In that context , the difference between prawn and a shrimp is usually that prawn are larger than shrimp . The term `` prawn '' is also used in various contexts for other animals , especially caridean shrimp . They are found worldwide and include commercially significant species , such as the whiteleg shrimp Litopenaeus vannamei , Atlantic white shrimp Penaeus setiferus , Indian prawn Fenneropenaeus indicus and tiger prawn Penaeus monodon .