Marine invertebrates include all animals with no backbone that live in the marine environment. There are six main groups of invertebrates: sponges, crustaceans, mollusks, echinoderms, tunicates, and coelenterates, among others. They are protected in the Gulf of Cambay. It is a bay on the Arabian Sea coast of India, bordering the state of Gujarat. It is about 200 km long, about 20 km wide in the north and up to 70 km wide in the south.