# General Topics > General Discussion & News > Press / News Items > Amphibian News Feeds >  Frog tadpoles 'scream' underwater

## Frog News

*(This article is about Pacman Frogs)

BBC News (London, UK) April 13th, 2010 05:57 AM: Frog tadpoles 'scream' underwater*

Tadpoles produce a sharp distress call when attacked, the first evidence that any underwater larva uses sound to communicate.
They only make the noise, described as a brief, clear metallic sound  made up of a series of notes, when in distress. 
It is the first  time any vertebrate larva has been found to use sound to communicate  underwater. 
The discovery that frog tadpoles can make sounds also  raises the possibility that a host of aquatic larvae communicate in a  similar way. 
The distress calls are made by tadpoles  of the horned frog _Ceratophrys ornata_ which lives in Argentina,  Uruguay and Brazil, researchers report in the journal Acta Zoologica.
Scientist Dr Guillermo Natale of the National University of La Plata  in Buenos Aires, Argentina, and his colleagues, were studying the mating  calls of adult frogs. 
Many adult amphibians use loud sounds such  as croaks to advertise their presence, and often to attract sexual  partners. 
Until now though, researchers did not realise that  amphibian larva might also produce sounds underwater. 
That  changed when Dr Natale caught a horned frog tadpole in a pond using a  hand-held net.
"We heard a brief, clear and very audible metallic-like sound," he  told the BBC. 
_C. ornata_ tadpoles are difficult to find in  the wild, so the researchers caught a wild pair of breeding adults, and  began a programme to rear the young amphibians in captivity. This  enabled the scientists to better study the noise they had heard in the  field. 
The team discovered that _C. ornata_ tadpoles are  naturally aggressive and carnivorous, often eating the tadpoles of other  frog species that they encounter. 
However, "much to our  astonishment, they do not eat each other," says Dr Natale, who is also  an assistant researcher Argentinean Research Council (Conicet). That may  be because of the "screams" emitted by the tadpoles. 
The  researchers found that when _C. ornata_ tadpoles come into contact  with, or are prodded by, an external object such as a metal spatula,  they let out a brief, metallic sound consisting of a short series of  higher frequency pulses.
Each "scream" lasts for just 0.05ms. 
Producing distress calls  is likely to help prevent the tadpoles cannibalising each other. 
*Continued in Full Article*

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## Maple

Net  :Big Applause:

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