It's been proven that fish can talk - that's according to new research by scientists at the University of Auckland.
Research shows some fish are communicating in the same way as mammals, using contact calls to stick together.
Established from the University’s Institute of Marine Science, the research was led by Master’s student Lucy van Oosterom and included Dr Craig Radford and Professors John Montgomery and Andrew Jeffs.
The team used Bigeyes (Pempheris adspersa) fish as their case study, a species commonly found along New Zealand’s north-east coast.
Ms van Oosterom says the Bigeyes make a popping sound both day and night.
“What we think is happening is that the Bigeyes are using their vocalisation as a means to keep within a group or keep in touch with each other when they're moving beyond visual cues,” she said.
Scientists say they’re already aware fish use messages for mating purposes or to defend territory, but this research is the first to prove they use contact calls to keep safe like mammals.
“Schooling in fish or shoaling which is the loose behaviour is pretty important for foraging success.
“So if one fish finds food the others have more of a chance of finding food and also to keep safe from predators – in a big group you're less likely to be picked off,” Ms van Oosterom says.
“They've got special muscles called sonic muscles which they use to vibrate the swim bladder which is like an air-filled sack inside their body and that vibration then comes out as this little popping sound that you can hear.
Even though they have a different way of communicating than we do, Msvan Oosterom says it’s an important step in our understanding of evolutionary behaviour.
"Fish evolved really early on in vertebrates and this is the first evidence of fish using contact calls so this behaviour could have evolved really early on as well."
Meaning we may not be so different from our fishy friends after all.