Cirratulus cirratus

Researched By	Lizzie Tyler	Data Supplied By	University of Sheffield
Refereed by	This information is not refereed.
Taxonomy
Scientific name	Cirratulus cirratus	Common name	A bristleworm
MCS Code	P836	Recent Synonyms	None
Phylum	Annelida	Subphylum
Superclass		Class	Polychaeta
Subclass		Order	Spionida
Suborder		Family	Cirratulidae
Genus	Cirratulus	Species	cirratus
Subspecies
Additional Information	Cirratulus cirratus is usually found in aggregations of up to 200 individuals. During the breeding season their colour changes, the females become bright yellow and the males white.
Taxonomy References	Hayward & Ryland, 1995b, Fauchald, 1977, Hayward et al., 1996, Fish & Fish, 1996, Howson & Picton, 1997
General Biology
Growth form	Cylindrical, Vermiform segmented	Feeding method	Surface deposit feeder, Sub-surface deposit feeder
Mobility/Movement	Burrower	Environmental position	Infaunal
Typical food types	Diatoms and algal detritus.	Habit	Burrow dwelling
Bioturbator	Diffusive mixing	Flexibility	High (>45 degrees)
Fragility	Fragile	Size	Medium(11-20 cm)
Height	Not relevant	Growth Rate	<2cm / reproductive episode (every 1-2 yrs)
Adult dispersal potential	None	Dependency	Independent
Sociability	Solitary
Toxic/Poisonous?	No
Additional Information	Little information on the general biology or life history characteristics of this species was found. Cirratulus cirratus is regarded as a generally tolerant species and can be found in moderate densities in areas of high environmental disturbance (e.g. 120 per m² 500 m away from an oil platform) (Levell et al., 1989). Once larvae and juveniles settle, they remain in their burrow and adults do not move. It can grow up to 2 cm between reproductive episodes, which occur every 1-2 years (Olive, 1970).
Biology References	Garwood, 1982, Levell, et al., 1989, Olive, 1970, Penry & Jumars, 1990, Gibbs, 1971, Hayward & Ryland, 1995b
Distribution and Habitat
Distribution in Britain & Ireland	Found in suitable habitats all round the coast of Britain and Ireland.
Global distribution	Most north west European coasts and also in the south Atlantic.
Biogeographic range	Not researched	Depth range
Migratory	Non-migratory / Resident
Distribution Additional Information	In Northumberland it is the dominant crevice organism on rocky shores between low and high water neaps (Olive, 1970). Cirratulus cirratus has been described as an opportunistic deposit feeder that is characteristic of areas of organic enrichment (Penry & Jumars, 1990). Cirratulus cirratus is mostly intertidal but is sometimes found subtidally (up to 50 m depth off the Devon coast) (Garwood, 1982; Olive, 1970).
Substratum preferences	Under boulders, Muddy gravel, Mud	Physiographic preferences	Open coast, Offshore seabed, Strait / sound
Biological zone	Upper Eulittoral, Mid Eulittoral, Lower Eulittoral, Sublittoral Fringe, Lower Infralittoral, Upper Circalittoral, Lower Circalittoral	Wave exposure	Sheltered, Very Sheltered, Extremely Sheltered
Tidal stream strength/Water flow	Weak (<1 kn)	Salinity	Reduced (18-30 psu), Variable (18-40 psu), Full (30-40 psu)
Habitat Additional Information	None entered
AMBI Group (Borja et al., 2000)	IV
Distribution References	JNCC, 1999, NBN, 2002, Hayward & Ryland, 1995b, Fauchald, 1977, Hayward et al., 1996, Fish & Fish, 1996, Hayward & Ryland, 1995b
Reproduction/Life History
Reproductive type	Gonochoristic	Developmental mechanism	Lecithotrophic
Reproductive Season	Asynchronous reproduction	Reproductive Location	Sediment surface
Reproductive frequency	Biannual episodic	Regeneration potential	No
Life span	6-10 years	Age at reproductive maturity	1-2 years
Generation time	1-2 years	Fecundity
Egg/propagule size	150 µm diameter	Fertilization type	Insufficient information
Larvae/Juveniles Larval/Juvenile dispersal potential Insufficient information Larval settlement period Insufficient information Duration of larval stage
Additional Information	Reproduction in Cirratulus cirratus is asynchronous i.e. it is not entrained to any of the seasons and members of the population are at different stages of reproductive development at any one time (Garwood, 1982; Gibbs, 1971). Oocytes are 150 µm in diameter and once fertilized are deposited in a jelly mass on the surface of rocks (Petersen, 1999). The eggs hatch as a ciliated post-trochophore after 6 days. The larvae are entirely benthic for the duration of their development, living off yolk for around 24 days after hatching and then commence adult style deposit feeding (Olive, 1970). Females can spawn 2-3 times in their lifetime and it takes 1-2 years after each spawning to mature a new clutch of oocytes (Olive, 1970). There are separate sexes, the males are white, females are lemon-yellow due to the colour of coelomic oocytes (Gibbs, 1971). Sex ratios vary and have been recorded as 1:1 (Olive, 1970) 1:1.7 and 1:2.8 (Gibbs, 1971). Asexual reproduction by epitoky (clones growing from the posterior end of the worm) may occur in Cirratulus cirratus. However, the taxonomic status of Cirratulus is in constant review and epitokes may be formed by another species that has been erroneously identified as Cirratulus cirratus (Petersen, 1999).
Reproduction References	Garwood, 1982, Olive, 1970, Gibbs, 1971, Petersen, 1999, George, 1968, George, 1971