How Clownfish Find Their Way Back to Familiar Waters

Specifically, the clownfish return to their sea anemone homes in coral reefs near shore, such as the reefs surrounding offshore islands in Papua New Guinea. The reefs are often located in shallow water that lies directly below overhead rainforest foliage.

Curious as to the navigational success of the fish, researchers led by Danielle Dixson, a James Cook University marine biologist, captured clownfish who had recently returned to their reef homes.

In a lab on the boat, the researchers inserted the fish into various streams of seawater containing different scents. One of the streams included sea anemone scent, while another contained leaves from the rainforest flora that overhangs the reefs. The result? The clownfish swam straight for those two scents, while largely ignoring others.

Dixson explained, “No one ever predicted that clownfish would be attracted to the scent of leaves. I just figured they might like beach water. I saw the islands had heavy vegetation, and I said, ‘Let’s give it a shot.’”

Even aquarium-born clownfish, who were also tested, were strongly attracted to the leaf and anemone scents. This indicates that the preference is “built into” clownfish rather than being acquired after birth, and the clownfish are then capable of smelling and tracking down the scents from afar.

Dixson noted that, in the context of conservation, the study may mean humans must protect more than just the reefs themselves; the rainforest vegetation could be just as crucial in guiding clownfish back home.

The clownfish thus joins a long list of incredible creatures whom God equipped with “advanced migratory technology” to aid in their life cycle and navigation.