369) STUDIES ON MYXOSPORIDIA—KUDO 131 



MYXOBOLUS TOYAMAI Kudo 

 [Figs. 369 to 370] 



1915 Myxobolus toyamai Kudo 1915 : 517-523 

 1917 Myxobolus toyamai Kudo 1917 : 163-170 



Habitat: — Connective tissue of branchial lamellae of Cyprinus carpio 

 L.; Tokio (July). 



Vegetative form : Cysts, ovoidal or in shape of calabash. Small form 67 

 by 50m, shows clear differentiation of protoplasm. Ectoplasm radially 

 striated, often, differentiates fine processes (2 to 3ix long). Endoplasm 

 coarsely granular, contains nuclei from 1 to 4fx in diameter. Size up to 190/x 

 in greatest diameter in sections. Two spores are formed in each pansporo- 

 blast. Polysporous. 



Spore: Pyriform, with attenuated anterior and rounded posterior ends. 

 No bilateral symmetry. Lateral sides are curved. Calabash shaped 

 spores often occur. Shell without any marking, thickened at the anterior 

 end. Sutural ridge shows sometimes a short (1.5^* long) tail-like process at 

 the posterior tip. A single pyriform polar capsule at the anterior end; in 

 stained preparations, a small, oblong mass of protoplasm is seen between 

 the polar capsule and the shell. Coiled polar filament distinct. Sporo- 

 plasm with two nuclei of usually same size and a relatively large iodino- 

 philous vacuole, 3/x in diameter. Dimensions: length 15^, breadth 7 to 8ju, 

 thickness 5 to 6^, polar capsule 7 to 8yu by 3 to 4^i, length of polar filament 

 40 to 45/i (pressure, perhydrol, KOH). 



MYXOBOLUS NOTATUS Mavor 

 [Figs. 371 to 372] 



1916 Myxobolus notatus Mavor 1916a : 70-71 



Habitat: Connective tissue of the voluntary muscles on the sides or 

 tail of Pimephales notatus Raf.; Georgian Bay, Canada (Summer). 



Vegetative form: Cysts as large as 3mm. in diameter, are surrounded 

 by a layer of columnar epithelial cells (origin and significance?) and a dense 

 layer of connective tissue. Protoplasm is not clearly differentiated, tho 

 the cyst is surrounded by an area devoid of nuclei. In the outer region of 

 endoplasm, numerous nuclei each with a caryosome, are recognized. In 

 the course of spore formation, two nuclei for polar capsules appear at first, 

 one of which degenerates later. Polysporous. 



Spore: Pyriform, with a posterior extension forming a process, S/i in 

 length and as broad as the spore. A single polar capsule at the anterior 

 end. An iodinophilous vacuole in the sporoplasm. Dimensions: length 

 17 to 18/1, breadth 7.5 to 8)u, polar capsule In by 4/1, length of polar filament 

 95m. 



