Dear Dr. Dhruba Jyoti Sarkar, Shrimps are an extremely good source of protein, yet are very low in fat and calories, making them a very healthy choice of food. Shrimp are widespread, and can be found near the seafloor of most coasts and estuaries, as well as in rivers and lakes. There are numerous species, and usually there is a species adapted to any particular habitat.
There are a number of publications done on chemical composition of shell and flesh. I have tried to attach the very important ones here under. Please have a look in to them. I hope they will help you much for your study.