REDUCTION OF MORPHOLOGICAL ABNORMALITIES IN BROWN SOLE BY LARVAL REARING WITH HIGHER TEMPERATURE AND EARLY FEEDING OF ARTEMIA-NAUPLII

Brown sole Pleuronectes herzensteini were reared experimentally to the juvenile stage to determine the influence of rearing temperature and the timing of feeding Artemia Artemia salina nauplii on the occurrence of morphological abnormalities. In one series of experiments, sole la rvae were reared at different temperatures (6-24 degrees C) with the s ame feeding schedules. Bearing temperatures higher than 18 degrees C r educed the appearance of morphological abnormalities. In the second se ries of experiments, the initial feeding of addition of Artemia naupli i was varied among experimental groups at constant temperature (15 deg rees C). The first group to receive Artemia nauplii were at the 4.5-8. 0 mm TL of sole larvae and the last group did not receive them until m etamorphosis. Early feeding of Artemia nauplii reduced morphological a bnormalities. Subsequently, mass production techniques were modified t o determine if a combination of early feeding of Artemia nauplii to so le larvae (5.5 mmTL) and high rearing temperature (18 degrees C) could reduce morphological abnormalities in mass production tanks (20-50 m( 3)). These modifications resulted in the highest percentage (56-80%) o f normal fish observed during the eleven years of mass seed production of brown sole.