Echinocardium cordatum

Researched By	Lizzie Tyler	Data Supplied By	University of Sheffield
Refereed by	This information is not refereed.
Taxonomy
Scientific name	Echinocardium cordatum	Common name	Sea-potato
MCS Code	ZB223	Recent Synonyms	None
Phylum	Echinodermata	Subphylum	Echinozoa
Superclass		Class	Echinoidea
Subclass		Order	Spatangoida
Suborder		Family	Loveniidae
Genus	Echinocardium	Species	cordatum
Subspecies
Additional Information	The common name of this species refers to the brittle, brownish test, which is often found washed up on sheltered sandy shores.
Taxonomy References	Fish & Fish, 1996, Hayward et al., 1996, Mortensen, 1927
General Biology
Growth form	Globose	Feeding method	Surface deposit feeder, Sub-surface deposit feeder
Mobility/Movement	Burrower	Environmental position	Infaunal
Typical food types	Detritus	Habit	Burrow dwelling
Bioturbator		Flexibility	None (< 10 degrees)
Fragility	Fragile	Size	Small-medium(3-10cm)
Height	Insufficient information	Growth Rate	1-2 cm/year
Adult dispersal potential	1km-10km	Dependency	Independent
Sociability	Gregarious
Toxic/Poisonous?	No
Additional Information	Growth rate: Growth in Echinocardium cordatum is particularly rapid during the first and second years of life. There are also seasonal variations that are characterised by an alternation of slow and rapid growth rates, with rapid growth during spring and summer months (Ridder de et al., 1991). The bivalve Tellimya (=Montacuta) ferruginosa is a commensal of Echinocardium cordatum, and as many as 14 or more of this bivalve have been recorded with a single echinoderm. Adult specimens live freely in the burrow of Echinocardium cordatum, while the young are attached to the spines of the echinoderm by byssus threads (Fish & Fish, 1996). The amphipod crustacean Urothöe marina (Bate) is another common commensal (Hayward & Ryland, 1995).
Biology References	Fish & Fish, 1996, Hayward et al., 1996, Hayward & Ryland, 1995b, Ridder de et al., 1991, Nichols, 1969, Hayward & Ryland, 1990, Julie Bremner, unpub data
Distribution and Habitat
Distribution in Britain & Ireland	Echinocardium cordatum is a common infaunal species found on sheltered sandy beaches, on all coasts of Britain and Ireland.
Global distribution	Almost cosmopolitan except for polar seas: Norway to South Africa, Mediterranean, Australasia and Japan.
Biogeographic range	Not researched	Depth range	0 - 230 m
Migratory	Seasonal (reproduction)
Distribution Additional Information	The species has an annual tendency to form aggregations during the breeding season (Buchanan, 1966). There is also a migration of individuals from the subtidal to the intertidal at about 2 years of age.
Substratum preferences	Coarse clean sand, Fine clean sand, Muddy sand, Sandy mud	Physiographic preferences	Open coast, Offshore seabed, Strait / sound, Enclosed coast / Embayment
Biological zone	Lower Eulittoral, Sublittoral Fringe, Upper Infralittoral, Lower Infralittoral, Upper Circalittoral, Lower Circalittoral, Circalittoral Offshore	Wave exposure	Sheltered, Very Sheltered, Extremely Sheltered
Tidal stream strength/Water flow	Insufficient information	Salinity	Reduced (18-30 psu), Full (30-40 psu)
Habitat Additional Information
AMBI Group (Borja et al., 2000)	I
Distribution References	Fish & Fish, 1996, Hayward & Ryland, 1995b, Buchanan, 1966, Higgins, 1974, Hayward & Ryland, 1990, Julie Bremner, unpub data
Reproduction/Life History
Reproductive type	Gonochoristic	Developmental mechanism	Planktotrophic
Reproductive Season	Spring and summer	Reproductive Location	Water column
Reproductive frequency	Annual episodic	Regeneration potential	No
Life span	11-20 years	Age at reproductive maturity
Generation time	Insufficient information	Fecundity	1000000
Egg/propagule size		Fertilization type	External
Larvae/Juveniles Larval/Juvenile dispersal potential Insufficient information Larval settlement period Insufficient information Duration of larval stage
Additional Information	Life span: Observation of populations of Echinocardium cordatum over a period of 7 years suggests the species has a life span greater than 10 years (Buchanan, 1966; Hayward et al., 1996). However, in the Mediterranean Guillou (1985) suggests the life span is one or two years. Age at maturity: On the north-east coast of England a littoral population bred for the first time when three years old. In the warmer waters of the west of Scotland breeding has been recorded at the end of the second year (Fish & Fish, 1996). However, it has been observed that subtidal populations appear never to reach sexual maturity (Buchanan, 1967). Recruitment: Often sporadic, with reports of Echinocardium cordatum recruiting in only 3 years over a 10 year period (Buchanan, 1966) although this relates to subtidal populations. Intertidal individuals reproduce more frequently. The sexes are separate and fertilization external, with the development of a pelagic larva (Fish & Fish, 1996). The fact that Echinocardium cordatum is to be found associated with several different bottom communities would indicate that the larvae are not highly selective and discriminatory and it is probable that the degree of discrimination in 'larval choice' becomes diminished with the age of the larvae (Buchanan, 1966). Metamorphosis of larvae takes place within 39 days after fertilization (Kashenko, 1994).
Reproduction References	Fish & Fish, 1996, Hayward et al., 1996, Buchanan, 1966, Buchanan, 1967, Guillou, 1985, Kashenko, 1994, Julie Bremner, unpub data, Rees & Dare, 1993