Blue-green chromis appear to be kissing but are really fighting during a mating event on the reef

Snorkeling with kissing fish in the Solomon Islands

Fish that appear to be kissing are not doing so as a part of showing affection for each other; rather it is a demonstration of aggression and bid for dominance between two males. The reason? Females, of course. The combat of ‘kissing’ is merely two males that are bumping into each other in an attempt to force the other to retreat from the immediate nesting area (or potential nesting area). During times of the month when, for example, these male blue-green chromis (Chromis viridis) are preparing to attract females to their nests, males will often turn bright yellow and fight with other males to secure the best place on the reef on which to set up their nest. Nests are usually small crevices or depression on the substrate where the eggs are semi-protected but are still exposed to water movement so they can access oxygenated water. The parents hover nearby and will guard them against potential predators until they hatch several days after they have been fertilized. I happen to come across these two blue-green chromis, while snorkeling in the Solomon Islands, who were more focused on fighting than assessing whether my large presence was a threat or not. They let me get pretty close, and I wonder how they would have reacted if I were a hungry grouper?

Kissing fish are often two males that are fighting for dominance

‘Kissing’ fish…

Male blue-green chromis (Chromis viridis) displaying his yellow mating variation

Male blue-green chromis…