Definition of nemertean in English:


(also nemertine)

Pronunciation /nɛməˈtiːən//nɪˈməːtɪən/


  • A member of the small phylum Nemertea; a ribbon worm.

    • ‘Most nemerteans found in San Francisco Bay are very small and not easily identifiable.’
    • ‘Frontal glands have been cited in the classical literature as probable homologues of Platyhelminthes and nemerteans.’
    • ‘The organization of the body compartment between the epidermis and gut in nemerteans and flatworms also does not reveal a uniquely similar pattern.’
    • ‘The phylogenetic position of nemerteans remains controversial.’
    • ‘Such an association of cells and mechanism of precursor translocation have not been reported from nemerteans previously.’


  • Relating to or denoting nemerteans.

    • ‘Some recent investigations of nemertean development have contributed informative characters for phylogenetic analysis, whereas others have provided insight into developmental mechanisms and patterns.’
    • ‘The focal stage for this analysis is the early period of embryo encapsulation, a mode of development that has evolved several times among gastropods, polychaetes, nemerteans and flatworms.’
    • ‘Classical studies revealed that nemertean embryos exhibit spiral cleavage and that the mouth forms at or near the site of the blastopore, but aspects of cell lineage, especially origin of the mesoderm, proved problematic.’
    • ‘Although long considered a character informative for linking nemerteans and platyhelminths, rigorous comparative analyses of protonephridial morphology have revealed no synapomorphies of nemertean and platyhelminth nephridia.’
    • ‘Consequently, his conclusion that platyhelminths, nemerteans, and rotifers ‘appear to have never had’ a prototroch is not supported by his analysis.’