Glass Cover Slip Technique for Studying In vitro Interactions between Giardia Trophozoites and Host Leukocytes by TEM, SEM, and Light Microscopy

Abstract

ably influenced by the size as well as the number of mature nematodes. The number of mature worms in 9-year-old fish from Burchell Lake was almost 7 times higher than in similarly aged fish in Greenwater Lake (Black and Lankester, 1981, loc. cit.). In comparison, fish from Burchell Lake had only twice as many swimbladder lesions. The larger size of worms in fish from Greenwater Lake may have contributed to the comparatively high number of lesions in the lake trout from this lake. The cause of the lesions is unknown. Worms do not attach to the wall of the swimbladder nor is there any difference in the morphology of the anterior end between fourthand fifth-stage nematodes (Black and Lankester, 1980, Can. J. Zool. 58: 1997-2005) which would suggest a difly influenced by the size as w ll as the number ference in feeding habits between juvenile and adult worms. Lankester and Smith (1980, Can. J. Zool. 58: 1298-1305) reported that a tangled ma s of C. farionis Fischer, 1798 was invariably associated with lesions in the swimbladder of rainbow trout, Salmo gairdneri. These observations suggest that swimbladder lesions may develop as a result of chronic mechanical irritation caused by mature worms congregating, possibly to mate. Drs. R. C. Anderson and M. W. Lankester provided valuable comments on the manuscript. The work was supported by the Natural Sciences and Engineering Research Council of Canada (NSERC) through operating grants to RCA and MWL and an NSERC Post-graduate Scholarship to GAB.