This book is the experiential results of the research problem entitled "Elucidation of the role of progesterone on metabolism, growth, and reproduction in edible freshwater crab, Oziothelphusa senex senex". The obtained results are interesting, which indicates the role of vertebrate steroid progesterone in inducing precocious ovarian development in the crab. In addition, it is also found to be involved in the regulation of growth. Based on the obtained results, it is concluded that progesterone is involved in the regulation of reproduction and molting. The obtained results further suggest that the administration of progesterone can be considered as a practical alternative to eyestalk ablation in order to induce reproduction in hatcheries of commercially important crustaceans to promote aquaculture industry.