Spirorbis borealis
Spirorbis borealis | |
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Scientific classification ![]() | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Annelida |
Clade: | Pleistoannelida |
Clade: | Sedentaria |
Order: | Sabellida |
Family: | Serpulidae |
Genus: | Spirorbis |
Species: | S. borealis
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Binomial name | |
Spirorbis borealis |
Spirorbis borealis is a sedentary marine
Polychaetes, or marine bristle worms, have elongated bodies divided into many segments. Each
Description
S. borealis secretes a very small, unridged, off-white, calcareous tube. This is about five millimetres in diameter and forms a flat, clockwise spiral coil as seen from above. The worm retreats into its tube when above water but under water can be seen to have green tentacles.[3]
Distribution and habitat
S. borealis is found on either side of the north Atlantic Ocean. This includes the coasts of
Biology
S. borealis is a hermaphrodite. The segments at the front of the abdomen are female while those at the back are male.[1] The male and female gonads mature at much the same time but the sperm is usually released first. Fertilisation is external to the body but inside the tube.[4] The larvae are free swimming member of the plankton for a short time.[5] They then settle out. In a study, where fronds of Fucus serratus already colonised by adults were available for settling, the larvae avoided the most densely populated areas and favoured the concave grooves on either side of the midribs. When prevented from settling out for eight hours, they were much less selective and settled on any Fucus surface regardless of the presence of adults.[6]
References
- ^ a b c d World Register of Marine Species
- ^ Daudin F. M. (1800). Recueil de mémoires et de notes sur l'espèces indites ou peu connues de mollusques, de vers et de zoophytes. Paris pp. 50 + 4 pl:
- ^ a b John Barrett and C M Young, Collins Pocket Guide to the Sea Shore (1958) p.76
- ^ Self- and cross-fertilization in Spirorbis borealis and S. pagenstecheri
- ^ On the larval forms of Spirorbis borealis
- ^ Observations on the Settling Behaviour of Larvae of the Tubeworm Spirorbis borealis, Daudin (Polychaeta)