Eunicella verrucosa

Researched By	Dr Keith Hiscock	Data Supplied By	MarLIN
Refereed by	This information is not refereed.
Taxonomy
Scientific name	Eunicella verrucosa	Common name	Pink sea fan
MCS Code	D611	Recent Synonyms	None
Phylum	Cnidaria	Subphylum
Superclass	Anthozoa	Class	Octocorallia
Subclass		Order	Gorgonacea
Suborder		Family	Plexauridae
Genus	Eunicella	Species	verrucosa
Subspecies
Additional Information	May be confused with Swiftia pallida, which occurs in Scotland northwards to Scandinavia but is much less branched, has generally thinner branches and may be white or rose coloured.
Taxonomy References	Howson & Picton, 1997, Manuel, 1988
General Biology
Growth form	Arborescent / Arbuscular	Feeding method	Passive suspension feeder
Mobility/Movement	Permanent attachment	Environmental position	Epibenthic, Epifaunal
Typical food types	Suspended matter including plankton	Habit	Attached
Bioturbator	Not relevant	Flexibility	High (>45 degrees)
Fragility	Intermediate	Size	Medium-large(21-50cm)
Height	25-50 cm	Growth Rate	10 mm/year
Adult dispersal potential	None	Dependency	Independent
Sociability	Colonial	Host for	Tritonia nilsohdneri, Amphianthus dohrnii, Simnia patula.
Toxic/Poisonous?	No
Additional Information	The sea fan anemone Amphianthus dohrnii specifically lives on sea fans. The sea slug Tritonia nilsohdneri feeds on sea fans and is camouflaged to look like the sea fan. The 'poached egg shell' Simnia patula feeds on sea fans and observations at Lundy (K. Hiscock, R. Irving pers. comm.) suggest that their egg laying might cause mortality (see 'Additional Information' in Adult Sensitivity). Other species colonize damaged or partially dead sea fans where the coenenchyme has been lost, especially barnacles, bryozoans and ascidians.
Biology References	Anonymous, 1999(l)
Distribution and Habitat
Distribution in Britain & Ireland	Recorded northwards to north Pembrokeshire and eastwards to Portland Bill in Britain. Common in parts of south Devon and Cornwall and at Lundy. Present on the south and west coasts of Ireland but common only in Galway and Donegal Bays.
Global distribution	South and west coasts of Britain and Ireland south to north-west Africa and present in the western Mediterranean (Carpine, 1975; Manual, 1988).
Biogeographic range	Not researched	Depth range	4m to at least 50m
Migratory	Non-migratory / Resident
Distribution Additional Information	Older records suggest that the species occurred in the English Channel almost to the Thames Estuary (Margate). May occur in south-west Scotland but records needed (Manual, 1988)
Substratum preferences	Artificial (e.g. metal/wood/concrete), Bedrock, Large to very large boulders	Physiographic preferences	Open coast, Offshore seabed, Strait / sound
Biological zone	Upper Circalittoral, Lower Circalittoral	Wave exposure	Very Exposed, Moderately Exposed, Exposed, Sheltered
Tidal stream strength/Water flow	Moderately Strong (1-3 kn)	Salinity	Full (30-40 psu)
Habitat Additional Information
AMBI Group (Borja et al., 2000)	I
Distribution References	Carpine & Grasshoff, 1975, Anonymous, 2001, Manuel, 1988, Bavestrello et al., 1997
Reproduction/Life History
Reproductive type	Insufficient information	Developmental mechanism	Lecithotrophic
Reproductive Season	Insufficient information	Reproductive Location	Insufficient information
Reproductive frequency	Annual episodic	Regeneration potential	No
Life span	21-100 years	Age at reproductive maturity	Insufficient information
Generation time	Insufficient information	Fecundity	Insufficient information
Egg/propagule size	Insufficient information	Fertilization type	Insufficient information
Larvae/Juveniles Larval/Juvenile dispersal potential 100-1000m Larval settlement period Insufficient information Duration of larval stage Not relevant
Additional Information	The age of Eunicella verrucosa colonies can be determined (destructively) from growth rings in the axis. There is one growth ring per annum as evidenced by studies that measured growth rate in marked fans and then harvested the sea fans to count growth rings (Keith Hiscock, unpublished studies). Growth rate can be highly variable with an increase in branch length of up to 6 cm in some branches in one year and virtually none in others in Lyme Bay populations (C. Munro, pers. comm.) in one year. About 1 cm per annum increase in branch length was recorded in marked colonies at Lundy corresponding to measures of branch length correlated with number of annual growth rings (Keith Hiscock, unpublished studies, see above). There is no specific information on reproduction in Eunicella verrucosa but observation of the occurrence of small colonies suggests that production and settlement of larvae is successful in occasional years in south-west Britain. The larvae are most likely lecithotrophic and have a short life. Colonies seem to take some time if ever to colonize wrecks that are distant (>1 km) from existing populations. For the morphologically similar Paramuricea clavata in the Mediterranean, Coma et al. (1995) described reproduction and the cycle of gonadial development with spawning occurring 3-6 days after full or new moon in summer. Spawned eggs adhered to a mucus coating to female colonies: a feature that would be expected to have been readily observed if it occurred in Eunicella verrucosa. Maturation of planulae took place among the polyps of the parent colony and, on leaving the colony, planulae immediately settled on surrounding substrata. It seems more likely that planulae of Eunicella verrucosa are released immediately from the polyps and are likely to drift.
Reproduction References	Coma et al., 1995