358 

 TRYPANOSOMES OF FISH 



The number of trypanosomes described in fish 

 is very large. Here, again, indifferent male and female 

 forms are described. 



Mode of Transmission. The trypanosomes of fresh- 

 water fish are transmitted by leeches, e.g., by those of 

 the genus Piscicola and Hemiclepsis, and the trypano- 

 somes are said to undergo a complex developmental 

 cycle in the leech. The trypanosomes of saltwater 

 fish are transmitted by leeches of the genus Hemibdella 

 and Pontobdella. Leeches commonly contain flagellates, 

 probably natural to them (cp. p. 361). 



As an example of fish trypanosomes we may give : 



I. T. granulosum. In the eel (Anguilla vulgaris). 

 They vary in size from 44-80/4 in length, and 2*5-3/4 in 

 width. - Very active in their movements. Undulating 

 membrane broad. Posterior end sharply pointed. 

 Stained specimens show large chromatic granules. 

 They live in blood kept at a temperature of 10 to 19 C. 

 for a week. Transmission is effected by leeches 

 (Hemiclepsis marginata) ; the incubation period being 

 about five days. 



TRYPANOSOMATA OF FISH 



T. abramis in Abramis brama, T. cobitis in Cobitis fossilis, loach 



bream T ' . cotti in Coitus bubalis 



T . acerinae in Acerina cernua, T. angolensis in Claris angolensis 



pope T . clariae in Claris spp., China 



T. barbatulae in Cobitis barba- T. danilewskyi in Cyprinus 



tula, loach carpio 



T. barbi in Barbus fluviatilis T . delagei in Blennius pholis 



T. botbi in Bothus rhombus, brill 7". elegans in Gobio fluviatilis 



1 . carassii in Carasjius carassius, T. flesi in Flesus vulgaris, Rounder 



carp T. gobii in Gobius niger 



T. callionymi .in Callionymus T. langeroni in Cottus gobio, 



dracunculus miller's thumb 



