DISCUSSION
The differences in the natural distributional patterns of
prawns and shrimps follow our expectations from the
ecology of the two species, and are matched by the
laboratory-based choice experiments. Unlike prawns,
which readily associated with a group of conspecifics,
shrimps only showed a weak tendency towards active
shoaling behaviour in our experiment. Shrimps also spent
less time shoaling (i.e. in either of the end-zones) than