NOUN
- soft unsegmented marine worms that have a threadlike proboscis and the ability to stretch and contract
How To Use nemertean In A Sentence
- Consequently, his conclusion that platyhelminths, nemerteans, and rotifers ‘appear to have never had’ a prototroch is not supported by his analysis.
- Such an association of cells and mechanism of precursor translocation have not been reported from nemerteans previously.
- Frontal glands have been cited in the classical literature as probable homologues of Platyhelminthes and nemerteans.
- 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.
- In contrast to platyhelminths, nemerteans possess a circulatory system, comprised of fluid-filled, cell-lined channels situated between the gut and body-wall musculature.
- 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.
- The organization of the body compartment between the epidermis and gut in nemerteans and flatworms also does not reveal a uniquely similar pattern.
- Most nemerteans found in San Francisco Bay are very small and not easily identifiable.
- 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.
- The phylogenetic position of nemerteans remains controversial.