A new nemertean species: what are the useful characters for ribbon worm descriptions?

Abstract

In recent years the Norwegian Taxonomy Initiative started thorough investigations of poorly known organism groups. In this context, several marine inventories have rendered a number of marine invertebrate species new to science. Within the phylum Nemertea (ribbon worms) a characteristic hoplonemertean was encountered on two different occasions. We describe the new species Amphiporus rectangulus sp. nov. with a combination of histology and DNA data (COI). For the morphological description we use a previously proposed character matrix and, in a context given by the results, also provide a brief discussion on benefits and drawbacks with both methods. We argue that for small animals with soft bodies external characters can be more informative than hitherto expected.