Erik Reeve, Serge Herilala Ndriantsoa, Axel Strauß,
Roger-Daniel Randrianiaina, Tahiry Rasolonjatovo Hiobiarilanto, Frank Glaw,
Julian Glos & Miguel Vences (2011): Acoustic underwater signals with a
probable function during competitive feeding in a tadpole.
Naturwissenschaften 98 (2), 135-143.
Abstract: Acoustic communication is widespread among adult stages of
terrestrial animals and fish and has also been observed in insect larvae. We
report underwater acoustic communication in the larvae of a frog,
Gephyromantis azzurrae, from Isalo, a sandstone massif in western
Madagascar. According to our field data, these tadpoles live in streams and
prefer habitats characterized by comparatively low temperatures, shallow
water depth, and a relatively fast current. Feeding experiments indicated
that the tadpoles are carnivorous and macrophagous. They consumed insect
larvae and, to a lesser extent, small shrimps, and conspecific as well as
heterospecific tadpoles. Calls of these tadpoles consisted either of single
click notes or of irregular series of various clicks. Some complex calls
have a pulsed structure with three to nine indistinct energy pulses.
Production of the pulses coincided with rapid closure of the jaw sheaths and
often with an upward movement of the body. Calls were emitted while
attacking prey and occurred significantly more often when attacking
conspecifics. Tadpoles that had not been fed for some time emitted sounds
more frequently than those that had been regularly fed. The spectral
frequency of the calls differed in tadpole groups of different size and was
higher in groups of smaller tadpoles, suggesting that spectral frequency
carries some information about tadpole size which might be important during
competitive feeding to assess size and strength of competitors. This report
differs from those for the larvae of South American horned frogs,
Ceratophrys ornata. These are the only other tadpoles for which sound
production has reliably been reported but the calls of Ceratophrys tadpoles
occur mainly in a defensive context.
URL: http://www.springerlink.com/content/2887272m20646x37/
For reprints please contact M. Vences (email:
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Sonja
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