Introduction to nemertean systematics

Abstract

Nemertea is one of the spiralian phyla, consisting of about 1350 species from all over the world. Nemerteans are commonly known as ribbon worms, occurring in a wide variety of marine, freshwater, and terrestrial ecosystems. Although about 100 species of nemerteans have been reported from Japan, recent studies in limited areas involving molecular phylogenetic techniques have uncovered high species diversity in the area, suggesting that there are a significant number of yet-to-be-discovered species in the entire Japanese waters. In this paper, I present a step-by-step introduction to collection, observation, and identification of nemerteans principally for systematic studies. In addition, the present paper briefly reviews recent progress in molecular phylogeny and systematics in the Nemertea.