- Triakidae, family Triakidae - small smooth-skinned sharks lacking spines on dorsal fins
--1 is a kind of fish family
--1 is a member of
--1 has members:Elasmobranchii, subclass Elasmobranchii, Selachii, subclass Selachii Mustelus, genus Mustelus; smooth dogfish; Triaenodon, genus Triaenodon