SGER: Phylogency, Reproductive Mode, and Parasitism in Antarctic Cidaroid Sea Urchins

University Of California-Santa Cruz, Santa Cruz CA

Investigators

Abstract

The origin of Antarctic biota remains uncertain. Shallow-water, circum-antarctic habitats have been isolated from the rest of the world since Antarctica separated from Australia forty million years. With the separation of Antarctica from South American 25 million years ago, and the inception of the Antarctic Circumpolar Current and the Polar Frontal zone, the isolation of the Antarctic biota from the rest of the world's oceans was nearly complete. The exception is the deep sea, which is replenished by cold, sinking Antarctic bottomwater. Many Antarctic species are endemic with apparent affinities to species in the deep sea. A major question about the Antarctic biota is whether deep-sea organisms invaded and radiated into the Antarctic benthos after it was isolated and cooled or the Antarctic biota is a refugium and/or source of deep-sea organisms and Antarctic species invaded the deep sea. This research will focus on cidaroid sea urchins, as part of an international Antarctic deep-sea biodiversity program to be conducted on the German Antarctic program's research vessel Polarstern. The cruise will be conducted in the Scotia and Weddell Seas. Material collected from the Antarctic shelf to the floor of the adjacent deep sea will form the basis for a phylogenetic analysis to help resolve origin of this group of organisms. Studies will also include a focus on larval development, which is unknown in some species. Finally, an examination of a fungus-like parasite which occurs on the spines of some species of Antarctic cidaroids, will be conducted in order to place this parasite into a recognized higher taxonomic category, and to open the possibility for understanding how it influences echinoid development. This project will provide new information on a understudied part of the world's ocean and will contribute to the study of the world's biodiversity.