HOLOTRICHA 



709 



micronucleus adhering to macronucleus; macronucleus undergoes re- 

 organization by discarding small chromatin masses (Haas, 1934); no 

 division within the host body; multiplication within cyst which is 

 formed after dropping off the fish skin and in which numerous (up to 



Fig. 303. Ichthyophthirius ?mdtijiliis. a, free-swimming individual, X75 

 (Butschli); b-e, development within cyst; f, a young individual, X400 

 (Fouquet); g, section through a fin of infected carp showing numerous 

 parasites, XlO (Kudo); h, a catfish, Ameiurus albidus, heavily infected by 

 the ciliate (Stiles, 1894). 



1000) ciliated bodies (30-45^ in diameter) are produced; conjugation 

 has been reported; parasitic in the integument of freshwater and 

 marine fishes; in aquarium, host fish may suffer death; widely dis- 

 tributed. 



/. multifiliis F. (Fig. 303). 100-1000^ long; ovoid; produces pus- 

 tules in the epidermis or gills; cytostome is large, 30-40^ in diameter. 



