Remarkable Molas or Ocean Sunfish

The largest fish in the world weighs over two tons, is 14 feet tall, and has bones instead of cartilage like sharks and rays. It’s the mola or ocean sunfish. The remarkable molas live in temperate and tropical oceans worldwide.

A female mola can produce up to 300 million eggs at a time. When they hatch, these fish weigh less than a gram and are 2.5 mm (.098 inches) long. The hatchlings have a back fin that folds into itself, forming a rudder called a clavus. Molas get their name from the Latin word for “millstone” because of their circular shape. They are not good swimmers using large dorsal and anal fins to move while steering with their clavus. In spite of that, molas sometimes breach, jumping 10 feet into the air to shake off parasites. Small fish help them by eating the parasites. When they are on the ocean surface, molas even allow birds to clean away the parasites. As a result, most mola sightings occur when birds are cleaning them.

Why would God create such odd fish as the remarkable molas? The answer is that molas are significant jellyfish controllers. Jellyfish have very few enemies, and left uncontrolled, they would soon dominate the oceans and become a hazard to humans. Molas are designed to be unaffected by the stinging cells of jellyfish. They have small mouths with teeth fused into a beak-like structure. This boney beak enables them to eat any species of jellyfish without being injured by their stinging cells.

In recent years, we have seen numerous cases where humans eliminate predators, throwing nature out of balance. The result is that nature becomes overrun with species previously controlled by predators. For example, here in Michigan, eliminating wolves and bears has caused the deer population to skyrocket, creating big problems for humans.

People are the worst enemies of the remarkable molas. When we discard plastic bags, they often end up in the ocean, where molas mistake them for jellyfish and swallow them, resulting in suffocation. So once again, we must manage what God has given us more carefully. If we don’t, the result can be catastrophic.

— John N. Clayton © 2022

Reference: Zoological Journal of the Linnean Society 182 (3) 631-658