
AILMENTS AND DISEASES 

diseases of fishes. They have not received much attention from Bacteri- 
ologists and but few have been identified. 
Lymphosporidium trutte produces a dis- 
ease in aquaria and among domesticated 
fishes not yet observed in wild ones from 
natural waters. The bacteria, Fig. 101, are 
short rodlike micrococci which grow out into 
filaments, and infest the gills, blood, muscles, 
skin and surface generally. This micrococcus ee Boe ee ge A 3 
is usually present in cases of Autotoxine of 2: Greatly enlarged Blood corpuscles 
d and Bacteria. 

eq nay 
aquarium fishes. Healthy fishes succumb 
to the bacteria in a few days when inoculated beneath the skin and after a 
longer time by mixing cultures with their food. It is to be hoped that 
future investigations will familiarize the fish-culturist with many other of 
these bacterial causes of fish diseases, and with methods for their destruc- 
tion. 
Sporozoa. This section of the Protozoa includes orders which 
contain many parasitic genera. The orders of the Cytosporidia are the 
Gregarinida, Coccidiida, Hemosporidiida and Gymnosporidiida. The orders 
of Myxosporidia are the Phenocystida and Microsporidiida; and in addition 
to these are the orders Sarcosporidia, Amebosporidia and Serumsporidia. 
GreGARINIDA. Of this order none of the genera have been found 
as parasites on freshwater fishes or amphibia. 
Coccipirpa.- The freshwater parasites of this order belong to the 
genera Rhabdospora and Coccidium. R. thélohani have been found in the 
intestines of the perch, the ovarian tissues of the pike-perch, and in the 
liver of the stickleback; C. metshinkovi in the intestines of the goby; and 
C. gasterostei in the liver of the stickleback. None have been found on 
the Cyprinide. 
FIG. 102.  Myxobolus sp. incert, a Sporo- 
zoan parasite of the Goldfish and other Cyprinidz. 
Greatly enlarged. 
1. Cyst in cuticle and tissues. 
2. Cyst containing vacuoles. 
3. Ruptured cyst and escaping vacuoles. 

FIG. 102a. Head and shoulder of a Goldfish 
affected with Myxobolus sp. incert. 

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