Fish 'grunt, growl and pop' at each other!

Wellington, July 7 (ANI): Fish 'grunt, growl and pop' at each other, says a Kiwi marine scientist.

Shahriman Ghazali, of the University of Auckland, is currently making underwater recordings at Leigh Marine Reserve to find out which fish talk and why.

"All fish can hear, but not all can make sound - pops and other sounds made by vibrating their swim bladder, a muscle they can contract," The New Zealand Herald quoted him, as saying.

Fish are said to talk to each other for numerous reasons, such as attracting mates and scaring predators.

Ghazali began his study by placing fish in tanks, and left them there for several weeks to allow them to acclimatise, after which he started making underwater recordings.

When the fish made noises, he tried to understand the context of this communication.

He said: "This is the next step. We are 99 per cent sure they are fish sounds, now we want to find out what the sounds mean."

Gurnard were found to have a wide vocal repertoire, and maintained a constant chatter.

Ghazali also found that big eye fish and not crayfish made "popping" sounds.

He said: "Some species of crayfish elsewhere do make a sound, which is like strumming a guitar. So I caught a few and listened but didn't get any sound."

Some fish spoke only occasionally. Ghazali noted that cod were mostly silent, but very noisy while spawning.

He explained: "The hypothesis is that they are using sound as a synchronisation so that the male and female release their eggs at the same time for fertilisation."

"Outside spawning season, you wouldn't hear a sound from them."

Ghazali believes predators could find prey by intercepting fish talk.

And species found mostly around reefs, such as the demsel fish, attempted to scare off threatening fish, or even divers, by making sounds.

Ghazali's paper on fish vocalisation will soon be presented at the New Zealand Marine Sciences Society conference in Wellington. (ANI)