The nauplii of Balanus amphitrite (Cirripedia: Thoracica) were cultured on a daily diet of Chaetoceros gracilis at different concentrations. Both young (zero-day old) and aged (six-day old) cyprids were subject to attachment assays, followed by studies of juvenile growth and survival for two weeks under laboratory conditions. The TAG/DNA ratio of cyprid increased in the following order of food concentrations: 106>105>104 cells ml−1. More than 70% of cyprids metamorphosed in the presence of conspecific settlement factor, irrespective of their TAG/DNA ratio. The juvenile growth and survival in young cyprids surpassed that of the aged cyprids. The TAG/DNA ratio had no significant effect on juvenile growth and survival in both young and aged cyprids. The negative effect of delayed metamorphosis on juvenile growth and survival appeared to be independent of the TAG/DNA ratio.