Have these fishermen just caught a giant
fish head that’s still alive?
That’s a sunfish or mola,
the largest bony fish in the ocean.
And no, it has not lost its lower half
to a horrible shark attack.
That’s the whole fish right there.
We promise you the whole fish and nothing but the fish.
So swim along.
Molas get their name from the Latin word for millstone.
That is a pretty good description of these
bizarre marine mammoths.
Like the goldfish in your fishbowl,
Molas are bony fish.
But they can get as heavy as 2.3 tons.
That’s heavier than three cows.
Their back fin doesn’t grow out as they mature.
Instead, it changes shape
and folds inwards over time
making the Mola look like half of a massive fish.
Five types of molas live in tropical
and temperate ocean waters.
A strange love for sunbathing runs in their family.
That’s why molas are sometimes called sunfish.
But we’ll get to that later.
The two largest and heaviest types of Molas
are the Mola alexandrini
and the Mola mola.
So big they named it twice.
"Big. Huge."
This behemoth on the fishing ship is a Mola alexandrini.
A 2.7 m (8 ft 11 in) large Mola alexandrini
caught off Kamogawa, Chiba, Japan in 1996
holds the Guinness World Record
for the heaviest bony fish.
It weighed 2.3 tons.
With further sightings across the globe, the Mola mola
and the Mola alexandrini are competing
head-to-head for the heaviest and largest bony fish titles.
But what makes them grow so large?
The Chinese Academy of Science found that sunfish
have an overactive insulin-like
growth-inducing gene.
Captive sunfish can gain over 400 kg (880 lb)
in 15 months.
These fish reach the massive size of
3 m (10 ft) in about 20 years.
And juvenile ocean sunfish gain as much as
0.82 kg (1.8 lb) per day.
That high rate of growth makes sense
since they start so small.
A Mola mola egg is about 0.13 cm (0.05 in) in diameter.
At 0.25 cm (0.1 in), a larva is the size of two grains of sand.
And since we’re in the mood for extremes,
here’s another one.
A female sunfish lays
300 million eggs each breeding season.
That’s more eggs than any other vertebrate lays.
But it’s not easy being a lonely giant in the ocean.
The Mola’s skins are home to over 40 types of parasites,
and some of them have parasites too.
Talk about a nightmare within a nightmare.
Sunbathing for hours is the fishes' solution
to this pesky problem.
They lie on their sides to let seagulls
pick off their parasites.
These 2-ton fish also vault 3 m (10 ft) in the air
so the force of hitting the water can remove parasites.
Mola molas eat about 1-3% of their body weight
in jellyfish and other gelatinous zooplankton daily.
Among the many adverse effects of climate change,
the rise of jellyfish populations has threatened
the balance in marine ecosystems.
Mola molas are a critical link in the food chain
and keep jellyfish populations in check.
The sunfishes' intestines have thick walls
that protect them from jellyfish stings.
To protect their eyes while hunting, Mola molas
pull their eyeballs into their sockets.
Well that's convenient.
Gentle and harmless to humans,
these weird, comical creatures
are at risk of choking on plastic bags
that they mistake for jellyfish.
Mola molas are often hunted for alleged medicinal uses
and killed as bycatch by large trawlers.
The International Union for Conservation of Nature
classifies them as "vulnerable".
Unfortunately, Mola molas aren't the only creatures
affected by ocean pollution.
Do you know that hermit crabs are replacing their shells
with garbage?
Check out that episode to learn more.
Growing to ginormous proportions
and sunbathing on the ocean surface
is what Molas do.
And that’s why they are Crazy Creatures.