Effect of thermal acclimation on gametogenesis of the indian freshwater leech,Poecilobdella Viridis (Blanchard)

The effect of thermal acclimation for 15 days on the gametogenesis of Poecilobdella viridis was studied. Leeches conditioned at laboratory temperature (25.5°–27.5°C), when warm acclimated (32.0° ± 0.5° C), displayed a significant (p < 0.05) increase in the percentage of oocytes having a diameter of 12.5 µ and 15.0 µ and in the percentage of fully mature sperm clusters over the controls, whereas cold acclimation (10.0° ± 0.5°C) did not induce significant (p > 0.05) changes in the oocytes and sperm clusters. Thus it is concluded that in P. viridis temperature is of paramount importance in initiating gametogenesis.