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.

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,