There have been huge demands for aquaculture products over the years owing to continuous population growth the globe consistently witnesses. Marine invertebrates such as the molluscs and crustaceans are affirmed to be good source of protein. The shells of these animals however are often discarded after the edible parts are consumed; this ends up polluting the environment. A useful material that can be sourced from these shells is a natural polymer – chitin. In this study, chitin was chemically extracted from ground snail, periwinkle, crab, shrimp and prawn shells under similar isolation conditions using 1 M hydrochloric acid and sodium hydroxide. This was done to investigate the influence of each shell on the ease of chitin isolation and eventually, its properties. It was observed that property of chitin depended on features of each shell. The harder the shell, the longer it was to achieve complete demineralization as more acid volumes were consumed. A maximum volume of 2490 ml was needed for total demineralization of 150 g periwinkle while the least (1498 ml) was required for shrimp shell of the same quantity. This implied that snail and periwinkle shells contain more inorganic minerals other than the domi-nant calcium carbonate. Degree of acetylation, calculated from Energy Dispersion Spectroscopy results, was the maximum for shrimp chitin (79.9 %) while the least (61.6 %) was calculated for periwinkle chitin. Thermogravimetry Analysis showed that 47.8, 15, 60.8, 78.4 and 63.7 % chitin was yielded from periwinkle, crab, prawn and shrimp shells respectively. The highest value of de-gree of acetylation possessed by shrimp chitin was responsible for its superlative thermal stability (324.6 kJ). Average intra and intermolecular OH bonds in shrimp chitin was calculated to be 5.461 kCal, which was the highest magnitude; 4.642, 4.543, 4.696 and 4.952 kCal were calculated for snail, periwinkle, crab and prawn chitin respectively.