Toadfish call could throw light on ability to talk

The odd mating call of the homely toadfish might one day tell scientists how the ability to talk developed.

The toadfish, which has a wide mouth and red eyes and lives in the Gulf of Mexico along the US coast, emits sort of a hum when in search of sex.

The communication turns out to be useful not only for the fish but for science. Exploring how its nervous system produces sounds is allowing scientists to trace the earliest developments of vocalisation in other animals, including people.

Many animals communicate vocally - birds chirp, frogs thrum, whales whistle - and comparing the nerve networks in a variety of vertebrates suggests that making sounds originated in ancient fishes, researchers report in on Friday's edition of the journal Science.

The sounds of sea mammals such as whales and dolphins are well known, but most people do not realise that fish also make sounds, lead researcher Andrew H. Bass of Cornell University said in a telephone interview. He's a professor of neurobiology and behaviour.

Ancient

"I'm not saying fish have a language or are using higher powers of the brain," he added quickly. "But some of the networks of neurons, nerve cells in the brain, are very ancient."

The whole nervous system basis that led to speech originated in fish hundreds of millions of years ago, he said. He studied the hindbrain in the larvae of midshipmanfish and toadfish, which grow up to produce more than one type of sound.

"It's not as complex as what you hear mammals and birds doing; it's the simplest type of communication ... but the parts of the nervous system that generate sounds are easiest to study in these fish," Bass said.

The locations of the vocal nerves described in the study are consistent with the organisation of the vocal systems in frogs, birds and mammals, supporting the idea of a common early development, Daniel Margoliash and Melina E. Hale of the University of Chicago comments in a perspective on Bass's study.