Ina June F. De la Fuente, Regine Marie E. España, Andrew M. Estimo (March 2009)
Philippine Science High School Western Visayas Campus – Department of Science and Technology (DOST-PSHS WVC), Brgy. Bito-on, Jaro, Iloilo City 5000, Philippines
ABSTRACT
The use if poisonous plants to stun fish for easy capture has been a worldwide fishing technique. Up to date, details regarding the mechanisms of action of such poisons still contain gaps. Several studies have been conducted to identify the physiological effects of a certain substances on fish or on other organisms. The primary purpose of this study was to determine the physiological changes that occur in Oreochromis niloticus when exposed to Albizia procera aqueous extract in terms of erythrocyte number concentrations, hermatocrit level, hemoglobin level, and the appearance of the primary filaments, secondary lamellar, and cartilage of the gills. Two hundred milliliters of aqueous extract was equally distributed into two separate fiber glass tanks, each containing 200 L of fresh water and 30 Nile tilapias ranging from 25 to 30 g in mass. Toxic responses exhibited by the fish include initial disturbed swimming movements, rapid opercular movements, and surfacing. Blood and gill samples were obtained before and at different time intervals (30 minutes, 1 hour, 2 hours, 3 hours, and 4 hours) after the introduction of the extract. Escalating degrees of hyperplasia and separation from the gill cartilage were noted in the gill epithelia as the length of exposure to the extract increased. Gills collected after 4 hours of exposure showed the most extensive damage. As for the hematological examinations, however, all changes in the blood parameters were not significant (P>0.05).