What are the World’s Smallest Sharks?

04/04/2019

A quick guide to the world’s smallest sharks

Image credit: Islandjems – Jemma Craig/Shutterstock.com

Anyone with an interest in sharks knows that the whale shark is by far the largest of all the species. The colossus of the shark world, can measure over 12 m in length and weigh over 20 tonnes when fully grown. The most notorious of all sharks, the “great white”, is a lightweight by comparison. However, it is certainly still impressive enough when it comes to measuring up. The largest-ever great white shark ever recorded came in at more than 6 m long and weighed in at close to 2 tonnes.

Families of Small Shark

However, for many species of sharks, size definitely isn’t everything! For instance, did you know that around half of the 450 or so species of shark, measure less than 1 metre in length when fully mature? Most of the small shark population is made up of the 50, or so, species of lantern shark, and the 160 species of catshark. In fact, the only other sharks that features in the 20 smallest of all sharks, apart from lantern sharks and catsharks, are two species of pygmy shark.

Lantern sharks are of the Etmopteridae family within the Squaliform order of sharks. They are characterised by the light-emitting organs, called photophores, they have along their belly and fins. This provides camouflage when they feed in shallow waters, as their lit-up belly blends in with sunlight streaming down from above. In deeper darker water, the light attracts small sea creatures, which the lantern shark preys on.

Lantern sharks also tend to have larger eyes by comparison with other species of shark. This helps them see in the mostly-dark waters of the ocean’s twilight zone, where they spend much of their time. Lantern sharks as a family, are found in all oceans around the world, but some species are restricted to certain areas.

Catsharks

Catsharks are ground sharks of the Scyliorhinidae family, the largest of all shark families. There has been as many as 160 species of catshark, reported worldwide. They are found on sea beds in temperate and tropical seas worldwide, ranging from very shallow intertidal waters to depths of 2,000 metres or more. Whilst generally known as catsharks, some of the species are rather ironically, also referred to as dogfish. Like most bottom-feeders, these predators feed on tiny invertebrates and small fish.

Catsharks are characterised by their elongated, cat-like eyes and two small dorsal fins. Most species of the catshark family grow to no more than 800 mm. However a few species such as the nursehound shark, can grow up to 1.6 m. Most of the species have a patterned appearance, ranging from stripes, to patches, to spots

Pygmy Sharks

Pygmy sharks and spined pygmy sharks are Squaliform sharks of the Dalatiidae family. These sharks have a wide distribution around the world, though they seem to best prefer the amphi-temperate areas of the south Atlantic, south Indian and Pacific Oceans. They only grow to an absolute maximum of 275 mm in length. They can be found in the greatest depths of the ocean, but in any case, like to inhabit depths of not less than 1500 metres.

There isn’t a definitive chronological listing of the world’s smallest sharks, since the difference in length of the smallest species of shark is quite minimal and measurement difficult due to limited sample sizes. Accurate measurement of sample specimens is also clouded by the fact that adult male sharks are generally smaller than the female, although in some of the smaller species, it’s vice versa. Furthermore, new species of shark are still being discovered on a regular basis, about eight annually over the last decade. Most of these species are in the small shark category.

The World’s 12 Smallest Sharks

The shark generally recognised as the world’s smallest is the Dwarf Lantern Shark. When fully mature it can measure as little as 150 mm (6”) in length. Not that much bigger is the Lollipop Catshark, around 280 mm (11”) in length when fully grown. However, it is ranked as only the world’s twelfth smallest shark. Based on the current information, here’s a quick guide to the world’s twelve smallest sharks. They are presented in order with the smallest shark first: