The long-term intent of the World Nemertea Database is to assist in all aspects of nemertean research. The near-term emphasis is providing easy access to current and historical taxonomy of Nemertea, to relevant taxonomic literature and images, and to geographic distribution and trait data of nemertean species.
Species of the phylum Nemertea, or ribbonworms, inhabit all parts of the world's oceans, as well as many freshwater and terrestrial habitats. They are unsegmented worms characterized by a unique and remarkable eversible proboscis used for prey capture and sometimes locomotion. Some are highly specialized predators while others have more eclectic tastes. Diets favor other worms, crustaceans, and mollusks, but can include fish and carrion. In addition to proboscis-borne toxins to subdue prey, nemerteans also have potent integumentary chemical defenses. Some species are strikingly colorful, while others are drab. Most of the known species are free-living but there is a significant number of symbiotic species. Adult worms range from one millimeter to a reported 55 meters long but most are in the range of one centimeter to a few tens of centimeters when relaxed. Their bodies are among the most elastic of metazoans, enabling them to squeeze through very tight spaces, with some capable of extreme elongation. This contributes to nemerteans being poorly known to non-specialists because most live in concealment and are difficult to collect. In addition, until recently, traditional nemertean taxonomy focused strongly on internal anatomy tediously reconstructed from histological study. However, many species actually are common, even abundant, and some clearly are ecologically significant top predators. Current fieldwork of understudied geographic regions accompanied by genetic analyses suggest that at least several times as many species as are now named remain to be discovered and described, and also that most nemertean species are cryptic, i.e., have at least one look-alike. Now genetic data are used extensively to discriminate species and also have revealed important new, sometimes surprising, insights about phylogenetic relationships within Nemertea and of Nemertea among Metazoa. These data also provide new insights into aspects of invertebrate evolution, such as body plans, life histories, toxins, etc.
We acknowledge here with gratitude the contribution of Ray Gibson, the inaugural editor of this database from 2007-2009. The data are based extensively on "Gibson, R (1995). Nemertean genera and species of the world: an annotated checklist of original names and description citations, synonyms, current taxonomic status, habitats and recorded zoogeographic distribution. Journal of Natural History. 29(2): 271–561." See source and entries he provided to the European Register of Marine Species, prior to 2007.