Brissopsis lyrifera

Researched By	Lizzie Tyler	Data Supplied By	University of Sheffield
Refereed by	This information is not refereed.
Taxonomy
Scientific name	Brissopsis lyrifera	Common name	Heart urchin
MCS Code	ZB228	Recent Synonyms	None
Phylum	Echinodermata	Subphylum
Superclass		Class	Echinoidea
Subclass		Order	Spatangoida
Suborder		Family	Brissidae
Genus	Brissopsis	Species	lyrifera
Subspecies
Additional Information
Taxonomy References	Hayward et al., 1996, Hayward & Ryland, 1995b, Howson & Picton, 1997, Picton, 1993, 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	Organic detritus, foraminifers and other small organisms within sediment.	Habit	Free living
Bioturbator		Flexibility	None (< 10 degrees)
Fragility	Fragile	Size	Small-medium(3-10cm)
Height	Insufficient information	Growth Rate	10-15 mm/year
Adult dispersal potential	100-1000m	Dependency	Independent
Sociability	Gregarious
Toxic/Poisonous?	No
Additional Information	Size Ferrand et al. (1988), studied Brissopsis lyrifera in the Gulf of Lions, Mediterranean Sea and found the 'test' length to be unrelated to the sex of the animal. Feeding Brissopsis lyrifera are capable of both deposit feeding and filter feeding although ventilation rates are not high enough to sustain the animal on filter feeding alone (Hollertz, 2002). Brissopsis lyrifera is reported to feed selectively on carbon- and nitrogen-rich particles (Hollertz, 2002). Mucus trapping of fine-organic rich particles and selective collection by the sticky tube feet around the mouth are thought to be the mechanisms underlying this selectivity (Hollertz, 2002). Characteristically, Brissopsis lyrifera is a sub-surface deposit feeder, but Hollertz (1998) observed Brissopsis lyrifera to emerge from the sediment and feed close to the surface in response to the addition of organic matter. When buried in the sediment, Brissopsis lyrifera maintain contact with the surface through a funnel. The funnel is kept clear of sediment by tube feet that also line the funnel with mucus (Hollertz, 2002). In the spatangoids, to which Brissopsis lyrifera belongs, the tube foot pattern typical of the urchins is drastically altered, owing to its highly developed burrowing habit. In addition, the suckered tube-feet are no longer required and they are functionally replaced (in appropriate positions) by burrow-building, sensory or feeding tube-feet. Feeding is achieved by a combination of ciliary action and the action of these sticky, feeding tube-feet. The feeding tube-feet pass material from the substratum into the mouth where organic matter adhering to it are digested and the particular matter voided via the anus (Nichols, 1969). Population densities Brissopsis lyrifera is a gregarious species. Tunberg (1991), found densities of Brissopsis lyrifera to be up to 30 individuals per m² at various locations along the Swedish coast. However, in the North Sea densities of up to 60 individuals per m² have been reported (Ursin, 1960). Mobility and burrowing Despite being a conspicuous and large animal, very little is known about the natural burrowing behaviour of Brissopsis lyrifera, e.g. how much time it spends on the surface and how fast it moves. It is known to burrow about 20 mm below the surface of the substratum and, due to the fact that it moves with a rocking motion through the sediment, is capable of reworking relatively large volumes of sediment (Hollertz & Duchêne, 2001). In laboratory conditions, Hollertz (1998) calculated the locomotion rate of Brissopsis lyrifera to be 11 mm/h, and, using a formula given by Schinner (1993), estimated the turnover rate of sediment by Brissopsis lyrifera to be 8.0 cm² per hour. Further research by Hollertz & Duchêne, (2001) found that Brissopsis lyrifera reworked between 14-22 ml of sediment per hour depending on temperature. Temperature was found to significantly affect burrowing activity that was almost doubled when temperature was raised from 7 to 14 °C. The burrowing activity has a pronounced effect on the surrounding sediment by increases the oxygen concentration in the sediment and thus stimulating the growth of microorganisms and decomposition of organic material (Hollertz & Duchêne, 2001).
Biology References	Hayward & Ryland, 1995b, Widdicombe et al., 2000, Ferrand et al., 1988, Buchanan, 1967, Nichols, 1969, Mortensen, 1927, Tunberg, 1991, Ursin, 1960, Young, 1954, Hollertz, 1998, Schinner, 1993, Hollertz & Duchêne, 2001, Hollertz, 2002, Hayward & Ryland, 1990, Mortensen, 1927
Distribution and Habitat
Distribution in Britain & Ireland	Recorded off the west, north and east coasts of the British Isles, but not off the south coast. Common in deep water.
Global distribution	Brissopsis lyrifera may be found in offshore or inshore stable sediments from Norway and Iceland to South Africa and the Mediterranean. Also present on the east coast of North America but not Greenland.
Biogeographic range	Not researched	Depth range	5 - 500 m
Migratory	Non-migratory / Resident
Distribution Additional Information	Brissopsis lyrifera typically co-occurs with the brittle star, %Amphiura chiajei%, on muddy, soft bottom areas of the North Sea, the Skagerrak and the Kattegat (Hollertz et al., 1998).
Substratum preferences	Mud, Muddy sand	Physiographic preferences	Offshore seabed, Open coast, Sealoch
Biological zone	Lower Circalittoral, Circalittoral Offshore, Bathybenthic (Bathyal)	Wave exposure	Not relevant
Tidal stream strength/Water flow	Weak (<1 kn), Very Weak (negligible)	Salinity	Variable (18-40 psu), Full (30-40 psu)
Habitat Additional Information
AMBI Group (Borja et al., 2000)	I
Distribution References	Hayward et al., 1996, Hayward & Ryland, 1995b, Picton, 1993, Hollertz et al., 1998, Mortensen, 1927, Foster-Smith, 2000, Crothers, 1966, Bruce et al., 1963, Picton & Costello, 1998, JNCC, 1999, Hayward & Ryland, 1990, Mortensen, 1927
Reproduction/Life History
Reproductive type	Gonochoristic	Developmental mechanism	Planktotrophic
Reproductive Season	Summer to Autumn	Reproductive Location	Water column
Reproductive frequency	Semelparous	Regeneration potential	No
Life span	3-5 years	Age at reproductive maturity	3-5 years
Generation time	3-5 years	Fecundity	1000000
Egg/propagule size		Fertilization type	External
Larvae/Juveniles Larval/Juvenile dispersal potential >10km Larval settlement period Insufficient information Duration of larval stage
Additional Information	Reproduction and generation time Echinoids have separate sexes. Fertilization is external and the majority have a free swimming pelagic larva (Fish & Fish, 1996). From observations made along the Northumbrian coast, Buchanan (1967), described Brissopsis lyrifera as a highly productive, short lived but fast growing species. The population he studied showed clear evidence of successful and consecutive annual recruitment. Specimens became sexually mature when 'test' length was >60 mm, they spawned in the summer towards the end of their 4th year and died shortly afterwards. No individuals were observed to survive to breed for a second time. Larval settling time Adults of Brissopsis lyrifera are burrowers, so the larval phase is the main dispersive mechanism of the urchin. Echinoderm larvae undergo a complicated and protracted metamorphosis. For instance, the larvae of other echinoderms, Echinocardium cordatum and Echinus esculentus remain in the plankton for 40 and 46-60 days respectively (Kashenko, 1994; MacBride, 1914). Thus the larvae of Brissopsis lyrifera probably remain in the plankton for a sufficient length of time to be swept away from the location of spawning to new areas, or to restock existing areas (Nichols, 1969).
Reproduction References	Fish & Fish, 1996, Ferrand et al., 1988, Buchanan, 1967, Nichols, 1969, Brattström, 1946, Vasseur & Carlsen, 1949, Kashenko, 1994, MacBride, 1914, Eckert, 2003