Sea Anemones

 
 
 
 GENERAL
 Sea Anemones
 Movement
 Feeding
 Predators
 Diagram

 
 
ANIMALIA

 
 Placozoa 
 Porifera
 Cnidaria
 Ctenophora
 Mesozoa
 Platyhelminthes
 Nemertina
 Gnathostomulida
 Gastrotricha
 Rotifera
 Kinorhyncha
 Loricifera
 Acanthocephala
 Entoprocta
 Nematoda
 Nematomorpha
 Ectoprocta 
 Phoronida 
 Brachiopoda 
 Mollusca 
 Priapulida 
 Sipuncula 
 Echiura 
 Annelida 
 Tardigrada 
 Pentastoma 
 Onychophora 
 Arthropoda 
 Pogonophora 
 Echinodermata
 Chaetognatha
 Hemichordata 
 Chordata

 
CNIDARIA

 
 
 
 
 
 
 
 

 

British Marine Life Study Society

  Beadlet Anemone 
 
Common Name(s):
 Beadlet Anemone
Scientific Name:
 Actinia equina
Family:
Usual Size: 
    25 mm
(base diameter) 
                      Photographs by Andy Horton
Identification:
Colours: red, green, brown. 

The blue beads (acrorhagi) are always present at the top of the column underneath the tentacles. Occasionally they are white or off-blue. 

 The green variety is sometimes known as Actinia prasina.

Similar species:   Actinia fragacea , Anthopleura ballii
 

Breeding: 

Viviparous.  Young approx. 12 -100 


 Beadlet Anemone, Actinia equina, spurting out a young anemone.

The best explanation of their reproduction is by parthogenesis. However, the author of this piece (Andy Horton) considers the likelihood that they break off internally (a bit like internal basal laceration) to be a  possibility. No evidence of sexual reproduction has been observed despite extensive study. 

Spring 2000: You remember the big Beadlet you gave me ages ago ? Came downstairs this morning and found it has literally exploded...there are hundreds of tiny anemones everywhere in the tank, all over the parent, the rocks, pumps..they are everywhere. I've never seen one do that before, the other ones I've had have normally given birth to a few at a time, not like this one. The parent seems to be OK, a bit shrunken and lumpy, but otherwise fine

Beadlet Anemone with lots of babies about to spurt out (July 2003)
Photograph by David Hallett via the Wet Thumb Smart Group


Habitat:
Intertidal. 
 

Beadlet Anemones with their tentacles retracted.
Beadlet Anemones with their tentacles retracted.
 
Food:
Mussel flesh, small crustaceans (copepods, larvae), fragments and whole larger (dead) crustaceans, worms. Small crabs, especially the Shore Crab

Biogeographical Range:
NE Atlantic, Arctic-tropics (salinity over 2.8% only, absent from the Baltic). 
Temperature range 2º C - 28º C. 
Bionomics: 

Additional Notes:
In captivity, this anemones has been changing colour, over a long period of time (about one month). The notes have been lost, but the anemone either changed from red to green through an intermediate brownish stage or vice-versa. 

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.

Double-headed specimens can occur

Neither "catch tenctacles" or acontia have been observed in this species. 

"Sir John Dalyell at his time kept a well-known specimen of Actinia equina named "Granny" in captivity for decades and at his decease Charles Peach inherited the animal, which in this way happened to live in Edinburgh for more than 50 years, so at least certain species seem to be able to have a very long potential life span." 
(from Hans.G.Hansson@TMBL.GU.SE **** Tjaernoe Marine Biological Lab. ****
http://www.tmbl.gu.se   Phone: +46 526 686 36   Fax: +46 526 686 07
Personal home page: http://www.tmbl.gu.se/staff/HansGHanssonP.html  )

More Information Link

Time lapse of the anemone crawling (External site) http://www.nhm.ukans.edu/~inverts/

Stripes occur on both red and green specimens. The blue acrorhagi can be seen clearly in this Sussex specimen. 

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. 
Shorewatch Project

Cnidaria Web Site (World)

 

FIVE KINGDOMS TAXONOMIC INDEX TO BRITISH MARINE WILDLIFE
 Copyright 1997-2003   British Marine Life Study Society
Homepage
Index
News 2009
News 2008
Main Links
Membership Form
Top of the Page
 

AcrorhagiAcrorhagiAcrorhagiAcrorhagiAcrorhagiAcrorhagiAcrorhagi