SURFACE ULTRASTRUCTURE OF THE SCYPHOPOLYP, CHRYSAORA QUINQUECIRRHA

¹ Department of Biology, Georgetown University, Washington, D. C. 20007
² Dermatology Branch, National Cancer Institute, Bethesda, Maryland 20014

A survey of the epidermal and gastrodermal surfaces of the scyphopolyp Chrysaora quinquecirrha by scanning electron microscopy reveals that all epithelia are ciliated to varying degrees. Cilia are surrounded at their bases by microvilli which vary in configuration. These microvillar configurations are characteristic in different areas of the polyp. Cilia with broad conical bases, corresponding closely in distribution with nematocysts, are thought to represent cnidocils.

Cilia on the epidermal and gastrodermal surfaces are responsible for the generation of a continuous current which flows in an aboral to oral direction in both feeding and non-feeding conditions. The strongest currents are observed along the free edges of the gastric septae, which are the regions of heaviest ciliation in the polyp. Externally, such currents aid in the removal of silt and debris in relatively sessile polyp and serve to circulate gastrovascular fluid and to remove undigested materials.

This work was supported by a grant ES00854 from the National Institutes of Health to the senor author.