The common triplefin (Forsterygion lapillum) is a fish of the genu Forsterygion, found around the coast of New Zealand down to depths of about 15 m. Its length is between 4 and 8 cm. It is commonly found in intertidal rock pools.[1] It can also be found in water as deep as 30m, feeding primarily on crustaceans and polychaetes.