LAUSR

Abstract Climbing perch is a potamodromous fish that undertake lateral migration from the permanent water bodies to flooded areas during the rainy season and return to permanent water bodies at the end of flood. In hatcheries, fish are normally reared in barren environments, which have been reported to affect their phenotypic development compared with wild conspecifics. Although rarely used, long-term behavioural training protocols provide opportunities to shape complex learning skills of fish in laboratory investigations that incorporate cognitive, motor, and temporal functions to achieve desired goals. In the present investigation larvae of climbing perch were reared in four different spatial complexities and use of landmark in route learning at 6th month (sub Adult) of rearing were studied. Results show that increase in complexity of the water column enhances the spatial learning ability and use of visual cue of the fish. Highest learning ability and use of visual landmark in spatial orientation was noticed in fish reared in the middle complexity, compared to other rearing environments. The effect of providing spatial complexity in rearing environment of fish larvae reared in hatchery as a method for the enhancement of spatial processing skill, and as an aid to improve cognitive development is discussed.