Hi, I'm Danielle Dufault and you're watching Animalogic. The mola mola, or oceanic sunfish, is the largest bony fish in the world, weighing between 200 and 1000 kilos and measuring up to 1.8 metres long and 2.5 metres tall.

Some extreme cases have found especially giant mola molas weighing over 2 metric tons and measuring over 4 metres tall.

This massive size makes them almost immune to predators.

The only creatures daring enough to take them on are sharks, orcas, sea lions, and of course, us humans. Sea lions have been known to hunt mola mola, seemingly just for fun.

They'll tear off their fins, throw them around, and when they've eaten enough or gotten bored, they'll leave the mola mola to sink to the bottom of the ocean and die.

Some evidence shows that mola molas have very little in terms of pain receptors, or at the very least, don't seem to respond to an attack.

Seals and other animals have been observed snacking bites out of them, and they don't seem to have a care in the world.

They just carry on with that vacant stare. Mola molas can be found in warm and temperate waters around the globe, tolerating waters as cold as 2 degrees Celsius.

When they get too cold, they swim to the water's surface to warm up by sunbathing.

When you think prehistoric animals, one common theme probably comes to mind: Giant!

Interestingly enough, mola mola are members of the Molidae family, which, despite their prehistoric-looking giant size, might have you believe, are actually one of the youngest fish families in the ocean, appearing roughly 50 million years later than most modern fish. For years, mola mola were believed to be plankton, as they were thought to be too slow to move independently.

I don't think evolution or phylogeny was too understood at the time.

But more recently, they've been discovered to be...

not speedy swimmers.

What's the word I'm looking for?

Swimmers.

Just swimmers.

They have been documented reaching the breathtaking top speed of 3 kilometers an hour.

While that might seem slow, it's fast enough to give them the momentum they need to launch themselves out of the water. To get around, they have a pseudotail, called a clavus, which instead of being formed by the typical caudal fin, is formed by elements of their anal and dorsal fins, and functions much like a rudder.

They have four teeth, which are fused together, that form a sort of beak, which they can never quite fully close.

Their throats are lined with pharyngeal teeth, which they use to shred and grind sea jellies, salps, ctenophores, and Portuguese man o' war that they eat. Juvenile mola molas are much less picky eaters and will essentially eat anything that they can catch.

This diet of creatures that look like billowing plastic bags has led to a serious problem for the mola mola: actual plastic bags.

As we keep using the oceans as our personal garbage bins, more and more mola mola are accidentally eating plastic bags, which, to a two-ton behemoth with the brain the size of a walnut, look a lot like their regular dinner of sea jellies.

The bags will either clog their gills and suffocate them or get caught in their digestive system and slowly kill them from the inside. Mola mola are very docile creatures and pose no threat to humans, except maybe size envy.

Though there have been some reported cases of mola mola jumping onto fishing boats, which can be dangerous due to their massive size.

In 1998, a cement carrier ship, the MV Goliath, arrived at the Sydney harbour with a mola mola impaled on its bow.

The fish was so large that it slowed the ship's cruising speed from 14 to 11 knots. Being so large, their scaleless, mucus-covered bodies can be home to up to 40 kinds of parasites.

Because of this, they form symbiotic relationships with kelp and half-moon fish, which feed on their parasites.

When those aren't enough, mola mola will swim to the surface and float horizontally for seabirds to feast on their parasites.

These parasites offer some interesting insights into their interspecies associations.

One of the common mola mola parasites is the larval stage of a shark tapeworm.

Meaning that the tapeworm will grow inside the mola mola with the hope that it'll one day be eaten by a shark, where it can reproduce and then start the whole process over again. Mola mola are caught primarily as bycatch but are a delicacy in East Asia, with their guts being sold as dragon intestines.

Some scientists believe their guts are poisonous, which is why they're illegal to consume in the EU, while others believe they aren't, thus their popularity in Asia.

Could use a bit more research. Mola mola lay more eggs than any other vertebrate, laying up to 300 million in one go.

When they hatch, they're about the size of a pinhead and resemble their cousins, the pufferfish.

Though instead of spikes, they're protected by a star-shaped cover. What animal should I check out next?

Please let me know in the comments, and be sure to subscribe for new episodes of Animalogic every other week.

Thanks for watching!