BIOTIC

BIOTIC Species Information for Arenicola marina
All Taxonomy Biology Distribution Reproduction

Researched by	Dr Harvey Tyler-Walters	Data supplied by	MarLIN
Refereed by	Dr Matt Bentley
General Biology
Growth form	Vermiform segmented Vermiform annulated Cylindrical	Feeding method	Sub-surface deposit feeder
Mobility/Movement	Burrower	Environmental position	Infaunal
Typical food types	Micro-organisms (bacteria), benthic diatoms, meiofauna, and detritus.	Habit	Burrow dwelling
Bioturbator	Insufficient information	Flexibility	High (>45 degrees)
Fragility	Fragile	Size	Medium(11-20 cm)
Height	Not relevant	Growth Rate	Insufficient information
Adult dispersal potential	100-1000m	Dependency	Independent
Sociability	Solitary
Toxic/Poisonous?	No
General Biology Additional Information	The anatomy of Arenicola marina was described in detail by Ashworth (1904). Arenicola marina burrows into sediment using its proboscis and muscular contractions of the first few segments. It forms a J-shaped burrow (see image) with a vertical shaft and horizontal limb in which the worm lies head first. Arenicola marina ingests sediment at head end of the burrow forming a feeding column and characteristic funnel or 'blow hole' on the surface (Wells, 1945; Zebe & Schiedek, 1996). Therefore, it feeds on material obtained from the sediment surface. The shape and different feeding characteristics of the funnel were discussed and photographed by Rijken (1979). Arenicola marina ingests small particles (<2mm) which stick to the proboscis papillae while larger particles are rejected and accumulate in the vicinity of the burrow, often resulting in a characteristic layer of shell material below the burrow found in sediments populated by this species (Zebe & Schiedek, 1996; Riisgård & Banta, 1998). Arenicola marina feeds on micro-organisms (bacteria), meiofauna and benthic diatoms in the sediment and is also capable of absorbing dissolved organic matter (DOM) such as fatty acids through the body wall (Zebe & Schiedek, 1996). Feeding, defaecation and burrow irrigation is cyclic. Each cycle takes about 42 minutes in large worms but 15 min in smaller worms, depending on individual. Each cycle consists of defaecation (worm mainly in the tail-shaft), followed by rapid irrigation and a longer period of feeding, after which the worm defaecates again and the cycle repeats (Wells, 1949; Russell-Hunter, 1979; Riisgård & Banta, 1998) The burrow is irrigated (and therefore aerated) by intermittent cycles of peristaltic contractions of the body from the tail to the head end. Therefore, fresh water is taken in at the tail end and leaves by percolation through the feeding column. Arenicola marina can extract 32 -40% of the oxygen in burrow water, mainly through the gills but partly through the body surface. The blood has a high oxygen carrying capacity due to the presence of high concentrations of extracellular haemoglobin. At low tide, when supply of fresh water is not available, movement is reduced to a minimum. Arenicola marina is capable of anaerobic metabolism in hypoxic conditions (see Zeber & Schiedek, 1996 for review). Tail-nipping by flatfish, Nereis virens, and Hediste diversicolor results in loss of a few tail segments, which are not replaced, tail length being made up by increasing the length of the remaining segments. The tail is important for the storage of faeces. Storage of faeces minimises defaecation at the surface, and therefore resultant risk of predation. Tail-nipping results in decreased overall growth (de Vlas, 1979). Newell (1948) noted that the average length of adult Arenicola marina decreased over-winter then rapidly increased in spring to reach a maximum in September. Ashworth (1904) recorded the presence of Distomid cercariae and Coccidia in Arenicola marina from the Lancashire coast.
Biology References	Fish & Fish, 1996, Hayward & Ryland, 1995b, Hayward et al., 1996, Cadman & Nelson-Smith, 1993, Everson, 2000, Ashworth, 1904, Zebe & Schiedek, 1996, Hayward, 1994, Wells, 1945, Beukema & de Vlas, 1979, Vlas de, 1979, Rijken, 1979, Wilde & Berghuis, 1979, Wells, 1949, Russell-Hunter, 1979., Farke & Berghuis, 1979, Dillon & Howie, 1997, Riisgård & Banta, 1998, Clay, 1967,