Table 7. Means (± SE) of the sonic parameters of Oreochromis niloticus females, recorded in situation of territoriality (Nest) and of oral incubation (Eggs).

	n	Nest (N = 7 females)	n	Eggs (N = 4 females)	t-Test (p<0.05)
Sound length (ms)	314	320.7±101	141	264.8±84	***
Nb of pulses/sound	314	3.1±1	141	2.5±0.6	***
Pulse duration (ms)	963	105.1±23	348	107.3±21	ns
Frequency (HZ)	963	49.6±14	348	48.3±16	ns

^***p<0.001.