Suitable light intensity during the ontogenetic development of white trevally, Pseudocaranx dentex (Bloch and Schneider, 1801), larvae

Abstract

Three experiments were conducted to elucidate the most suitable rearing light intensity during the ontogenetic changes in white trevally (Pseudocaranx dentex) larvae. In Experiment 1, larvae were reared under 1000, 3000 or 9000 lx. At 10 days post hatching (dph), larval growth was significantly higher in the 1000 lx treatment than in the other treatments. In Experiment 2, larvae were reared under 30, 100, 300, 1000, 3000, and 9000 lx, and 300 lx was revealed to be the most suitable light intensity for larval growth and survival until 10 dph. However, light intensities higher than 1000 lx may promote larval growth after 10 dph when the larval retina has developed prior to the metamorphic stage. In Experiment 3, larvae were exposed to increasing light intensities (i.e. from 300 lx to 1000, 3000 and 9000 lx) from 10 to 18 dph. Our results indicated that the most suitable rearing light intensity was 300 lx during the first week of development and at the commencement of feeding, and between 1000 and 3000 lx when the larvae approached the metamorphic stage. The rearing light intensity should, therefore, be adapted throughout the ontogenetic development of white trevally to promote larval growth and production efficiency.