Research Training Program

Smithsonian Institution
National Museum of Natural History

PROJECT SUMMARY
1997

Sarah C. Hood
University of Nevada, Reno
Reno, Nevada
Jon Norenburg, Ph.D.
Supervising Scientist
Department of Invertebrate Zoology
"It is a dream come true to do research at one of the finest institutions in the world; I am honored to be here."

Relationships and description of a pelagic nemertean worm

ABSTRACT
Commonly known as ribbon worms, nemerteans are nonsegmented worms with an eversible proboscis, unarmed or armed with a style which is used to capture prey. Nemertean worms live in fresh and saltwater in benthic, and pelagic (floating in deep sea currents) environments. There are approximately 1,200 species of nemerteans. One hundred of these comprise a specialized group of pelagic nemerteans living at oceanic depths greater than 1000 m. Unfortunately, approximately half of the pelagic nemerteans have been described from single specimens. In addition, over half of the described pelagic nemertean species lack museum specimens and much of the material that is available is damaged or poorly preserved. There is little known about nemertean phylogenetics and nemertean taxonomy is problematic. These worms have no hard parts to measure or count, and their highly contractile nature makes measuring length difficult and inconsistent. Nemertean taxonomy is based primarily on histolgical serial sections used to reconstruct internal anatomy. This study entailed preparing (sectioning and staining) several well-preserved specimens of an unidentified pelagic nemertean from Hawaii. The slides were examined with a light microscope and a list of characters was constructed. This was used to form a data matrix for the first and preliminary phylogenetic analysis of the pelagic nemerteans. Previous literature was used to determine 28 character states of 8 other taxa from representative pelagic nemerteans. After determining that the specimens represented a new species, a species description was begun. The thorough new species description, large character matrix, and the preliminary phylogeny will contribute to the ongoing research on nemertean phylogenetics and taxonomy.

This research was supported by a grant from the National Science Foundation Research Experiences for Undergraduates program, Award Number DBI-9531331.

Letter of Gratitude