BIOTIC

BIOTIC Species Information for Brissopsis lyrifera
All Taxonomy Biology Distribution Reproduction

Researched by	Lizzie Tyler	Data supplied by	University of Sheffield
Refereed by	This information is not refereed.
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
General Biology 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,