ELECTRON MICROSCOPICAL STUDIES ON THE DEVELOPMENT OF BABESIA-CANIS (SPOROZOA) IN THE SALIVARY-GLANDS OF THE VECTOR TICK DERMACENTOR-RETICULATUS

  • 1 January 1979
    • journal article
    • research article
    • Vol. 36  (3) , 229-241
Abstract
The formation of sporozoites of B. canis (a blood parasite of dogs) was studied by light microscopy and EM in the salivary gland cells of adult female ticks D. reticulatus from the 2nd day after attachment until 1 day after detachment. Sporozoite formation was initiated by the binary division of kinetes. During division, the kinetes (15 .times. 2.5 .mu.m) lost their typical organelles, reduced their 3-layered pellicle to a single membrane and became spherical. After nuclear division and a further time-lag, cell division occurred giving rise to 2 cells in which this process was repeated. After numerous binary divisions the parasites acquired more and more closely the shape of the later infectious, pyriform sporozoite. These sporozoites measured about 2.5 .times. 1.5 .mu.m, had a 3-layered pellicle, rhoptries and a few micronemes, but no spherical bodies. The development process took 2-3 days. Transmission of the parasite to the dog probably occurred while the tick engorge. The blood meal is probably the stimulation for parasite development. The cytological features of B. canis were compared to those of Theileria spp.