Waypoint Spring 2015



Reef danger likely triggers baby fishes’ first 'words'

Reef danger likely triggers baby fishes’ first 'words'

Facial markings of a young damselfish may communicate messages of danger. Photo: AIMS

A surprising find has revealed that baby fish who communicate using ultraviolet facial patterns don’t automatically develop the patterns as expected.

AIMS researcher Dr Martial Depczynski, along with scientists from the University of Western Australia and The University of Queensland, were testing when and how baby coral reef fish first start ‘talking’ to each other.

But their fish didn’t develop the ultraviolet (UV) face markings at all under laboratory conditions: even with different conditions for food and density.

“We realised there must be something about their natural reef environment which triggers the need to rapidly develop this communication channel,” says Dr Depczynski.

Developing the UV face markings that are invisible to their predators, then, is not actually ‘hard-wired’ for the young fish.

“These baby fish are under tremendous pressure from predators so their first ‘words’ are most likely going to be important ones: ones that enhance survival,” Dr Depczynski says.

The lack of danger in the lab environment is the most likely reason the baby fish didn’t develop the markings, he says. “And it’s probably why they need to develop them so quickly on the reef.”

The team was pleased when the novel findings were recognised and published in Scientific Reports, a high impact journal. The project was funded by an Australian Research Council Grant.

Dr Depczynski already has the next project in mind: “We are just touching the tip of the iceberg with this research. In the next study, we’d like to see if exposing fish to predators in the lab is enough to trigger the markings."

“UV signalling may convey a whole range of different information we don’t know about. Understanding what and how much animals are able to communicate to each other is one of science’s most intriguing mysteries.”