3 1 6 Sporozoa 



loid nuclei of the sporoplasm. According to certain other reports, nieiovsis 

 occurs at an earlier stage so that all nuclei of the sporoblast are haploid, 

 and a haploid cycle with the zygote as the only diploid stage also has been 

 reported (99). 



According to Kudo, who has published a check-list of species (72), the 

 Myxosporida may be divided into three suborders on the basis of form 

 and structure of the spores. In the Eurysporina the sutural plane is ap- 

 proximately perpendicular to the major axis of the spore, there are two 

 polar capsides, one on each side of the sutural plane, and there is no 

 iodinophilous vacuole. The Sphaerosporina have spherical spores with 

 one, two, or four polar capsules and no iodinophilous vacuole. In the 

 Platysporina, the sutural plane coincides with, or approximates, the major 

 axis of the spore, there are one, two, or four polar capsules, and an 

 iodinophilous vacuole may or may not be present. More recently, Tripathi 

 (132) has suggested division of the Myxosporida into a "Suborder Uni- 

 polaria," with the polar capsules at or near one end of the spore, and a 

 "Suborder Bipolaria" with one polar capsule at each end of the spore. The 

 "Bipolaria" would include the Myxidiidae. 



Suborder 1. Eurysporina 



Family 1. Ceratomyxidae. Most known species are coelozoic parasites 

 of marine fishes and are assigned to three genera: Ceratomyxa Thelohan 

 (Fig. 6. 28, M), Leptotheca Thelohan (70; Fig. 6. 27, A, C-F), and Myxo- 

 proteus Doflein (Fig. 6. 28, G). 



Family 2. Wardiidae. Histozoic or coelomic parasites of fresh-water 

 fishes are included in this group, which contains two genera, Mitraspora 

 Fujita (Fig. 6. 28, H) and Wardia Kudo (Fig. 6. 28, F). 



Suborder 2. Sphaerosporijia 



Fatnily 1. Chloromyxidae. In the only known genus, Chloromyxum 

 Mingazzini (Fig. 6. 28, J, K), the spore contains four polar capsules. 



Family 2. Sphaerosporidae. Spores with two polar capsules are found in 

 Sijiuolinea Davis (Fig. 6. 28, O) and Sphaerospora Thelohan (Fig. 6. 28, 

 C, D). 



Family 3. Unicapsulidae. A single polar capsule is characteristic of the 

 only genus, Unicapsula Davis (Fig. 6. 28, A). 



Suborder 3. Platysporina 



Family 1. Coccomyxidae. In the only genus, Coccomyxa Leger and 

 Hesse (Fig. 6. 28, I), the spore contains one polar capsule and no iodino- 

 philous vacuole. 



Family 2. Myxidiidae. The spores contain one polar capsule at each end. 



