author(s)
B Mondal and SK Das

abstract
Histopathological manifestation of castor bean seed as fish toxicant upon gastro-intestinal system of Tilapia (Oreochromis mossambicus) was investigated parallel with mohua oil cake as haemotoxic piscicidal agent in outdoor experimental tanks. Castor seed bean was proved to be an effective piscicide with activity potential comparative with mohua oil cake though the mortality rate was higher and quicker in the later. As plant derived toxicant castor bean exhibited strong histopathological lessions in intestinal mucosa and liver whereas, mohua oil cake exhibited severe respiratory distress to the test fish. Significant reduction of dissolved oxygen and concurrent increase in BOD₁ of water under both the piscicides aggravated the distress of the test fish.