The same variables of the cranial and caudal sacs would be observed in order to determine if the sounds being produced where indeed coming from these organs or not. It may be that these two organs are either the source of the sound or are in someway related to the sound that these researchers heard during the tank experiment coming from the swimbladder. Did the newspaper article describe the research article correctly? Explain.

The newspaper article "Hearing the Repertoire of a Very Fearsome Fish" by Bhanoo (2011) did a good job in describing the research article correctly. It described how the researchers used piranhas to study and how they used a hydrophone to record underwater sounds coming from the piranhas. It described how the sounds made were recorded during fighting, charging and frontal display. The author explained how it was previously believed that piranhas produced...

The article also discussed the fact that the researchers discovered that piranhas make the barking and drumming sounds by rapidly contracting a muscle that is attached to the swim bladder.
Works Cited

Bhanoo, S.N. 2011. "Hearing the Repertoire of a Very Fearsome Fish." Web. Available at:

http://www.nytimes.com/2011/10/18/science/18piranha.html?_r=1&scp=1&sq=repert oire%20of%20fish&st=cse

Millot, S., Vandewalle, P. & Parmentier, E. 2011. "Sound production in red-bellied piranhas

(Pygocentrus nattereri, Kner): an acoustical, behavioural and morphofunctional study." The Journal of Experimental Biology, 214, 3613-3618.