Which shark is often cited as the smallest shark species?

The dwarf lanternshark is often cited as the smallest shark species.

The dwarf lanternshark (Etmopterus perryi) is a tiny deep-water dogfish shark reported from the Caribbean Sea off Colombia and Venezuela. It reaches roughly 20 centimetres in maximum known length, making it dramatically smaller than the sharks most people picture. Its small body, flattened head and dark underside help distinguish it from larger lanternsharks.

Despite its size, it has specialised features typical of its group. Light-producing organs called photophores cover parts of its underside, probably helping camouflage the shark’s silhouette when viewed from below. It lives on upper continental slopes, hundreds of metres beneath the surface, where direct observation is difficult.

The wording “often cited” matters because the dwarf lanternshark is not the only contender. The spined pygmy shark and pygmy ribbontail catshark reach comparably small sizes, and differences in measuring maturity, sex and maximum length make an absolute ranking difficult. For a general trivia question, however, dwarf lanternshark is the standard answer.