Echinus esculentus

Researched ByDr Harvey Tyler-Walters and Lizzie TylerData Supplied ByMarLIN and University of Sheffield
Refereed byThis information is not refereed.
Taxonomy
Scientific nameEchinus esculentusCommon nameEdible sea urchin
MCS CodeZB198Recent SynonymsNone
PhylumEchinodermataSubphylumEchinozoa
SuperclassClassEchinoidea
SubclassOrderEchinoida
SuborderFamilyEchinidae
GenusEchinusSpeciesesculentus
Subspecies  
Additional InformationThe genus Echinus is derived from the Greek 'echinos' meaning 'a hedgehog'. An omnivorous grazer feeding on seaweeds (e.g. Laminaria spp. sporelings), Bryozoa, barnacles and other encrusting invertebrates. Size range varies depending on age and locality, e.g. c. 4 cm at 1 year, 4-7 cm at 2 years, 7 -9 cm at 3 years and 9-11 cm at 4 years. This species may hybridize with Echinus acutus if sympatric.
Taxonomy References Hayward & Ryland, 1995b, Howson & Picton, 1997, Mortensen, 1927, Fish & Fish, 1996, Hyman, 1955, Nichols, 1969
General Biology
Growth formGloboseFeeding methodGrazer (grains/particles), Grazer (fronds/blades), Grazer (surface/substratum)
Mobility/MovementCrawlerEnvironmental positionEpifaunal
Typical food typesRecorded feeding on; worms, barnacles (e.g. Balanus spp.), hydroids, tunicates, bryozoans (e.g. Membranipora spp.), macroalgae (e.g. Laminaria spp.), bottom material and detritus (reviewed by Lawrence 1975).HabitFree living
BioturbatorNot relevantFlexibilityNone (< 10 degrees)
FragilityFragileSizeMedium(11-20 cm)
HeightGrowth RateSee additional information
Adult dispersal potential1km-10kmDependencyIndependent
SociabilityGregarious
Toxic/Poisonous?No
Additional InformationGrowth rates are variable depending on time of larval settlement, food availability, water temperature and age. Growth rates vary with locality although there is evidence to suggest that largest specimens are found in the south west (Nichols 1979). Growth rates based on growth lines in skeletal plates are probably underestimates (Gage 1992a & b). In the UK population growth is continuous in the first year after metamorphosis and considerably faster than adults in their 2nd year. In adults maximal growth occurs in a few months in spring and early summer but mature adults are slow growing. Comely & Ansell (1988) recorded 28 invertebrate species associated with Echinus esculentus from the west cost of Scotland near Oban. These included the parasites Echinomermella grayi and Euonyx chelatus mentioned above and in additional; 4 species of commensal polychaetes, a copepod and 10 amphipod species. The polychaete Adyte assimilis and the copepod Pseudoanthessius liber were regular commensals amongst the spines. Hyman (1955) states that Echinus esculentus is often infested with parasitic copepods e.g. Asterocheres echinola.
Biology References Hayward & Ryland, 1995b, Mortensen, 1927, Fish & Fish, 1996, Lawrence, 1975, MacBride, 1903, Kozloff & Westervelt, 1990, Comely & Ansell, 1988, Hyman, 1955, Gage, 1992(a), Gage, 1992(b), Nichols, 1979, Nichols, 1969, Emson & Moore, 1998, MacBride, 1914, Nichols, 1984, Boolootian, 1966, Birkett et al., 1998b, Hayward & Ryland, 1990, Julie Bremner, unpub data, Mortensen, 1927, Rees & Dare, 1993
Distribution and Habitat
Distribution in Britain & IrelandCommon on most coasts of the British Isles but absent from most of east coast of England, the eastern English Channel and some parts of north Wales.
Global distributionAbundant in the N.E. Atlantic from Iceland, north to Finmark, Norway and south to Portugal. Absent from the Mediterranean.
Biogeographic rangeNot researchedDepth range0 - 1200 m
MigratoryNon-migratory / Resident
Distribution Additional InformationNo text entered
Substratum preferencesBedrock, Large to very large boulders, Small boulders, Artificial (e.g. metal/wood/concrete), Rockpools, Under boulders, Caves, Crevices / fissures, OverhangsPhysiographic preferencesOpen coast, Strait / sound, Sealoch, Ria / Voe, Enclosed coast / Embayment
Biological zoneSublittoral Fringe, Upper Infralittoral, Lower Infralittoral, Upper Circalittoral, Lower CircalittoralWave exposureExposed, Moderately Exposed, Sheltered
Tidal stream strength/Water flowModerately Strong (1-3 kn)SalinityFull (30-40 psu)
Habitat Additional Information
AMBI Group (Borja et al., 2000)I 
Distribution References Hayward & Ryland, 1995b, Mortensen, 1927, Fish & Fish, 1996, Hyman, 1955, Nichols, 1979, Nichols, 1969, Nichols, 1984, JNCC, 1999, Picton & Costello, 1998, NBN, 2002, Hayward & Ryland, 1990, Julie Bremner, unpub data
Reproduction/Life History
Reproductive typeGonochoristic Developmental mechanismPlanktotrophic
Reproductive SeasonSpringReproductive LocationWater column
Reproductive frequencyAnnual episodic Regeneration potentialNo
Life span6-10 yearsAge at reproductive maturity1-2 years
Generation time1-2 yearsFecundity20000000
Egg/propagule sizeFertilization typeExternal
Larvae/Juveniles
Larval/Juvenile dispersal potential>10kmLarval settlement period
Duration of larval stage1-2 months  
Additional Information
  • Nichols (1979) estimates the maximum life span to be between 8-10 years, whereas Gage (1992a) reports a specimen (based on growth bands) of at least 16 years of age.
  • The number of eggs produced will vary with location and nutritive state of the adult but it is likely to be high. MacBride (1903) states that a well-grown female contains about 20 million eggs.
  • Maximum spawning occurs in spring although individuals may spawn over a protracted period. Gonad weight is maximal in February / March in English Channel (Comely & Ansell 1989) but decreases during spawning in spring and then increases again through summer and winter until the next spawning; there is no resting phase. Spawning occurs just before the seasonal rise in temperature in temperate zones but is probably not triggered by rising temperature (Bishop 1985). Spawning may coincide with spring phytoplankton bloom although there is no evidence to substantiate this suggestion.
  • Comely & Ansell (1989) demonstrated differences in reproductive condition between sites and habitats. Emson & Moore (1998) noted that gonad size varied with diet in the Isle of Cumbrae, Scotland; specimens feeding on barnacles had a higher gonad index than those feeding within the kelp forest.
  • Planktonic development is complex and takes between 45 -60 days in captivity (MacBride 1914). Development includes a blastula, gastrula and a characteristic, four armed echinopluteus stage that forms an important component of the zooplankton. The development of Echinus esculentus is described in detail by MacBride (1903, 1914). Photographs of the echinopluteus and fully formed juveniles are given by Todd et al. (1996).
  • Recruitment is sporadic or variable depending on locality, e.g. Millport populations showed annual recruitment, whereas few recruits were found in Plymouth populations during Nichols studies between 1980-1981 (Nichols 1984). Bishop & Earll (1984) suggested that the population of Echinus esculentus at St Abbs had a high density and recruited regularly whereas the Skomer population was sparse, ageing and had probably not successfully recruited larvae in the previous 6 years.
  • Settlement is thought to occur in autumn and winter (Comely & Ansell, 1988). Newly settled juveniles have an ambital diameter of 0.68 - 0.95mm (Nichols 1984).
  • Comely & Ansell (1988) noted that the largest number of Echinus esculentus occurred below the kelp forest. Similarly, Lang & Mann (1978) noted that young Strongylocentrotus droebachiensis recruited in urchin barrens, suggesting that urchin recruitment is improved in the absence of kelp, presumably due to differences in microclimate, the absence of suspension feeders and other predators associated with kelp beds.
Reproduction References Lawrence, 1975, MacBride, 1903, Hyman, 1955, Gage, 1992(a), Gage, 1992(b), Nichols, 1979, Nichols, 1969, Emson & Moore, 1998, MacBride, 1914, Nichols, 1984, Lang & Mann, 1978, Bishop, 1985, Boolootian, 1966, Bishop & Earll, 1984, Todd et al., 1996, Julie Bremner, unpub data, Rees & Dare, 1993