Image from Identification and Ecology of Australian Freshwater Invertebrates.

The Phylum Nemertea (1150 spp.) is predominantly marine, but ca. 25 species are known from fresh waters. Three species in two genera are known from North America (Sundberg & Gibson, 2008).

The nemerteans are known as the “proboscis worms” for their eversible proboscis, which they use to capture prey and support their carnivorous life-style. They possess a complete one-way gut, allowing for regional specialization of the alimentary canal and more efficient digestion than the blind sac seen in Platyhelminthes. Nemerteans have a closed-but-low-pressure circulatory system. The central nervous system is of the protostome type with two ventral nerve cords joined by lateral connectives. Freshwater nemerteans are generally in the mm to cm size range.

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Bibliography

• Zhang, Z.-Q. 2011. Animal biodiversity: An introduction to higher-level classification and taxonomic richness. Zootaxa 3148: 7-12. [Available online]
• Kolasa, J. & S. Tyler. 2010. Flatworms: Turbellarians and Nemerteans. [in] J.H. Thorp & A.P. Covich (eds.). Ecology and Classification of North American Freshwater Invertebrates, 3rd edition: 143-161.
• Sundberg, P. & R. Gibson. 2008. Global diversity of nemerteans (Nemertea) in freshwater. Hydrobiologia 595: 61-66. [Available online]
• Watermolen, D.J. 2005. Aquatic and terrestrial flatworm (Platyhelminthes, Turbellaria) and ribbon worm (Nemertea) records from Wisconsin. Research/Management Findings, Wisconsin DNR (55). 8 pp.
• Brusca, R.C. & G.J. Brusca. 2003. Invertebrates, 2nd edition. Sinauer Associates, Inc., Sunderland, Massachusetts. 936 pp.
• Smith, D.G. 2001. Nemertea (Proboscis worms). Pennak's Freshwater Invertebrates of the United States, 4th edition: 109-115.
• Gibson, R. & J. Moore. 1976. Freshwater nemerteans. Zoological Journal of the Linnean Society 58: 177-218. [Available online]
• Browning, R.F. 1972. A record of the freshwater nemertean, Prostoma rubrum, in Wisconsin. Transactions of the Wisconsin Academy of Science, Arts & Letters 60: 179-180. [Available online]
• Coe, W.R. 1959. Nemertea. [in] W.T. Edmondson (ed.). Ward & Whipple Fresh-Water Biology, 2nd edition: 366-367.

Student Essays

• "Nemertea and their feeding processes through use of the proboscis" by Matthew Feltes (BIOL/WATR 361, Spring 2015 )

Web Pages

• Animal Diversity Web
• Integrated Taxonomic Information System
• Introduction to the Nemertini. Tied up in knots...
• Nemertea: Portal to the Nemertean Universe
• Systema Naturae 2000
• Tree of Life
• WikiSpecies
• Wikipedia
• World Register of Marine Species