Meeting Abstract

39.2  Tuesday, Jan. 5  Microeukaryotes and the masters of miniaturization: Diversification in marine sand RUNDELL, Rebecca J.*; LEANDER, Brian S.; University of British Columbia rrundell@interchange.ubc.ca

Marine interstitial environments harbor an extraordinary diversity of coexisting microeukaryotic lineages collectively called “meiofauna.” The extensive geographic distribution and long geological history of interstitial environments suggest that knowledge of meiofaunal diversity is critical for understanding the early evolution of eukaryotic life. Meiofaunal animals such as acoels, gnathostomulids and nemerteans are poorly known, but provide important insights into fundamental patterns of macroevolution, such as the miniaturization of animal body plans, convergence and heterochrony (e.g., paedomorphosis). In this talk, we address the diversification of a few major groups of meiofaunal animals – especially acoels and nemerteans from the eastern Pacific Ocean – using molecular phylogenetic approaches, scanning electron microscopy and light microscopy.