To establish efficient feeding schedules for seed production of hatchery-reared barfin flounder Verasper moseri, we examined ontogenetic shifts in diel feeding pattern and digestive tract morphology during the larval and early juvenile stages. Under culture conditions (lights on 08:00, off 18:00), the number of prey items in the digestive tract (individuals fish-1) showed a unimodal diel pattern, peaking at 17:00 19:00 during the initial feeding (9 days after hatching; DAH) and pelagic (15 DAH) stages, whereas it showed a bimodal pattern, with peaks at 11:00 12:00 and 17:00 19:00 during the pre-settlement (40 DAH) and settlement (62 DAH) stages. Daily food consumption increased markedly from 0.18 mg day-1 in the initial feeding stage to 14.59 mg day-1 in the pre-settlement stage and 17.56 mg day-1 in the settlement stage. The corresponding daily food consumption rate (% body wight) was 42%, 90%, and 42%, respectively. The digestive tract gradually acquired an adult-like morphology through the expansion of the foregut into a sac-like structure and differentiation of the pyloric caeca during the pre-settlement stage. These results indicate that feeding characteristics change in association with the development of feeding and digestive capacities, particularly immediately before the onset of eye migration. Continuous feeding throughout the light period during the rotifer-feeding (initial feeding and pelagic) stage and twice-daily feeding in the morning and evening during the Artemia-feeding (pre-settlement and settlement) stage are therefore recommended.
