Protanthea simplex

Researched By	Angus Jackson	Data Supplied By	MarLIN
Refereed by	Dr Ib Svane
Taxonomy
Scientific name	Protanthea simplex	Common name	Sealoch anemone
MCS Code	D668	Recent Synonyms	None
Phylum	Cnidaria	Subphylum
Superclass	Anthozoa	Class	Hexacorallia
Subclass		Order	Actiniaria
Suborder	Protantheae	Family	Gonactiniidae
Genus	Protanthea	Species	simplex
Subspecies
Additional Information	No text entered
Taxonomy References	Howson & Picton, 1997, Carlgren, 1921, Manuel, 1988
General Biology
Growth form	Cylindrical	Feeding method	Passive suspension feeder
Mobility/Movement	Temporary attachment	Environmental position	Epifaunal
Typical food types	Insufficient information	Habit	Attached
Bioturbator	Not relevant	Flexibility	High (>45 degrees)
Fragility	Fragile	Size	Small(1-2cm)
Height	Up to 2 cm	Growth Rate	Insufficient information
Adult dispersal potential	Insufficient information	Dependency	Independent
Sociability	Solitary
Toxic/Poisonous?	No
Additional Information	This species exhibits an unusual collapse behaviour, where at intervals, muscle tone is rapidly lost and the animals hangs limply from its disk attachment. This is considered to be an egestion process rather than a feeding, alarm or escape response. Despite the primitive musculature, Protanthea simplex is capable of active movement. In Sweden Protanthea simplex has been recorded historically at densities of up to 2000 per square metre. Svane & Gröndal (1988) reported that the species was abundant below the algal belt in semi-sheltered and sheltered sites in the Gullmarsfjorden, Sweden (10.7 % and 4.5 % cover per 0.25 square metre respectively). This contrasted with earlier work by Gislén, undertaken between 1926-29, where the species was not recorded in the semi-sheltered sites and only made up a small proportion of the total wet weight of species in the sheltered sites (Svane & Gröndal, 1988).
Biology References	McFarlane, 1985, Nyholm, 1959, Carlgren, 1893, Carlgren, 1921, Manuel, 1988, Svane & Groendahl, 1988
Distribution and Habitat
Distribution in Britain & Ireland	From the northern Firth of Clyde all along the west coast of Scotland, particularly in sea lochs. Not recorded in Orkney or Shetland. Recently (June 2006) found in Killary Harbour, Connemara.
Global distribution	Killary Harbour (Connermara, Galway), Western Scotland out to Rockall Bank, round the coasts of the Skagerrak and northern Kattegat, Norway.
Biogeographic range	Not researched	Depth range	9m to at least 500m
Migratory	Non-migratory / Resident
Distribution Additional Information	None entered
Substratum preferences	Bedrock, Biogenic reef, Large to very large boulders, Small boulders	Physiographic preferences	Strait / sound, Sealoch, Offshore seabed
Biological zone	Lower Infralittoral, Upper Circalittoral, Lower Circalittoral	Wave exposure	Sheltered, Very Sheltered, Extremely Sheltered, Ultra Sheltered
Tidal stream strength/Water flow	Weak (<1 kn), Very Weak (negligible)	Salinity	Full (30-40 psu), Variable (18-40 psu)
Habitat Additional Information	None entered
Distribution References	Nyholm, 1959, Carlgren, 1921, Manuel, 1988
Reproduction/Life History
Reproductive type	Gonochoristic	Developmental mechanism	Lecithotrophic, Oviparous
Reproductive Season	September to October	Reproductive Location	Water column
Reproductive frequency	Annual episodic	Regeneration potential	Yes
Life span	Insufficient information	Age at reproductive maturity	Insufficient information
Generation time	Insufficient information	Fecundity	Insufficient information
Egg/propagule size	Insufficient information	Fertilization type	External
Larvae/Juveniles Larval/Juvenile dispersal potential >10km Larval settlement period Insufficient information Duration of larval stage 11-30 days
Additional Information	At 10-12 °C the larvae spend 15-20 days in the plankton before settling. In Sweden breeding occurs in September and October. Breeding terminates earlier in shallower water. Fertilization of the eggs occurs in the water column. The reproductive organs are white or orange- pink. Fragments of tissue in this species (except the tentacles) are capable of regenerating into complete anemones, a form of vegetative, asexual reproduction (Manuel, 1988). Apart from Protanthea simplex, the only other species in the family Gonactinidae is Gonactinia prolifera. Gonactinia prolifera is unique in that the planula larva carries 'collar cells' similar in structure to the choanocyes of sponges and it is possible that Protanthea simplex has similar cells (I. Svane, pers. comm.). These secretory cells contain yolk granules and are undoubtedly involved in the formation of the fibrous coating of the planula which is again a unique feature of its planula (Chia et al, 1989).
Reproduction References	Nyholm, 1959, Carlgren, 1921, Chia et al., 1989