With a repertoire of 4 distinct grunts and croaks, the Lusitanian toadfish is relatively garrulous by fish standards. However, little is known about the way the fishes' voice changes as they grow, and even less about the way their hearing develops with age. Raquel Vasconcelos and Friedrich Ladich decided to record toadfish calls and test the hearing of fish ranging from a few months up to 8 years old to see how their communication skills develop(). The team found that as the fish aged, their voices became deeper and louder. However,the youngest fish were almost always silent; only one grunted, and it was the largest of the youngsters. And when the pair tested the fishes' hearing, they realized that the adults had no problem hearing each other, but the young juveniles' hearing was too insensitive to hear the weak, high voices of youngsters of their own age. Vasconcelos and Ladich suspect that the youngsters do not communicate vocally until their voices are deep enough and loud enough for them to hear each other.
Vasconcelos, R. O. and Ladich, F. (
2008
). Development of vocalization, auditory sensitivity and acoustic communication in the Lusitanian toadfish Halobatrachus didactylus. J. Exp. Biol.
211
,502
-509.
