US Fish & Wildlife Service


Date of this Version



Published in Transactions of the American Microscopical Society, Vol. 72, No. 4 (Oct., 1953), pp.376-378.


In 1948 Mr. J. R. Wennemark called the writer's attention to a filamentous growth extending from the cuticle of Leidynema appendiculata and Hammerschmidtiella diesingi, oxyurid nematodes found in the intestine of the American roach, Periplaneta americana, which was collected in Iowa City, Iowa. Because of the extreme filamentous accumulation it was thought to be the mycelium of a fungus. Further observation on material from roaches reared in Grand Forks, North Dakota, and Detroit, Michigan, showed that the organism was not fungus but a member of the Actinomycetaceae. Slides were sent to Profs. R. S. Breed and H. J. Conn who agreed that the organism belonged in that group and suggested that it be placed in the genus Streptomyces. Dr. Lyell Thomas (1952) observed a filamentous organism which was not a fungus, growing on the cuticle of an oxyurid nematode in frogs. Leidy (1849) and Thomas (1930) have recorded the only known fungus, Enterobrus sp., on nematodes.