BIOTIC

BIOTIC Species Information for Metridium senile

Researched by

Dr Keith Hiscock & Emily Wilson

Data supplied by

MarLIN

Refereed by

This information is not refereed.

Taxonomy

Scientific name

Metridium senile

Common name

Plumose anemone

MCS Code

D710

Recent Synonyms

None

Phylum

Cnidaria

Subphylum

Superclass

Anthozoa

Class

Hexacorallia

Subclass

Order

Actiniaria

Suborder

Nynantheae

Family

Metridiidae

Genus

Metridium

Species

senile

Subspecies

Additional Information

Manuel (1988) describes two distinctive varieties. Var. dianthus is large with a tall column when expanded. The disc is deeply waved or folded. The many tentacles give a 'fluffy' appearance. Individuals may be 30 cm in height, with a basal diamer and tentacle span of 15 cm or more. Var. pallidus is a small form not exceeding 2.5 cm across the base with a flat disc without folds. Bucklin (1985) investigated biochemical genetic variation and concluded the presence of two morphs of Metridium senile but that they were variants resulting from different environmental conditions and were not taxonomically distinct and therefore not 'varieties' as described in many texts.

Taxonomy References

Howson & Picton, 1997, Hayward & Ryland, 1995b, Manuel, 1988, Bucklin, 1985,

General Biology

Growth form

Radial
Globose

Feeding method

Passive suspension feeder

Mobility/Movement

Temporary attachment

Environmental position

Epilithic
Epifaunal

Typical food types

Zooplankton but also larger prey. (See additional information.)

Habit

Erect

Bioturbator

Not relevant

Flexibility

High (>45 degrees)

Fragility

Intermediate

Size

Medium-large(21-50cm)

Height

Up to 30 cm

Growth Rate

9 cm/month

Adult dispersal potential

<10m

Dependency

Independent

Sociability

Gregarious

Toxic/Poisonous?

General Biology Additional Information

Growth rate

Bucklin (1987a) observed that Metridium senile grew rapidly in laboratory culture when fed daily reaching a mean pedal diameter of 45 cm after 5 months.

Feeding

Anthony (1997) noted that small anemones had the highest feeding efficiency at moderate to high flow regimes (which might help to account for the prevalence of small individuals at wave-exposed locations).
Robbins & Schick (1980) found that current strength was the principal cause of expansion in Metridium senile rather than food availability. The greatest percentage of the anemones were expanded when the tide was running than at slack water.
Examination of waste pellets of Metridium senile on wharf pilings in Monterey Bay, California (Purcell, 1976) revealed a diet of copepods, polychaete larvae, bivalve and gastropod veligers, copepod naupliii, and barnacle nauplii and cyprids.
Sebens (1984) demonstrated that barnacle cyprids, ascidian larvae and gammarid amphipods were the preferred food of Metridium senile over invertebrate eggs, foramaniferans, calanoid and harpacticoid copepods and ostracods.

Predation on Metridium senile

Metridium senile is subject to predation from both small and large consumers. The life stages of the sea spider Pycnogonum littorale found feeding on the anemone were reported by Wilhelm et al. (1997). The sea slug Aeolidia papillosa also feeds on Metridium senile (see, for instance, Reidy, 1996; Sebens, 1985). Sebens (1985) reported heavy mortality every winter in the Gulf of Maine, USA from Aeolidia papillosa. However, infestations may be sporadic. Gorzula & Cameron (1976) reported a population boom of Aeolidia papillosa at Millport, Firth of Clyde during February 1974 and that it was the third recorded that century. Effects on the Metridium senile population were considerable although the slugs vanished after four weeks. Epitonid snails (wentletraps) feed on anemones and Perron (1978) observed that Metridium senile was the preferred prey of Epitonium greenlandicum in the Bay of Fundy. Whether north-east Atlantic wentletraps feed on Metridium senile is uncertain although Graham (1988) notes that Epitonium clathrus feeds on Anemonia sulcata. Larger species that eat whole anemones include the black bream Spondyliosoma cantharus (Mattacola, 1976) and, in Newfoundland, the winter flounder Pseudopleuronectes americanus (Keats, 1990).

Biology References

Anthony, 1997, Reidy, 1996, Wilhelm et al., 1997, Keats, 1990, Bucklin, 1987a, Mattacola, 1976, Gorzula & Cameron, 1976, Perron, 1978, Graham, 1988,

Distribution and Habitat

Distribution in Britain & Ireland

All British and Irish coasts.

Global distribution

See additional information below.

Biogeographic range

Not researched

Depth range

Lower shore to considerable depths.

Migratory

Non-migratory / Resident

Distribution Additional Information

The species occurs from Biscay to Scandinavia in the northeast Atlantic. It is unknown from the western basin of the Mediterranean but recorded from the Adriatic (where it is believed to have been introduced) (Manual 1988). The same species occurs on the west and east coasts of North America. It has recently (Griffiths et al., 1996) been reported from Table Bay Harbour in South Africa where it was probably introduced from Europe. Both dianthus and pallidum forms may occur in estuaries and pallidum in brackish creeks. Braber & Borghouts (1977) recorded Metridium senile from salinities as low as 10ppt Chlorinity (about 19psu) in the Delta Region of the Netherlands.

Substratum preferences

Bedrock
Large to very large boulders
Biogenic reef
Artificial (e.g. metal/wood/concrete)
Caves
Overhangs

Physiographic preferences

Offshore seabed
Strait / sound
Ria / Voe

Biological zone

Sublittoral Fringe
Upper Infralittoral
Lower Infralittoral
Upper Circalittoral
Lower Circalittoral

Wave exposure

Extremely Exposed
Very Exposed
Exposed
Moderately Exposed
Sheltered
Very Sheltered
Extremely Sheltered

Tidal stream strength/Water flow

Very Strong (>6 kn)
Strong (3-6 kn)
Moderately Strong (1-3 kn)

Salinity

Full (30-40 psu)

Habitat Preferences Additional Information

Distribution References

Hayward & Ryland, 1995b, Manuel, 1988, Griffiths et al., 1996, Braber & Borghouts, 1977,

Reproduction/Life History

Reproductive type

Fission
Gonochoristic

Developmental mechanism

Lecithotrophic

Reproductive Season

August to September

Reproductive Location

Water column

Reproductive frequency

Insufficient information

Regeneration potential

Life span

11-20 years

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	1-6 months

Reproduction Preferences Additional Information

The Plymouth Marine Fauna (Marine Biological Association, 1957) reports that ova and sperm are produced in August and September at Plymouth. Bull (1939b) records that ova and sperm are given off at intervals throughout the year in north-east England. An account of reproductive cycles in Californian Metridium senile, where spawning occurred in September and October, is given in Bucklin (1982). Sebens (1985) suggests that the larva is lecithotrophic but has a 'pre-metamorphosis' period of months, a dispersal potential of >10,000m and a colonization rate of 5-10 years. Metridium senile colonizes areas aggressively. In studies of succession in rock wall communities in the Gulf of Maine, USA, Sebens (1985), the anemone was a late colonizer but grew over earlier colonizers and used specialized 'catch-tentacles' to damage other anemones and soft corals. The presence of such 'catch-tentacles' is also reported for Metridium senile in Britain (Williamson, 1975).
Growth is rapid. Bucklin (1985), working in Britain, found that for Metridium senile f. dianthus fragments and for Metridium senile f. pallidum newly settled individuals, a growth rate of up to 0.6 mm and 0.8 mm in pedal diameter per day occurred respectively. Bucklin (1987a) found that, for Metridium senile from California, individuals showed rapid growth to large sizes when fed at frequent intervals. Mean size grew steadily during the first eight months then levelled off. An increase from 5 cm² pedal disk area to 45 cm² occurred within 12 months. No information on longevity has been found although it would be expected that individuals are long-lived (10 years +).

Reproduction References

MBA, 1957, Bull, 1939b, Bucklin, 1982, Williams, 1975, Bucklin, 1985, Bucklin, 1987b,