Determination of the median lethal concentration of water hyacinth (Eichhornia crassipes Mart. Solms) using brine shrimp lethality assay.

     This study entitled "Determination of the Median Lethal Concentration of Water Hyacinth Eicchorniacrassipes Mart. Solms.using the Brine Shrimp lethality assay" aimed to determine the concentration of the Water Hyacinth extract that would bring about death to half of the total sample of the test animal, the brine shrimp. In extracting the plant sample, the soxhlett continuous extractor was used with methanol as the solvent. The resulting extract was further concentrated with continuous heating over a water bath until there was only a semi-solid extract left. The presence of the constituents that causes the toxic effect was determined using two test tube methods, the Bate-Smith and Metcalf method and the Wilslatter "cyanidin" test. Both confirmatory tests yielded positive results for the presence of leucoanthocyanin and cyanidin respectively. The extract was then diluted in filtered sea water in appropriate amounts to make the corresponding test solutions: Test Solution A with 10 mcg/ml, Test solution B with 100 mcg/ml, Test Solution C with 1000 mcg/ml and Test Solution D , the control solution, with no concentration of the plant extract. The brine shrimp eggs were then left to hatch in a Brine Shrimp Hatchery for a period of one day and readied for subjection to the Brine Shrimp Lethality Assay. Test solutions in the Brine Shrimp Lethality Assay had eight test tubes representing per trial. Each Test tube contained ten brine shrimps. These test tubes were left to stand for a day. After which, the numbers of dead brine shrimps were counted by the researchers and was cross checked by the mentor. The results were tabulated and subjected to statistical treatment. This study used a randomized controlled experimental design in the Brine Shrimp Lethality Assay and used the program IPM SPSS ver.22 that has a Probit analysis function to evaluate the median lethal concentration of the plant extract.

     The study was confirmed on the widest scales when all the data were analyzed based on the observations noted. It was found out that the percent mortality of test solution A (10 mcg/ml) was 8.75%. Test solution B (100 mcg/ml) is 32.5%. Test solution C (1000 mcg/ml) is 55% and a zero percent mortality for test solution D (0 mcg/ml). There was a direct relationship on the concentration of the test solutions and the mortality of the brine shrimps. The higher the concentration, the greater mortality to the brine shrimps. Test Solution C, which had the greatest amount of Water Hyacinth extract showed the greatest percent mortality among all the test solutions.

     Using the Probit analysis and other statistical tool, we arrived to the conclusion that the Median Lethal Concentration of the extract of Water Hyacinth Eichhorniacrassipes Mart Solms. is 580.40mcg/ml. It means that at 580.40mcg/ml half of the total brine shrimp are dead.