R. Vassallo-agius et al., Effects of dry pellets containing astaxanthin and squid meal on the spawning performance of striped jack Pseudocaranx dentex, FISHERIES S, 67(4), 2001, pp. 667-674
This study was conducted to investigate the effect of squid meal and astaxa
nthin in dry pellets on the spawning performance of striped jack. Two group
s 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 squi
d 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. Sev
en females and seven males were selected from each group and transferred to
65 m(3) indoor concrete tanks for spawning, where they were kept at optimu
m spawning conditions (22 degreesC) for 1 month. The average bodyweights 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, fertil
ization and hatching rates, showed no significant differences (P>0.05) betw
een groups. Total larval production was 679.9 x 10(3) and 678.1 x 10(3) lar
vae/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 stri
ped jack broodstock improved the overall spawning performance to a level si
milar to that of fish fed on RF.