BIOTIC Species Information for Ascidiella scabra
Researched byDr Keith Hiscock Data supplied byMarLIN
Refereed byThis information is not refereed.
Scientific nameAscidiella scabra Common nameA sea squirt
MCS CodeZD85 Recent SynonymsNone

PhylumChordata SubphylumTunicata
Superclass ClassAscidiacea
Subclass OrderEnterogona
SuborderPhlebobranchiata FamilyAscidiidae
GenusAscidiella Speciesscabra

Additional InformationSpecimens as large as 7.5 cm have been sampled from the Dogger Bank. Almost colourless examples can be found.
Taxonomy References Lindsay & Thompson, 1930, Berril, 1950, Millar, 1970,
General Biology
Growth formBullate / Saccate
Feeding methodActive suspension feeder
Mobility/MovementPermanent attachment
Environmental positionEpibenthic
Typical food typesSuspended particles including phytoplankton HabitAttached
BioturbatorNot relevant FlexibilityHigh (>45 degrees)
FragilityFragile SizeSmall-medium(3-10cm)
HeightUp to 4 cm. Growth Rate
Adult dispersal potentialNone DependencyIndependent
General Biology Additional InformationAscidiella scabra is usually about 2-3 cm in length although specimens from the Dogger Bank have been recorded at 7.5 cm in length (Lindsay & Thompson, 1930)
Biology References Lindsay & Thompson, 1930,
Distribution and Habitat
Distribution in Britain & IrelandPresent all around Britain and Ireland.
Global distributionPresent from the Faeroe Islands and Trondheimfjord in the north, occurring in the Kattegat and extending into the Mediterranean.
Biogeographic rangeNot researched Depth range+2 - 300 m
MigratoryNon-migratory / Resident   
Distribution Additional Information

Substratum preferencesArtificial (e.g. metal/wood/concrete)
Large to very large boulders
Small boulders
Under boulders
Biogenic reef
Physiographic preferencesOpen coast
Offshore seabed
Strait / sound
Ria / Voe
Enclosed coast / Embayment
Biological zoneSublittoral Fringe
Upper Infralittoral
Lower Infralittoral
Upper Circalittoral
Lower Circalittoral
Wave exposureModerately Exposed
Very Sheltered
Extremely Sheltered
Tidal stream strength/Water flowStrong (3-6 kn)
Moderately Strong (1-3 kn)
Weak (<1 kn)
SalinityFull (30-40 psu)
Variable (18-40 psu)
Habitat Preferences Additional Information
Distribution References Lindsay & Thompson, 1930, Millar, 1970, NBN, 2002,
Reproduction/Life History
Reproductive type Developmental mechanism
Reproductive SeasonInsufficient information Reproductive Location
Reproductive frequencyAnnual protracted Regeneration potential No
Life span3-5 years Age at reproductive maturity<1 year
Generation time<1 year FecundityInsufficient information
Egg/propagule size Fertilization type
Larval/Juvenile dispersal potential1km-10km Larval settlement period
Duration of larval stage2-10 days   
Reproduction Preferences Additional InformationLindsay & Thompson (1930) noted the great fecundity of Ascidiella scabra and that eggs were produced (in the laboratory) from March onwards. Berrill (1950) notes that the species is oviparous, that the eggs are small (0.16 mm diameter) and sink in still water. Tadpole larvae emerge from eggs.
Reproduction References Lindsay & Thompson, 1930, Berril, 1950,
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