ABSTRACT
Lung fluke, Paragonimus heterotremus, is a flatworm causing pulmonary paragonimiasis in cats, dogs, and humans in Southeast Asia. We examined the ultrastructure of the testis of adult P. heterotremus with special attention to spermatogenesis and spermiogenesis using scanning and transmission electron microscopy. The full sequence of spermatogenesis and spermiogenesis, from the capsular basal lamina to the luminal surface, was demonstrated. The sequence comprises spermatogonia, spermatocytes with obvious nuclear synaptonemal complexes, spermatids, and eventual spermatozoa. Moreover, full steps of spermatid differentiation were shown which consisted of 1) early stage, 2) differentiation stage representing the flagella, intercentriolar body, basal body, striated rootlets, and electron dense nucleus of thread-like lamellar configuration, and 3) growing spermatid flagella. Detailed ultrastructure of 2 different types of spermatozoa was also shown in this study.
Subject(s)
Animals , Male , Microscopy, Electron, Scanning , Microscopy, Electron, Transmission , Paragonimus/physiology , Spermatogenesis , Spermatozoa/ultrastructure , Testis/ultrastructureABSTRACT
The migration route and the development of P. siamensis obtained from S. juliae and S. germaini were studied in B. indica. The infection rates of P. siamensis in these 2 species of crabs were 19.7% and 21.4% respectively. Worms were recovered in the abdominal cavity, pleural cavity and lungs on day 12, 16 and 30 respectively after oral infection. Worms became mature and laid eggs on day 47 after infection, but their size still increased considerably. The average egg output was found to be 144 eggs/gm faeces/worm or 443 eggs/day/worm. The average recovery rate of P. siamensis in the experimental B. indica was 15%.