The visual acuties of striped beakperch larvae and juveniles were calculated from the size of baits taken and the reaction distance of the fish at 1000-1100 lx and the apparent contrast of the target at 2.0-3.0. The visual acuities were 0.011 for larva of 5.5mmTL and 0.06 for juvenile of 18mmTL. The relationship between visual acuity (VA) and fish size (TL) for the larval and juvenile stages were expressed by the equations VA=0.020 exp (0.326TL) and VA=-0.059+0.041 ln TL, respectively. The visual acuity of the juveniles was estimated to reach that of the adults at 38mmTL.
The visible ranges for 1 and 3mm size targets at the larval stage were 4 and 12cm, respectively, while at the juvenile stage they were five times those at the larval stage.