Antibiotic resistant microorganisms have been emerging worldwide and causing serious complications today. As these microorganisms are resistant to most of the contemporary antibiotics, their control has become a global health concern. Therefore, there is a need for new alternative compounds or strategies that are effective against these microbial infections in preventing or delaying their resistance. Jharkhand (INDIA), where freshwater reservoirs are abounding in, having treasure of aquatic species rich in antibacterial substances can prove to be boon for researchers. Freshwater edible crabs (Decapoda-Crustacea) are abundantly found in the shoreline areas of the above water bodies. The present book deals about the peculiar characteristics, systematic status, biomedicinal value with special reference to antibacterial screening of the freshwater crabs, S. spinigera, M. masoniana and B. cunicularis found in Jharkhand (INDIA). Morphology, pathogenicity and different culture methods for the growth of gram positive and gram negative bacteria have also been dealt. This book also deals with the antibacterial efficacy of chitosan from the carapace of M. masoniana.