We are offering fresh prawns buy fresh fish at www.machimarket.com prawns and shrimps belong to the same family as crabs and lobsters and are similar in a number of ways. They are decapod crustaceans, which means that they have 10 legs and a hard shell covering their body, although the shell that covers prawns and shrimps is much thinner and not as hard as the shell of most other crustaceans.