear to be the right thing to do.
Afternoon and Evening 16th July 2014
The Ledges at Port St Mary, 54.06718° N 4.73576° W, image taken at low water. The site recommended to me by Peter Duncan of the Isle of Man Department of Fisheries. On looking at the site using Google Earth the geology of the site appeared geologically similar to the type of shore at Weymouth, where P.H. Gosse had found Depastrum cyathiforme in the mid-19th century.
On talking to people, it appears the site is one of the most studied sites on the island in terms of its marine biology, although Depastrum cyathiforme had never been reported there. I wasn't that bothered by this as I'd found colonies of stauromedusae on well surveyed sites before, so often are sites studied during fine and favorable weather during the summer that fauna occurring during the late autumn and winter is often overlooked. Of course looking for a single species allows one to concentrate on looking in very specific areas and habitats. I am pleased to say that the site looked more like a Cornish shore than any previously visited and I was glad I didn't have to stand on a single strand of Egg wrack as I proceeded down the shore! Parking was free and access extremely easy, apart from the extreme lowershore it is one of the easiest shores to get around on that I've ever been, I'm speaking in terms of the limestone ledges themselves, the site has on either side two boulder fields, which could prove equally good habitat for Depastrum cyathiforme. There was no plan to search the underboulder communities either side of the ledges, something I will have to leave to someone else; but the whole shore here at Port St. Mary would appear to provide good habitat for finding Depastrum cyathiforme, and given the site is between the reported sites at Port Erin and Poolvash there's no reason to suspect it will not be found there.
I would say there would only be one reason for the species not occuring there and that would be a decline. However, we know nothing about the life cycle of Depastrum cyathiforme at all, and it might be likely that the species has only been observed when it has occured on the shore in very large numbers. It is possible that the species may not be an intertidal species, but that it occurrs intertidally when settlement has occurred intertidally, e.g. by wind and or tide, an apparent bloom; juveniles becoming mature where they find favorable habitat. If this is the case finding the species intertidally may be more akin to winning a lottery, records might suggest this, but it only by looking for the species and studying it when and where it is found that we'll ever find out. The species was recorded at Port Erin in 1892 and 1893 and reported as abundant but local, it may be assumed that small areas of shore are important in supporting good populations, if this is the case it is quite a cause for concern and might be suggestive of a species that is potentially vulnerable to changes in habitat and environmental conditions. Hopefully one day the species will be found and better understood. There was no evidence to suggest that the species was local at Port Erin as it wasn't found, the habitat there being search quite systematically for it, perhaps July is too late in the year, or too late just this year. There is one thing I am sure of, the frequency and severity of the winter storms of 2013/14 have had a dramatic affect on intertidal flora and fauna.
I visited the ledges shortly after high water and slowly followed the tide down. Marine splash midges (flies of the family Chironomidae), springtail (Anurida maritima), mites and molluscs were observed in the splash zone. A 2mm long adult beetle, possibly of the genus Ochthebius, was observed diving in shallow splash zone pool containing decaying algae. Floating coleoptera larvae were also noticed in the same small pool.
Following the tide out much emphasis was placed on finding stauromedusae amongst algae, and despite it not being the right time of year to find many, if any, as stauromedusae are found usually from late August / September to April / early May; June, July and August are often barren months. No stalked jellyfish were found on the day but the ebbing tide revealed what can only be described as some of the most amazing habitat I've seen on a shore, the geology is quite remarkable.
Of course, I'm now on my third and last day of searching for Depastrum cyathiforme, and all I'm taking notice of is anything that might relate to it, either in terms of associated species, such as certain species of stalked sea squirts, or habitat to look on or under, including algae covered rocks, under algae on overhangs, or within crevices.
I have largely concentrated on taking images of the habitat of this site rather than of incidental finds, because I was largely too busy looking for a single species, and time was running out to focus on anything else and I daren't be distracted! Not that it ultimately mattered. I was surprised to come across the anemone Sagartia elegans under two layers of rocks, and rather interestingly, it had caught an amphipod.
In all, I completely enjoyed my stay on the Isle of Man and have to thank those who helped with my visit at the Department of Fisheries and the Manx Wildlife Trust. It's just a shame I was unable to meet my objective, but I enjoyed trying and hope to return to the island for another look, if all else fails.
A short conclusion
A shame Depastrum cyathiforme wasn't found on the Isle of Man during my visit there, but I hope the visit will promote the species there in some way, and that this may lead to its future discovery. I must thank everyone that has helped with my visit and who have made it so enjoyable. A lot of research was done prior to the visit and the time undertaking it will not be wasted, as I hope to return and try again, perhaps at a time I find the species elsewhere in the UK.
David Fenwick 24.07.14
Also see - NOTE on LUCERNARIANS, Port Erin, Isle of Man. W. I. Beaumont. 1893.
