The credit of being the smallest shark goes to "dwarf lanternshark". It is a little-known species of dogfish shark in the family Etmopteridae. Dwarf Lanternshark was discovered as recently as 1964 and its scientific name is Etmopterus perryi, named after noted shark expert Perry Gilbert. It has a maximum known length of 21.2 cm only, smaller than a human hand. Dwarf Lanternshark can be identified by its long flattened head, small size at maturity a mid-dorsal line and pattern of black ventral markings. While the markings near the pelvic fin emit chromatophores, some of these markings emit photophores which help them blend in the environment. The degree of impact from human activities on its population is unknown but could be threatened by death from bycatch.
The lantern shark as a unique camouflage to help protect it from its many predators. The shark’s underbelly is bioluminescence. This creates a light under the shark’s belly. Scientists also believe this light may be a way for the sharks to interact with one another. It is also believed that a specific hormone causes the light effect in this shark species. They have often been called the glowing shark and the glow-in-the-dark shark. They got the name "Lanternshark" from light-emitting on its sides and abdomen.
It is known to be present only on the upper continental slopes off Colombia and Venezuela and in deep water – approximately 283-439 metres down. They live at such great depths, they are hardly seen by man unless they are accidentally fished out of the waters. Their heads take up almost a third of their bodies, and their eyes are huge in proportion to the rest of their bodies. These big eyes help them to see in the dark. Their mouths are filled with 55 to 68 tiny teeth, perfectly designed for cutting and slicing. There are 25 – 32 rows of teeth in its top jaw and 30-34 rows of teeth in its bottom jaw. Krill, shrimp, zooplankton, and smaller fish make up most of the diet of Dwarf Lanternshark
Dwarf Lanternshark gives birth to 2-3 pups at a time and reproduce by aplacental viviparity. Nothing is actually known about the scarcity of this fish with this low rate of reproduction. They have a lifespan of 20 - 30 years. Other lanternsharks belonging to the same family include Velvet belly lanternshark, Caribbean lanternshark, Brown lanternshark, Broadbanded lanternshark, Fringefin lanternshark and Combtooth lanternshark.