The Goblin Shark Has an Odd Secret Weapon: Its Oily Liver

The goblin shark's jaws, beady eyes and freakishly flat snout come together for a bizarre face reminiscent of a Picasso painting. The elongated nose in particular — paired with the retractable jaw — creates a facial proportion you don't often see, even in the deep ocean.

Three rows of around 25 crooked, needlelike teeth line the tops and bottoms of its gums. Its jaws also sit strangely on its face because of a double set of ligaments that let goblin shark extend and retract them for feeding purposes.

The rest of a goblin shark's flabby body comprises transparent, pinkish skin that gets its hue from the blood vessels that shine through. Averaging around 12 feet (3.6 meters) long, goblin sharks are hefty creatures, weighing in at about 400 pounds (181 kilograms).

Its appearance is otherworldly enough to earn it the common name of goblin shark or elfin shark, but its strange attributes are actually evolutionary adaptations. (The same goes for its wide-mouthed shark relatives, mackerel sharks.) For starters, its flat snout is lined with openings called ampullae of Lorenzini that serve as electrical sensors that track down food.

Sharks have a unique sense called electroreception. Ampullae pick up weak electrical impulses living fish and animals give off whenever a muscle contracts. This built-in homing device allows goblin sharks to seek out food. Once it's tracked down a meal, the goblin shark's retractable jaw provides the quick-draw action to snatch up food.

In spite of the goblin shark's large size, it can sneak up on prey effectively thanks to — wait for it — its liver.

In relation to body size, the goblin shark's oily liver takes up enough room on its insides to make it almost as dense as water. Since it floats so easily, the fish requires little movement to get around, and it can discretely float up to its desired food source.

Goblin sharks are considered living fossils because the species was thought to be extinct. Despite existing in modern scientific history for little more than a century, the goblin shark species is believed to go back 125 million years.

When the goblin shark species was first discovered off the coast of Japan in 1898, it set off a case of scientific déjà vu. Researchers realized that they had seen goblin sharks before — not swimming in the seas, but in fossil remains.

Shark fossils from the Scapanorhynchus species dating back more than 100 million years bore striking resemblance to the goblin shark. And the chance of the resemblance being a coincidence is low; after all, its physical features make it a pretty distinct species.

Goblin sharks are believed to have a lifespan of around 60 years, but exact information is limited due to the rarity of sightings. A comparison between the current incarnation and fossils also revealed that little about the bony fishes has changed over time.

Research conducted on the small number of goblin sharks that have come out of the water suggest that their main food sources include fish, shrimp and squid.

Deciphering more concrete dietary information has been a challenge since very few specimens caught have any stomach contents to examine. For example, in one large-scale study on goblin sharks performed in 2006, 29 percent of the 148 individual fish studied had no food inside of them.

The last goblin shark sighting occurred off the coast of Taiwan in 2023. It was a pregnant female carrying six pups. Previously, one caught in 2007 in Tokyo Bay, Japan, died after only one day in captivity.

Since such opportunities are few and far between, it may be a long time before we decode all the mysteries of the goblin shark.

These marine animals are considered living fossils, because they have either stayed relatively same for millions of years or they were thought to be extinct before they were found living again.

1. Sturgeon

The largest freshwater fish that can live beyond 100 years. also has a retractable jaw like the goblin shark. They're believed to go back to the the Middle Jurassic period, which was about 174 million to 163.5 million years ago.

2. Lamprey

Sometimes referred to as a "vampire fish" or a "prehistoric vampire of the sea," this parasitic, jawless fish kills its prey by sucking out its body fluids. Research shows that they've stayed pretty much the same for more than 340 million years.

3. Frilled sharks

These sharks, also known as "lizard sharks," resemble large eels with snake heads, and they're believed to go back 80 million years.

4. Alligator Gar

These freshwater fish, which are one of the largest in North America, are inedible to humans because their eggs are poisonous. They are believed to go back 100 million years, based on fossil records.