Daniel, Koffinas and Hughes [1] (hereafter DKH) reported that the mating preferences
of female Trinidadian guppy (a tropical fish) are subject to habituation,
a behavioural phenomenon reflecting a widespread form of ancestral learning
in the animal kingdom [2,3]. The authors found that when a female was repeatedly
exposed to a male with a given colour pattern, the female mating interest
for males with a similar pattern decreased as a function of the number of
exposures. DKH also showed that this response decrement presents several features
of habituation, such as stimulus specificity (the mating response recovers
for a male with a different colour pattern), spontaneous recovery (the response
recovers if the habituated male is temporarily removed) and dishabituation
(responsiveness to the habituated male recovers after exposure to a novel male).
While the study is certainly of interest, because it shows that habituation can
affect biologically significant stimuli, we regretfully have to note that DKH have
completely overlooked two areas of research whose results are highly relevant
for the question addressed in their study and that can help to understand the
reported findings.
