462 



MARINE FUNGI 



taceae and Hyphochytriaceae should together be placed in the 

 new order Anisochvtridiales. 



Among- the collections by Petersen (1905) and Sparrow (1934) 

 from the coast of Denmark are listed 22 species of chytrids. Their 

 studies indicate that chytrids are the most abundant members of 



the marine fungus flora. 



h <3 



'• • v'"< r 

 i - ■ V ^W 



Fig. 76. Various marine chytrids. (After Sparrow.) A-D. Developmental 

 stages of Thraustochytridhim proliferum on Bryopsis plumosa. E. Chytrid- 

 ium polysiphoneae in thallus of Polysiphonia. F. Pleolpidium (Rozella) 

 marimtm, discharging its spores within the thallus of Chytridium polysi- 

 pkonieae. G. Sporangium of Petersenia andreei in Ectocarpus. H. P. 

 andreei, mature resting spore with empty male cyst attached. 



Perhaps the most singular member of this group that has been 

 described is Ichthyophomis hoferi, first mentioned in 1904 as a 

 parasite of certain fishes by Hofer and later studied by Plehn and 

 Alulsow (191 1) and Daniel (1933). This species causes enormous 

 losses to marine fish, particularly herring and trout. Plehn and 

 Mulsow (1911) described and named the organism, placing it 

 anions the Chytridiales. Daniel (1933) made a rather detailed 

 study of the pathogen as it occurs in the sea herring, Clupea 

 harengus. The spores are non-motile and usually multinucleate 



