Here's why they do it:
* Parasite removal: Parrotfish, like many other fish, are susceptible to parasites. Mutual grooming helps them remove these parasites, keeping them healthy.
* Social bonding: This activity strengthens social bonds within the parrotfish community.
* Hygiene: It helps keep their scales clean and free of debris.
So, while it might look like a romantic kiss, it's actually a very practical and hygienic behavior.