External morphology of Lagenidium giganteum zoospores (Oomycetes: Lagenidiales)

The external morphology of Lagenidium giganteum was studied with the aid of Nomarski differential interference microscopy, scanning electron microscopy and unidirectional shadow-casting techniques. Zoospores were ovoid, bluntly pointed and flattered on one side at the anterior end. On one side of the zoospore, a groove ran from end to end parallel to the long axis. Protruding from the groove were two flagella, a posterior whiplike flagellum and an anterior tinsel flagellum with lateral hair. Features of the zoospore surface included an irregular reticulate pattern of ridges and mounds marked by deep irregular pits scattered randomly over the zoospore surface.This investigation received financial support from UNDP/World bank/WHO Special Programme for research and training in Tropical Diseases under the Scientific Working Group on Biological Control of Vectors.Rhode Island Agricultural Experiment Station Contribution N 2287.