When it hatches, a Mola mola is the size of a pinhead but will grow to be the heaviest bony fish in the ocean—and the weirdest.
The weirdness begins with the eggs. A female Mola mola or ocean sunfish produces more eggs than any other vertebrate on earth.
One modest-sized female had an estimate 300 million eggs inside her.
At birth, the baby fish are protected by a star-shaped transparent covering that looks like someone put an alien head inside of a Christmas ornament—albeit a very small only a tenth of an inch across.
Even as a baby, the Mola mola has its parents’ surprised look with the wide eye and open mouth.
The baby will grow fast. Very fast. One individual in the Monterey Bay Aquarium gained 822 pounds in just 15 months (almost 2 pounds a day).
By the time it is an adolescent, the fish will have not tail fin, no ribs, a fused spine, and will swim by flapping its dorsal fin on the top and its anal fin on the bottom.
It will look like a giant swimming head.