Investigation on feeding behaviour of Yellowfin seabream larvae, Acanthopagrus latus, fed on live food and microencapsulated diet

Feeding behavior of yellowfin seabream larvae during the first two weeks of larval life was studied by feeding larvae on different ratios of live food and microencapsulated diet (MED). Food consumption rate increased progressively with increasing larval weight. The results from visual observation of the larval guts under a light microscope indicated that yellowfin seabream larvae were able to ingest and digest MED from the onset of exogenous feeding.Comparing the average number of rotifers and MED ingested by larvae in treatments including either only live food or MED did not show any significant differences (P>0.05). In addition, the gut contents examination from the larvae fed simultaneously on both rotifer and MED, revealed that the larvae's tendency towards live food and/or MED was a function of live food density in the rearing tanks. The larvae preferentially ingest live food even when these are present at a very low concentration in comparison to MED. The mouth diameter of larvae has a strong influence on the amount of ingested rotifers and MED.There was a significant positive correlation between larvae growth and the average number of both live food and MED ingested by larvae in this trial (P<0.01). Although larvae survival rate had a positive correlation with the number of rotifers ingested, the amount of MEDin the larvae's gut did not show effect on larvae survival rate (P>0.05).