Identification:
Snakelocks Anemones, Anemonia viridis,
are found on the southern and western shores of Britain and as far
south as the Mediterranean Sea. They are distinguished by long flowing
tentacles and will usually be found in a bright green colour, sometimes
with purple tips to the tentacles. A few specimens have a scarlet
on their tentacles.
The anemone contains a symbiotic algae called zooxanthellae
that are found in the anemone's tissues. These algae are necessary for
the long term survival of the sea anemone. When the numbers of algae diminish
the anemone may appear dull grey in colour. The algae need light to flourish,
so Snakelocks Anemones will be found in the sunniest pools. Unlike Beadlet
Anemones, they do not readily retract their tentacles if left stranded
on land by the retreating tide. However, in aquaria they demonstrate their
ability to do so.
Correction: the green
colour is because of a green
fluorescent protein, common in corals, sea anemones, and some other
cnidarians.
Snakelocks Anemone can capture small fish and other animals in their stinging
tentacles.
Snakelocks
Anemone under Worthing Pier 2003
Similar species: Actinia
equina (green)
Breeding:
Longitudinal Fission. Anemone splits into
two identical halves, as illustrated (click on the link below). The process
can take from between 5 minutes and 2 hours.
Pairs can often be seen on the shore in spring.
Discussion on division of this anemone is on the
British Marine Wildlife
Forum (commenced 1 August 2000)
Group Home: http://uk.groups.yahoo.com/group/Glaucus
You have to join (its FREE) and
then search under the scientific name of the anemone %/or Longitudinal
Fission.
Photograph
Habitat:
Intertidal pools and shallow water. Requires high intensity light levels
(e.g. 50000 Lux is natural in summer, 16000 Lux will probably suffice in
aquaria) for the zooxanthellae symbiotic algae in its tissues.
Aquarium Lighting (notes)
Nature Photography
(including LUX readings conversion)
http://www.fredparker.com/ultexp1.htm
Food:
Tissues contain zooxanthellae
symbiotic algae which appears to be necessary for the long term survival
of this sea anemone. Ingests larger food items both dead and alive, e.g.
small fish, just moulted palaemonid prawns. Gastropod molluscs and all
sorts of crustaceans form the bulk of the diet in limited studies.
Commensals:
8
October 2011
The
Snakelocks
Anemone Shrimp, Periclimenes
sagittifer, has now been discovered in Babbacombe
Bay, south Devon. This sea anemone is
symbiotic with the Snakelocks Anemone,
Anemonia
viridis.
They
were first discovered around
mainland Britain under Swanage
Pier
in 2007. Before
this report, the most northerly sightings were regular reports from around
the Channel
Islands.
Terry
Griffiths Underwater Photography
22
September 2007
Numerous
Snakelocks
Anemone Shrimp, Periclimenes
sagittifer, were found during a dive off Swanage
Pier
in Dorset. These small colourful shrimps look blue amongst the green tentacles
of the sea anemone. They can reach about 30 mm
in size and usually live symbiotically with the Snakelocks
Anemone, Anemonia viridis.
This is the first known sighting of Periclimenes
sagittifer in the shallow seas around
mainland Britain.
Before
this report, the most northerly sightings were regular reports from around
the Channel
Islands.
Stinging Tentacles:
When poked with fingers the tentacles feel incredibly
sticky to the thick skin. However, when grazed on by the abdomen the tentacles
can sting and raise a rash, which can last a month. There have been
several reports in 1999. This anemone was responsible for a severe blistering
of a baby's leg on a Guernsey beach in August 1999. The sting can be worse
than that of the jellyfish around Britain.
"I got stung by something caught up in a thick
canopy of Sargassum at Kimmeridge, Dorset, in July 1999 - it bubbled up
like a severe nettle sting, then turned red as it subsided to leave red
weals which I still have a trace of on my stomach (over a month later).
I guess it was an unusual reaction to Common Jellyfish as I didn't see
any Cyanea that day."
I hope this is helpful
Richard Harrington
MCS (received September 1999)
"Swimming in Chesil Fleet through' some Sargassum,
I felt a mild tingling sensation across my abdomen. This was caused by
Snakelocks Anemone!
The scars from the weals lasted for a couple
of years ! Obviously, the skin on fingers is too thick to be vulnerable."
Bill Farnham (Univ. of Portsmouth) (received
September 1999)
A snorkeller was stung on the soft skin on the
underside of her forearm producing a large red weal after diving at Kimmeridge,
Dorset. After 6 weeks the weal had almost disappeared, but it still itched.
Jane Lilley (Newdigate, Surrey) (received
September 1999)
I received a sting and a rash on my arm when
swimming off Worthing. (received February 2000)
Link
to possible injury by this sea anemone
I remember years ago seeing a boy messing about
with these anemones and developing a sudden and painful line of weals on
his inner arm. (Peter Glanvill).
Stinging Jellyfish
Link
This
rash on a young girl came after playing in a rock pool.
Report:
I was recently in the Purbecks in Dorset and whilst
my daughter was swimming in a rock pool (at Dancing Ledge) she was suddenly
stung by 'something'!! There were no jelly fish in sight and we weren't
sure what caused it. The sting was very painful and when it eased off,
very itchy! Just after she was stung, the marks on her arm and leg were
similar to those you get when stung by stinging nettles ( raised and white
blotches). The marks, as shown in the attached picture, are now raised
and red with 'a kind of tickly feeling' when touched. Could this be some
kind of stinging seaweed?? Is there such a thing in the coastal waters
off the UK?
Stings from Dorset
Dear Shorewatchers!
I am writing to inform you of a recent incident with Snakelocks
Anemone. I was badly stung all over my back and bottom a week
ago whilst in a rock pool at Dancing
Ledge in Dorset, part of the Purbeck Coastline in the south west of
England.
There is a particular rock pool that was artificially created by a headmaster
of a local boarding school sometime in the early 20th century. It forms
a perfect intertidal swimming pool that attracts lots of families and bathers
like myself. I was in the pool for some time leaning and sitting on the
edges. I did feel a small sting quite early on but thought it was an open
cut or graze from scrambling on the rocks before getting in.
After a long swim in the sea as well, I got out and immediatley felt
a rapid burning sensation like my skin was on fire. The area bubbled up
in patches, very similar to a dense collection of nettle stings. Interestingly,
the stings on my bottom form a neat and rather unattractive line on the
edge of my bikini bottoms. There were other people in the water at the
same time but they had long shorts on or wetsuits, so the stings couldn't
penetrate. I did hear from another swimmer that a little girl who was only
wearing a bikini like me, had also suffered an attack.
I took the attached photo about ten minutes after getting out of the
water. The area remained very hot and very very tender for about two days.
During the following week it began to go down then it formed in red welts
that look like chronic eczema.
It's become itchy and inflamed and I started to use calamine lotion again
to sooth it. I hope that you will publish the photos and the story to warn
people, particularly with young children, that this rock pool has a large
concentration of Snakelock Anemones.
Do you know if there is a risk of scarring from such attacks? I sincerely
hope not!
I very much look forward to hearing form you. Please let me know if
you require any further information.
Sting
Pain Index
Range:
South & west of the British Isles. Mediterranean and the Atlantic
coasts of Portugal, France, Spain.
Most easterly point found regularly on the northern coast of the English
Channel, is Worthing, Sussex.
Additional Notes:
In the wild, this species will not retract its tentacles, although
in captivity it has been shown to be able to do so.
Sea Anemones fight over territory. The red Beadlet
Anemone, Actinia equina uses its acrorhagi (blue beads)
and the green Snakelocks Anemone, Anemonia viridis uses its long
tentacles. pic.
Neither "catch tentacles" or acontia have been observed in this species.
Ref: Simon Davy, Zooxanthellae in the tissues of British sea anemones
(Coelenterate Society talk at the School of Ocean Sciences, University
of Wales, Bangor).
Commensals:
Small long-legged spider crabs hide beneath the
tentacles of this sea anemone, as well as the prawn Perciclimenes sagittifer.
Photographs can be found on the following site. Click on the logo.
Reports:
Results collected from an Exposed Shore, West Angle Bay (SM
853 033),
Pembrokeshire, Wales
Lower Shore, Average coverage= 3.2/meter square
Average Size= 32.9
mm diameter (along the longest axis)
Middle Shore, Average Cover= 1.8/meter square
Average Size= 29.0 mm diameter (along the longest
axis)
Andrew Flatt
Meadfoot, south Devon, on a previous occasion the middle shore
numbers were about 50 per square metre, in places the edges of the small
pools were continuous Anemonia viridis effectively preventing anything
else living in the pools.
Meadfoot is a rocky outcrop in the middle of a sandy beach.
Andy Horton
1 August 2000
A most unusual appearance on Kingston Beach
was a solitary Snakelocks Anemone, which reach their most easterly point
of distribution up the English Channel (northern coast) at Worthing,
with an occasional stragglers on the shore at Shoreham, and almost entirely
absent from Brighton.
Andy Horton.
19 September 2001
In my aquarium a small Snakelocks Anemone, Anemonia
viridis, has a basal diameter of 20 mm and a long tentacle stretching
out of 210 mm.
Andy Horton.
Link to Smart Groups British Marine Wildlife
Discussion Page on Anemonia viridis
NB: The two anemones in the foreground of the main
photograph are Anthopleura ballii.
Information wanted: Please send any records of this sea anemone,
with location, date, who discovered it, how it was identified, prevalence,
common name and any other details to:
Shorewatch
Project EMail Glaucus@hotmail.com.
All messages will receive a reply.
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