CICHLIDAE

The Cichlidae family comprises approximately 1300 species, some of which produce sounds in specific behavioural situations. Within this family, Tilapias (genera Oreochromis, Sarotherodon and Tilapia) are fish whose behaviour has already been the object of much research, but without ever taking into account the audio component, the omission of which can strongly skew interpretations.

The purpose of this research is to investigate two principal aspects of sound production in Oreochromis niloticus:

  • To define the acoustic repertoire of the Nile Tilapia as well as the behaviours associated to each sound.
  • To determine the sound production mechanism and its development.

Certain sounds produced by the Nile Tilapia, Oreochromis niloticus (Linnaeus 1758) have been recorded, analyzed and characterized for the first time in our laboratory. These sounds or trains of pulses (Fig. 1.1) are characterized by a significant pulse duration (± 150 ms) (Fig. 1.2) and a low primary frequency (<100Hz) (Fig. 2). These characteristics are not common in the sounds of other Cichlid species.

 

oscilloFig. 1.1 Oscillogram showing four trains of pulses and the number of pulses which composes them (in yellow), in O. niloticus.

 

oscillo2Fig. 1.2 Oscillogram showing a train of pulses composed of 2 pulses (delimited by the yellow box) in O. niloticus.

 

spectro

 

Fig. 2 Spectrogram of one pulse, in O. niloticus