Date of Award

2010

Thesis Type

Masters

Document Type

Dissertation

Divisions

Faculty of Science

Department

Institute of Biological Sciences

Institution

Universiti Malaya

Abstract

Three sampling stations with various environmental quality gradients in Ulu Gombak Forest Reserve, Selangor, Peninsular Malaysia were selected in this study: Sungai Gombak, Anak Sungai Gombak and Sungai Batu 19. A total of six genera of ephemeropteran nymphs were found from the mentioned streams: Baetis sp. (Baetidae) (232), Thalerosphyrus sp. (Heptageniidae) (925), Campsoneuria sp. (Heptageniidae) (1432), Neurocaenis sp. (Tricorythidae) (471), Platybaetis sp. (Baetidae) (12) and Prosopistoma sp. (Prosopistomatidae) (1). The most dominant family of ephemeropteran nymphs is Heptageniidae while Neurocaenis sp. (Tricorythidae) were the only nymphs that showed significant difference in abundance between all three streams (p=0.05) using student t-test. Margalef’s Richness Index suggested that Sg. Gombak has the highest diversity of ephemeropteran nymphs (0.66), where as Shannon’s Diversity Index and Simpson’s Index of Diversity showed the diversities were the same in Sg. Gombak and Anak Sg. Gombak. Eight physicochemical parameters (illuminance, pH, water temperature, dissolved oxygen, conductivity, nitrate, phosphate and ammonical nitrogen) were measured for the purpose of assessing water quality and abiotic parameters at the study area and evaluating the potential of mayfly nymphs’ abundance and environmental parameter correlation. Results of the water quality study showed that the various sampling stations had different values with regards to the Interim National Water Quality Standards for Malaysia (INWQS). pH was the only environmental parameter that showed a statistically significant positive linear association with the abundance of mayfly nymphs in all three streams (Sg. Gombak: r=0.57, p=0, Anak Sg. Gombak: r=0.64, p=0 and Sg. Batu 19: r=0.64, p=0). Control strains of Baetis sp. and Campsoneuria sp. nymphs were chosen for biochemical assay. The difference in protein content between both Baetis sp. And Campsoneuria sp. were found to be insignificant (p=0.29). Three biochemical enzymes activity for non-specific esterase, acetylcholinesterase and glutathione-s-transferase was studied. The in vitro inhibition potency of organophosphate pesticides (Dichlorvos, Malathion and Fenitrothion) and heavy metals (mercury, cadmium, lead and copper) on non-specific esterase and acetylcholinesterase extracted from Baetis sp. and Campsoneuria sp. nymphs were compared. All the tested compounds exhibited high inhibition potency to non-specific esterase and acetylcholinesterase of Campsoneuria sp. than Baetis sp. With Dichlorvos being the most potent inhibitor. Acetylcholinesterase bimolecular rate constants (Ki) were measured for each inhibitor compound with different concentrations for both Baetis spp. and Campsoneuria spp. The bimolecular inhibition rate constant value of Dichlorvos (DDVP) for both Baetis sp. and Campsoneuria sp. were significantly higher than other tested inhibitors, with p=0.03 using student t-test.

Initial

khm

Additional Information

Dissertation (M.A.) – Faculty of Science, Universiti Malaya, 2010.

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