Precise endogenous control of involvement of right and left visual structures in assessment by zebrafish.

Birds and fish use monocular viewing to bring to bear appropriate lateralised specialisations. In larval zebrafish, persistent left eye (LE) viewing of their own reflection is interrupted by a series of brief 'events', in which the right eye has equal use. These recur with precise 160 s periodicity, with the first beginning after 40s, and allow right and left mechanisms to assess the reflection.

fsi zebrafish show concordant reversal of laterality of viscera, neuroanatomy, and a subset of behavioral responses.

Asymmetries in CNS neuroanatomy are assumed to underlie the widespread cognitive and behavioral asymmetries in vertebrates. Studies in humans have shown that the laterality of some cognitive asymmetries is independent of the laterality of the viscera; discrete mechanisms may therefore regulate visceral and neural lateralization. However, through analysis of visceral, neuroanatomical, and behavioral asymmetries in the frequent-situs-inversus (fsi) line of zebrafish, we show that the principal left-right body asymmetries are coupled to certain brain asymmetries and lateralized behaviors.

Early asymmetries in the behaviour of zebrafish larvae.

Zebrafish (Brachydanio rerio) larvae (8 days) were tested singly in a swimway made up of six compartments. The larva emerged into each compartment in turn, and its response to visual features (e.g.