Scientists in Argentina have recorded what they say are high-pitched screams by tadpoles in distress. It's the first time any kind of underwater larvae have been identified as capable of making a sound. The discovery may have significant implications for future amphibian research.
At the University of La Plata, Argentina, researchers have discovered that tadpoles of the species commonly known as Pacman frogs, emit high-pitch screams while underwater.
Video recordings by the scientists show that the tadpoles let off a sharp, metallic sound when they run into other tadpoles, or feel they are under attack.
Frogs are well known for croaking in mating rituals, but globally, tadpoles have never been known to make sounds.
Researcher at CONICET and investigator at the University’s Environmental Studies Center, is Guillermo Natale.
[Guillermo Natale, Lead Scientist]: (Male, Spanish)
"Everyone has heard the sounds [frogs make] in the atmosphere, but nobody thought to put a microphone underwater to see what the tadpoles did.”
Pacman frogs, which are popular household pets in many countries, are also ferocious carnivores.
The frogs eat birds, insects, small mammals and other frogs almost as big as themselves.
Research assistant, Raul Herrera says they believe the screams from the tadpoles are defensive sounds used to tell their siblings that they are members of the same species.
[Raul Herrera, Research Assistant]: (Male, Spanish)
"When the tadpoles are in the same tank as other tadpoles they hunt the tadpoles of other species, but not tadpoles that are of the same species.”
The Argentine scientists carried out the study after noticing the tadpoles screamed when taken out of the water.
Next, the scientists want to analyze other similar species to see if they too shriek when under threat.