Manjula, U.D.P.2021-03-182021-03-182012UWU/ANS/08/0022http://www.erepo.lib.uwu.ac.lk/bitstream/handle/123456789/6131/UWULD%20ANS%2008%200022-09042019091730.pdf?sequence=1&isAllowed=yFish glue is water soluble hydrophilic colloidal proteins derived by controlled hydrolyzation of water insoluble collagen. The yellow fin tuna and Mahi-mahi fish glue was prepared by extracting gelatin from fresh and frozen skin by alkaline pretreatment followed by acid extraction method. Different acid and alkaline concentrations (0.1 %, 0.2 % and 0.4 %) and soaking time (18 hours, 24 hours for YFT and 1 hour, 3 hours for MM fish skin) were used for different fish glue type extraction. The proximate composition of the YFT and. MM fish skin were 39.1% moisture, 60.95% crude protein, 10.51% crude fat and 2.4% crude ash and 33.8% moisture, 46.73% crude protein, 5.83% crude fat and 6.7% crude ash respectively. The physical and chemical properties of the fish glue such as proximate composition, open time, Bonding power, pH, color, and yield were determined separately based on the changes in concentration and soaking time. The best acid and alkali concentration and soaking time for YFT skin was 0.2 %, 24 hours soaking time. While for MM skin it was o,4 %, 3 hours soaking time at 60 °C. The variance between glue sample of YFT and MM due to changes of acid and base concentration and soaking time did not show any significant variance except open time (p<0.5).The YFT and MM glue works better on wood tacking and glass tacking purposes.enAnimal Science Degree ProgrammeThesis