Phylum：Chytridiomycota　>>　Class： Chytridiomycetes　>>　 Order： Chytridiales 
   
 
　BCRC Number： NO BCRC Number!  
   
　Scientific Name： Rhizophydium sphaerocarpum var. spirogyrae
 
   
   
　Author：

Rhizophydium sphaerocarpum var. spirogyrae D. J. S. Barr, Can. J. Bot. 48:1607-1071, 1970.
   
 
 
 
 
　Description： On Spirogyra: Sporangium epibiotic, spherical. Rhizoid endobiotic, arising from a main axis and tapering extending on Spirogyra cell. Zoospores discharge through wide apical portion, forming a temporarily vesiculate motionless group, operculum occasionally seen, become motile after discharge, soon swimming away. Zoospore spherical, 3.5-5 μm diam., flagellum about 25 μm long.On 1/4 YpSs agar: Sporangia spherical, 7.5-47.5 μm diam., or ovate. Rhizoidal system with main axis, 3-7 μm diam., branch long, sparse. Zoospores discharge through wide apical portion, about 7.5-15 μm diam., sometimes with operculum beside exit pore. Zoospore spherical, 4-5 μm diam., with a lateral refractory globule. Resting spore not observed. Color of colony buff to pale-yellow.
 
 
 
 
 
　Specimens：

Taiwan. Taipei: Yangmingshan, stream water, 21 Jul 1993, NTNU 1302.Isolated from Spirogyra in water.
 
 
 
　Habitat： Fresh water.
 
 
 
　Distribution：

Canada, Taiwan.
 
 
 
　References：

Barr, DJS. 1970; Chen, SF et al. 2000; Huth, K. and Gaertner, A. 1973.
   
   
   
　Provided：

S. F. Chen
 
 
　Note： This isolate is morphologically similar to Rhizophydium spherocarpum. Three varieties of R. sphaerocarpum are proposed (Barr, 1970; Huth and Gaertner, 1973). The physiological tests on our isolate indicate that the maximum temperature for growth is nearly 45°C. Compared with R. sphaerocarpum var. sphaerocarpum, they differ primarilly in the range of growth temperature. Moreover, our isolate is parasitic on Spirogyra, but also can be cultured on artificial medium. It is different from R. sphaerocarpum var. rhizoclonium (Huth andGaertner, 1973) in its host, and from R. sphaerocarpum var. sphaerocarpum in being unable to grow on pine pollen.