ORDER SAPROLEGNIALES 



113 



Fig. 36. Saprolegniales, Family Saprolegniaceae. (A-C) Aphanomyces exoparasiti- 

 cus Coker & Couch. (A) Encysted zoospores at mouth of zoosporangium. (B) Young 

 oogone and antherid. (C) Mature oogone containing oospore. (D, E) Aphanomyces 

 phycophilus de Bary. (D) Discharged zoospores. (E) Oogone and antherid. (A-C, after 

 Couch: J. EHsha Mitchell Sci. Soc, 41(3-4) :213-227. D-E, after Sparrow: Mvcoloaia 

 22(3):118-121.) 



has but a single egg. The species of this genus are parasitic in algae and 

 in the roots of higher plants, where they may cause root rots, as well as 

 upon some aquatic animals, mostly Crustaceans. .4. acinetophagus Bartsch 

 and Wolf (1938) has been described from a fresh-water protozoan. 

 Scarcely distinguishable from Aphanomyces is Hydatinophagus parasitic 

 upon Rotifers. Another closely related genus, also parasitic upon Rotifers, 

 is Sommersiorffia, with special spike-like branches which catch the host 



