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.
The site at Marazion Harbour is gently sloping and is north and part of the extensive reef system that occurs east of Marazion Causeway. This reef, only partly exposed on the lowest low tides of the year has been found to be extremely biodiverse. It occurs in relatively shallow water and has at least two Eelgrass beds, the area is also protected from storms by St. Michael's Mount. The reef is mentioned here because we saw an unprecedented number of severe storms during the winter of 2013/14. The area from Great Hogus to The Greeb, to the east of Mounts Bay, appears to have the highest frequency of stauromedusae in Mounts Bay and just four weeks after the last severe storm, the Valentine's Day storm. The Surfhog buoy measured a 90.9ft wave off Penzance during the St. Valentine's Day storm. The site in front of Marazion Harbour might just be one of the most protected areas, which is why so many stauromedusae were observed in March 2014.
Possibly the easiest way to try and explain the local recent distribution is by comparing Mounts Bay with a bottle of traditional lemonade. If you violently shake the bottle (storms) all the bits of fruit are found throughout the liquid, the fruit (stauromedusae), then begin to settle at the bottom of the bottle after the agitation stops. It is likely here that stauromedusae may have settled in a more protected area first, an area where there is less water movement. The protection afforded by St. Michael's Mount also preventing damage to algae on which stauromedusae depend. At more wave exposed sites, algae on which stauromedusae depend have been severely cropped, or removed completely.
Marazion Harbour was surveyed on the 18.03.14, with Top Tieb surveyed 19.03.14. The first record on the 18th and last record on the 19th are used here to give a rough distance of the extent of the bloom. The bloom has been estimated to cover approximately 282m of shore. It could have extended over 400m.
Site and habitat images
Lowershore pools below Marazion Harbour 18.03.14. -1
Lowershore pools below Marazion Harbour 18.03.14. -2
Higher pools below Marazion Harbour 18.03.14. -1
Higher pools below Marazion Harbour 18.03.14. -2
Marazion Harbour, Marazion, records SW 5193 3040.
18.03.14. 48 specimens. 28 Calvadosia cruxmelitensis and 20 Haliclystus octoradiatus on a small area of shore in front of Marazion Harbour. Stauromedusae initially found in a series of three fairly shallow lower / middleshore pools running east -west across the shore (see images of 'higher pools' above), and after, in smaller pools on the lowershore. The smaller pools nearer the low tide mark were chosen for searching because of recent observations; more stauromedusae had been found closer to the low tide mark than anywhere else. The disadvantage being the limited amount of time in which to search. Chondrus crispus was 'the' most frequent, favorable, species of algae and occured both on rocks and bedrock, both in and out of pools. Weather, cloudy but bright, windy; high pressure. 12.23pm low water. 0.7m low. Ref. Cornish Coast tide times 2014. Record by David Fenwick.
Calvadosia cruxmelitensis 1
Specimen on Corallina officinalis in pool at SW 51927 30420.
Calvadosia cruxmelitensis 2
Specimen on Chondrus crispus in pool at SW 51932 30424.
Calvadosia cruxmelitensis 3
Specimen on Chondrus crispus in pool at SW 51930 30429.
Calvadosia cruxmelitensis 4
Specimen on Chondrus crispus in pool at SW 51934 30427.
Calvadosia cruxmelitensis 5
Specimen on Chondrus crispus in pool at SW 51934 30427.
Calvadosia cruxmelitensis 6
Specimen on Chondrus crispus in pool at SW 51943 30431.
Calvadosia cruxmelitensis 7
Specimen in pool at SW 51943 30431.
Calvadosia cruxmelitensis 8
Specimen on Chondrus crispus in pool at SW 51947 30414.
Calvadosia cruxmelitensis 9
Specimen on Chondrus crispus in pool at SW 51973 30420.
Calvadosia cruxmelitensis 10
Specimen on Chondrus crispus in pool at SW 51973 30420.
Calvadosia cruxmelitensis 11
Specimen on Chondrus crispus in pool at SW 51973 30420.
Calvadosia cruxmelitensis 12
Specimen on Chondrus crispus in pool at SW 51973 30420.
Calvadosia cruxmelitensis 13
Specimen on Chondrus crispus in pool at SW 51960 30411.
Calvadosia cruxmelitensis 14
Specimen on Chondrus crispus in pool at SW 51960 30411.
Calvadosia cruxmelitensis 15
Specimen on Chondrus crispus in pool at SW 51960 30411.
Calvadosia cruxmelitensis 16
Specimen in pool at SW 51960 30411.
Calvadosia cruxmelitensis 17
Specimen on Chondrus crispus in pool at SW 51954 30388.
Calvadosia cruxmelitensis 18
Specimen in pool at SW 51951 30394.
Calvadosia cruxmelitensis 19
Specimen on Chondrus crispus in pool at SW 51952 30386.
Calvadosia cruxmelitensis 20
Specimen on Chondrus crispus in pool at SW 51952 30386.
Calvadosia cruxmelitensis 21
Specimen on Chondrus crispus in pool at SW 51948 30386.
Calvadosia cruxmelitensis 22
Specimen on Chondrus crispus in pool at SW 51948 30386.
Calvadosia cruxmelitensis 23
Specimen in pool at SW 51935 30386.
Calvadosia cruxmelitensis 24
Specimen on Chondrus crispus in pool at SW 51933 30395.
Calvadosia cruxmelitensis 25
Specimen on Chondrus crispus in pool at SW 51933 30395.
Calvadosia cruxmelitensis 26
Specimen on Chondrus crispus in pool at SW 51933 30395.
Calvadosia cruxmelitensis 27
Specimen on Chondrus crispus in pool at SW 51933 30396.
Calvadosia cruxmelitensis 28
Specimen on Chondrus crispus in pool at SW 51955 30432.
Haliclystus octoradiatus 1
Specimen on Chondrus crispus in pool at SW 51919 30416.
Haliclystus octoradiatus 2
On Furcellaria lumbricalis in pool at SW 51927 30420.
Haliclystus octoradiatus 3
Specimen on Chondrus crispus in pool at SW 51930 30429.
Haliclystus octoradiatus 4
Specimen on Chondrus crispus in pool at SW 51930 30429.
Haliclystus octoradiatus 5
Specimen on Chondrus crispus in pool at SW 51934 30427.
Haliclystus octoradiatus 6
Specimen on Chondrus crispus in pool at SW 51934 30427.
Haliclystus octoradiatus 7
Specimen on Chondrus crispus in pool at SW 51943 30431.
Haliclystus octoradiatus 8
Specimen on Chondrus crispus in pool at SW 51943 30431.
Haliclystus octoradiatus 9
Specimen on Chondrus crispus in pool at SW 51943 30431.
Haliclystus octoradiatus 10
Specimen on Chondrus crispus in pool at SW 51973 30420.
Haliclystus octoradiatus 11
Specimen on Chondrus crispus in pool at SW 51973 30420.
Haliclystus octoradiatus 12
Specimen on Chondrus crispus in pool at SW 51960 30411.
Haliclystus octoradiatus 13
Specimen on Chondrus crispus in pool at SW 51951 30394.
Haliclystus octoradiatus 14
Specimen on Chondrus crispus in pool at SW 51947 30394.
Haliclystus octoradiatus 15
Specimen on Chondrus crispus in pool at SW 51948 30386.
Haliclystus octoradiatus 16
Specimen on Chondrus crispus in pool at SW 51948 30386.
Haliclystus octoradiatus 17
Specimen on Chondrus crispus in pool at SW 51948 30386.
Haliclystus octoradiatus 18
Specimen on Chondrus crispus in pool at SW 51933 30395.
Haliclystus octoradiatus 19
Specimen on Chondrus crispus in pool at SW 51933 30395.
Haliclystus octoradiatus 20
Specimen on Chondrus crispus in pool at SW 51955 30432.
This part of the website is "UNDER CONSTRUCTION", details and text may be unchecked. Adding profiles and records for each site can be quite time consuming, especially during periods of recording.
