Developing effective institutions for water resources management: A case study in the Deduru Oya Basin, Sri Lanka

River basins / Water resource management / Water lifting / Wells / Domestic water / Population / Economic aspects / Income / Irrigation programs / Institutions / Policy / Groundwater / Agricultural development / Fish farming / Pumps / Ecology / Water supply / Drought / Poverty / Land use / Water scarcity / Natural resources / Agricultural production / Cropping systems

Localization of acid phosphatase activity in the testis of two teleostean species (Oreochromis niloticus and Odonthestes perugiae)

Acid phosphatase (AcP) activity was investigated in the testes of two species of teleosts in two seasons: summer and winter. AcP activity was detected in Sertoli cells from tilapia (Oreochromis niloticus) only during the nonreproductive period of its annual cycle, corresponding to the winter months. In kingfish (Odonthestes perugiae), the enzymatic reaction was identified during the non-reproductive period (summer) in epithelial cells of the efferent ducts but not in Sertoli cells. These data suggest that the enzyme is involved in the absorption of residual spermatid cytoplasm and as well as in the removal of spermatozoa remaining after the reproductive period. In kingfish, this heterophagous function is carried out by the efferent duct cells and not by Sertoli cells