It is known that the extracts of various marine organisms exhibit antibacterial and antifungal activities. A number of studies has been carried out on the ecophysiology of the hemichordate Ptychodera flava of the Madras Coast. Such studies have brought to light the presence of bio-active compounds in the crude extract of the hemichordate. It has been reported that the extract, in high concentrations, inhibited the devage of the fertilized cell of the marine polychaete Hydroides elegans whereas low concentrations of the extract accelerated the devage process.

The present study was undertaken to test the antifungal activity, if any, in the crude extract of P. flava. The- fungus Pestalotia palmarum, a leaf blight pathogen in coconut palm and tea plant was choosen as the bioassay material. Using axenic cultures, the effect of the crude extract of P. flava on the fungal spore germination and mycelial growth have been investigated. Pharmacological significance of the investigation has been commented upon.