Janet Moore, University of Cambridge, Cambridge, UK
Ray Gibson, Liverpool John Moores University, Liverpool, UK
Published online: April 2001
DOI: 10.1038/npg.els.0001586
Nemerteans form a phylum of predominantly marine soft-bodied, often elongate, worms with no general body cavity. They are characterized by an eversible proboscis separate from the gut, a gut with separate mouth and anus, and a closed blood system.
Keywords: ribbon-worms; proboscis-worms; Nemertinea; Nemertini; Rhynchocoela
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Figure 1. Schematic vertical longitudinal sections to show the relationships of the gut and proboscis apparatus in Palaeonemertea (a), Heteronemertea (b), Hoplonemertea (Monostilifera) (c) and Bdellonemertea (d). (Modified from Gibson, 1972.)
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Figure 2. The blood system of nemerteans. The basic plan is shown by the palaeonemertean Cephalothrix linearis (a), with various types of elaboration on this found in the heteronemerteans Cerebratulus lacteus (b) and Ramphogordius sanguineus (c), and the hoplonemerteans Amphiporus lactifloreus (d) and Prostoma graecense (e). (Modified from Gibson, 1972.)
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| Further Reading | |
| book Gibson R (1972) Nemerteans. London: Hutchinson University Library. | |
| book Gibson R (1994) Nemerteans. Shrewsbury: Field Studies Council (Synopses of the British Fauna (New Series) No. 24 (Second Edition)). | |
| Moore J and Gibson R (1985) The evolution and comparative physiology of terrestrial and freshwater nemerteans. Biological Reviews 60: 257–312. | |
| book Norenburg JL and Roe P (1998) Fourth International Conference on Nemertean Biology. Dordrecht: Kluwer Academic Publishers. | |
| Turbeville JM, Field KG and Raff RA (1992) Phylogenetic position of phylum Nemertini, inferred from 18S rRNA sequences: molecular data as a test of morphological character homology. Molecular Biology and Evolution 9: 235–249. | |
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