Zoosporic marine fungi from the Pacific Northwest (U.S.A.)

Abstract

Summary. An investigation of the zoosporic fungi in the vicinity of the Friday Harbor Laboratory, San Juan Is., Washington, revealed the presence of great numbers of fungi. With one exception (Olpidium sp.) these were all biflagellate organisms. Predominating were species (11) of Thraustochytriaceae which abounded in water, in association with seaweeds, intertidal sands, and particularly on the surface of bottom samples down to depths of 298 m. A twelfth species of this group has several peculiarities and needs further investigation. Of the algal parasites, one on Polysiphonia and Pterosiphonia is considered new and termed Eurychasma ]oycei n. sp. Aside from the few fungi noted in JoH~so~ (1966), and FlYLLER, et al. (1964), little is known of the zoosporic marine Phyeomyeetes from the Pacific Northwest coast. The observations herein reported were made during a 10-week stay at the Friday Harbor Laboratory, University of Washington, San Juan Island in the summer of 1968. It is of interest to note that only one of the zoosporic fungi found belonged to the Chytridiomyeetes, i.e., those with a single posterior flagellum on their zoospore, which are so abundant in fresh water. The others were all biflagellate forms belonging primarily to the Saprolegniales. This peculiarity had previously been noted among marine Phycomycetes from the Atlantic coast of the United States and in the Carribean area (SPaRrow, 1936, 1968). Methods Algal parasites were found by direct examination of the hosts. Saprophytes such as tile Thraustochytriaceae were obtained by baiting with pine pollen debris, bottom mud or water from the various sites. Pure cultures on solid media were obtained by use of Vishniae's agar to which had been added antibiotics (FvLL]~R et al., loe. cir.). * The assistance of Drs. R. E. NonRIs and G. J. HOLLE~B:E~a in calling my attention to certain algal parasites is gratefully acknowledged. I am also indebted to my colleague Dr. H. C. W~ISL~R, and to Dr. C. ANASTASIOU for assistance in photographic work.