Which shark species is the smallest in the world?

The dwarf lanternshark is generally recognized as the smallest shark species in the world. It reaches only about 20 centimeters in length, making it shorter than many people’s forearms. The species lives in deep water off parts of the Caribbean and northern South America, where it is rarely seen.

Its name refers to photophores, tiny light-producing organs embedded in the skin. These organs create a faint glow that may help the shark blend into the dim light from above, a camouflage strategy called counterillumination. The underside can appear less silhouetted against the surface when viewed from below.

Despite its tiny size, the dwarf lanternshark is a true shark, with a cartilaginous skeleton, multiple gill slits, and rows of teeth. It is not the same as the cookiecutter shark, another small bioluminescent species that is much larger and is known for taking round bites from larger animals.

Measurements can vary slightly between references, but the dwarf lanternshark remains the standard canonical answer in general-audience quizzes.