Eligible Lusitanian toadfish females are always looking out for the best fathers as toadfish dads are actively engaged in their youngsters' future. Standing guard over their nests for 30 days, they protect their eggs and fan them to keep them ventilated. During their long vigil, the males never leave the nest; so prospective fathers have to be fit and toadfish mums want to pick the strongest partners to give their young the best start in life. Clara Amorim and her colleagues from Lisbon, Portugal, wondered how toadfish males advertise their fitness, so they focused on the fish's mating call (p. 2997). Recording males' mating chirrups and checking their physical condition, the team found that the fittest males called more frequently and longer than their weaker counterparts. The fittest males also had larger sonic muscles and gonads and produced shorter chirrup pulses. The team suspects that males that call more often and can contract their sonic muscle fast to generate short chirrup pulses are not just bragging: they're simply being honest about being the best.

Amorim
M. C. P.
,
Simões
J. M.
,
Mendonça
N.
,
Bandarra
N. M.
,
Almada
V. C.
,
Fonseca
P. J.
(
2010
).
Lusitanian toadfish song reflects male quality
.
J. Exp. Biol.
213
,
2997
-
3004
.