Effects of dry pellets containing astaxanthin and squid meal on the spawning performance of striped jack Pseudocaranx dentex
This study was conducted to investigate the effect of
squid meal and astaxanthin in dry pellets on the spawning performance of
striped jack. Two groups of 8-year-old fish with an average bodyweight of
3.5 ± 0.4 kg were used. The control group was fed a raw fish mix (RF) and
the experimental group was fed steam dry pellets (as-DP) containing 10
p.p.m. astaxanthin and squid meal, the latter replacing half the fish meal.
Each group was fed once a day, three times a week in floating net cages for
a period of 5 months. Seven females and seven males were selected from each
group and transferred to 65 m3 indoor concrete tanks for
spawning, where they were kept at optimum spawning conditions (22°C) for 1
month. The average body weights of selected fish were 3.8 ± 0.5 kg and 3.8
± 0.6 kg for the RF and as-DP groups, respectively. Both groups spawned a
total of 18 times and the mean total egg production and egg quality,
measured in terms of buoyancy, fertilization and hatching rates, showed no
significant differences (P > 0.05) between groups. Total larval
production was 679.9 × 103 and 678.1 × 103
larvae/kg-female for the RF and as-DP groups, respectively. These results
show that the combination of astaxanthin and squid meal in dry pellets for
striped jack broodstock improved the overall spawning performance to a level
similar to that of fish fed on RF.
(Laboratory of Fish Nutrition, Department of Aquatic Biosciences, Tokyo University of Fisheries, Konan, Minato, Tokyo 108-8477, Japan, Tel: 81-3-5463-0546. Fax: 81-3-5463-0553. e-mail of T. Watanabe: watana@tokyo-u-fish.ac.jp)