Young (11-15 days, 8-10 mm), larvae of Amblyglyphidodon curacao were identified by mitochondrial DNA. Their behaviour dispersal-relevant was studied in lab and sea at Lizard Island, Great Barrier Reef. Behaviour varied little with size. Critical speed was 27.5 ± 1.0 cm s^-1, and in situ speed was 13.6 ± 0.6 cm s^-1, and equalled mean current speed. Unfed larvae swam 52.0 ± 8.6 km at 8-10 cm s^-1, losing 25% wet weight. Modal depth was 7.5 m and 11.25 m at leeward and windward sites, respectively. Over 80% of 71 larvae observed swam directionally. Larvae avoided NW bearings, with an overall mean SE swimming direction. Larvae made smaller turns when swimming SE than in other directions, making it likely they would continue to swim SE. When swimming NW, 62% of turns were left, resulting in rapid change away from NW. Clearly, the larvae knew the direction in which they were swimming, and chose SE. The cues used for orientation are unclear. Near Lizard Island, A. curacao larvae swam into the mean current at speeds equivalent to it, could do this for many hours, and chose different depths in different locations. These behaviours will strongly influence dispersal and are similar to behaviour of other settlement-stage pomacentrids that are older and larger.