A. Bisazza et al., Heritability of lateralization in fish: concordance of right-left asymmetry between parents and offspring, NEUROPSYCHO, 38(7), 2000, pp. 907-912
The poeciliid fish Girardinus falcatus shows a consistent population bias t
o detour a vertical-bar barrier preferentially leftwise when approaching a
dummy predator to inspect it; the asymmetry seems to be due to a preferenti
al use of the lateral field of the right eye during fixation of biologicall
y relevant stimuli such as a predator. In order to unravel the origins of t
his lateral bias, we took advantage of the individual variability present i
n the natural population to perform artificial selection experiments. Males
and females that scored similarly at the detour test were mated together a
nd their progeny were tested in the same task. Results showed that there wa
s a striking similarity in the strength and in the direction of the asymmet
ries between parents and offspring. Correlation was highly significant and
the estimate of heritability was greater than 0.5. This represents the firs
t demonstration of heritability of the direction of a behavioural asymmetry
outside the primate order. The finding paves the way to the use of a novel
and suitable animal model for the neuro-genetics of lateralization and to
the possible identification of homologous and/or analogous genes underlying
brain asymmetry among vertebrates. (C) 2000 Elsevier Science Ltd. All righ
ts reserved.