Botryllus schlosseri

Researched By	Lizzie Tyler	Data Supplied By	University of Sheffield
Refereed by	This information is not refereed.
Taxonomy
Scientific name	Botryllus schlosseri	Common name	Star ascidian
MCS Code	ZD126	Recent Synonyms	None
Phylum	Chordata	Subphylum	Tunicata
Superclass		Class	Ascidiacea
Subclass		Order	Pleurogona
Suborder	Stolidobranchiata	Family	Styelidae
Genus	Botryllus	Species	schlosseri
Subspecies
Additional Information	No text entered
Taxonomy References	Berril, 1950
General Biology
Growth form	Cushion, Crustose soft	Feeding method	Passive suspension feeder, Active suspension feeder
Mobility/Movement	Permanent attachment	Environmental position	Epifaunal, Epilithic
Typical food types	Suspended particulates.	Habit	Attached
Bioturbator	Not relevant	Flexibility	High (>45 degrees)
Fragility	Intermediate	Size	Medium(11-20 cm)
Height		Growth Rate	Insufficient information
Adult dispersal potential	100-1000m	Dependency	Independent
Sociability	Colonial
Toxic/Poisonous?	No
Additional Information	Colonies that encrust algae may completely cover their substratum and appear pendant-like. Provides a source of food for cowries (Trivia spp.).
Biology References	Chadwick-Furman & Weissman, 1995, Berril, 1950
Distribution and Habitat
Distribution in Britain & Ireland	Found all around Britain and Ireland
Global distribution	Present from the Faeroe Islands and west and south Norway to the Mediterranean including the Adriatic and Black Seas. Also present in the western Atlantic from Maine to New Jersey and in Florida.
Biogeographic range	Not researched	Depth range
Migratory	Non-migratory / Resident
Distribution Additional Information	Populations in the western Atlantic may have arrived on shipping and it is likely that, as a fast-growing fouling organism, Botryllus schlosseri may spread readily to other parts of the world.
Substratum preferences	Bedrock, Cobbles, Large to very large boulders, Small boulders	Physiographic preferences	Open coast, Strait / sound, Sealoch, Ria / Voe
Biological zone	Lower Eulittoral, Sublittoral Fringe, Upper Infralittoral, Lower Infralittoral, Upper Circalittoral	Wave exposure	Moderately Exposed, Very Exposed, Exposed, Sheltered, Very Sheltered
Tidal stream strength/Water flow	Very Strong (>6 kn), Strong (3-6 kn), Moderately Strong (1-3 kn), Weak (<1 kn), Very Weak (negligible)	Salinity	Full (30-40 psu), Variable (18-40 psu)
Habitat Additional Information
AMBI Group (Borja et al., 2000)	I
Distribution References	Berril, 1950, Hayward & Ryland, 1990
Reproduction/Life History
Reproductive type	Fission, Permanent hermaphrodite	Developmental mechanism	Lecithotrophic
Reproductive Season	Insufficient information	Reproductive Location	As adult
Reproductive frequency		Regeneration potential	No
Life span	1 year	Age at reproductive maturity	<1 year
Generation time	<1 year	Fecundity	8
Egg/propagule size		Fertilization type	Self-fertile
Larvae/Juveniles Larval/Juvenile dispersal potential 1km-10km Larval settlement period Duration of larval stage <1 day
Additional Information	Up to eight eggs are produced per zooid. After fertilization and development to a tadpole stage, the tadpole is released and is free swimming for up to 36 hours (Berrill 1950; Berrill, 1975).
Reproduction References	Chadwick-Furman & Weissman, 1995, Berril, 1950, Berril, 1975, Eckert, 2003