Ocean pollution is unfortunately becoming more commonplace, raising concerns over the effect of chemicals that are leaching into the water. In a new study, researchers have discovered how these chemicals can affect the reproduction in common anemonefish Amphiprion ocellaris.

The anemonefish is a gender-bending marvel. It starts out as a male, but can switch to female when circumstances allow, for example, when the only female present dies or disappears. In a new study, researchers found that the male-to-female sex-change occurs first in the fish’s brain and only later involves the gonads – sometimes after a delay of months or years.