824 



AQUATIC PHYCOMYCETES 



Fig. 63. Ectrogellaceae and Thraustochytriaceae 



A-B. Pythiella vernalis Couch: A, discharged sporangium in hypha of 

 Pythium; secondary zoospores beginning to emerge from cysts; B, resting 

 spore with small antheridial cell and fertilization tube. C-D. Thraustochyt- 

 rium globosum Kobayasi and Ookubo on ulotrichaceous marine alga. E-F. 

 Japonochytrium marinum Kobayasi and Ookubo: E, discharging sporangium; 

 F, biflagellate zoospore. G-H. Aphanomycopsis desmidiella Canter, in Netrium 

 digitus: G, resting spores in thallus; H, empty sporangium with two discharge 

 tubes, the latter with cysts of primary zoospores. 



(A-B, Couch, 1935a; C-F, Kobayasi and Ookubo, 1953; G-H, Canter, 

 1949d) 



APHANOMYCOPSIS Scherffel 



Arch. Protistenk., 52: 11. 1925 

 (Figs. 63 G-H, p. 824; 64, p. 826) 



Thallus endobiotic, holocarpic, branched or unbranched, broad, tubu- 

 lar, one-celled, transformed into a single sporangium; zoospores 

 diplanetic, the primary spores emerging singly without swarming motion 

 through one or more evacuation tubes and forming at the orifice a 

 cluster of cysts, the secondary zoospores laterally biflagellate, emerging 

 from the cysts through discharge tubes usually provided at their bases 



