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 Hemiclefsis , 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 : 
1. T. granulosum. —In the eel (. Anguilla vulgaris). 
They vary in size from 44-80/^ in length, and 2*5-3in 
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 0 C. 
for a week. Transmission is effected by leeches 
(Hemiclepsis marginata ) ; the incubation period being 
about five days. 
Trypanosomata of Fish 
B. abramis in Abramis brama , 
bream 
B. acerinae in Acerina cernua , 
pope 
B. barbatulae in Cobitis barba- 
tula , loach 
B. barbi in Barbus fluviatilis 
T. bothi in Bothus rhombus , brill 
T. carassii in Carassius carassius, 
carp 
B. callionymi in Callionymus 
dr a cun cuius 
B. cobitis in Cobitis fossilis , loach 
B. cotti in Cottus bubalis 
B. angolensis in Claris angolensis 
B. clariae in Claris spp., China 
B. danilewskyi in Cyprinus 
carpio 
B. delagei in Blennius pholis 
B. elegans in Gobio -fluviatilis 
B . fie si in Flesus vulgaris, flounder 
B. gobii in Gobius niger 
B. langeroni in Cottus gobio, 
miller’s thumb 
