Ocean Sunfish:
The Mola mola—which looks like a prehistoric shark that lost a tail in an epic battle—might be the world’s weirdest fish. Here are just a few reasons it’s the most fascinating marine creature around.
1. They love to sunbathe.
Sunfish spend up to half the day basking in the sun near the surface of the water, which helps warm their bodies up after deep water dives to hunt.
2. They can weigh more than a car.
The average ocean sunfish is 10 feet long and weighs 2200 pounds, but the biggest can grow up to 5000 pounds. The average pickup truck is only 4000. This makes them the world’s largest bony fish.
3. They lay more eggs than any other animal.
Sunfish can lay up to 300,000,000 eggs at one time, more than any other vertebrate.
4. They are related to the bass.
Largemouth bass, smallmouth bass, rock bass, and black bass are all members of the sunfish family. Bass generally eat the smaller members of the sunfish family, like bluegills.
5. They’re named after a millstone.
The name Mola mola comes from the Latin word for “millstone.” It’s named for its gray, round body, and rough texture.
6. They can dive up to 2600 feet. 
Sunfish generally hang out at depths of 160 to 650 feet, but they can dive much deeper on occasion. In one study, scientists recorded a sunfish diving more than 2600 feet below the surface.
7. They’re voracious predators.
Scientists used to think that sunfish were relatively inactive, spending their days sunbathing and feeding on jellyfish. However, despite their doofy appearance, sunfish are active predators with discerning tastes who travel several miles per day. In a recent study, scientists observed sunfish feeding solely on the most energy-rich parts of jellyfish—the gonads and the arms—while leaving the less nutritious bell behind. They also occasionally eat small fish and zooplankton.
8. They were an acceptable form of tax payment in 17th century Japan …
During the 1600s and 1700s, Japanese shoguns accepted Mola mola as payment for taxes.