Growth of over-wintered and pre-seasonally produced post-larvae of penaeus semisulcatus in the subtropics [Yarı-tropik koşullarda kışlatılmış ve mevsim-öncesinde üretilmiş olan penaeus semisulcatus postlarvalarında büyüme]

Growth performance of Penaeus semisulcatus under semi-intensive and intensive systems in pond/tank culture conditions with pre-seasonally or over-wintered animals was studied in sub-tropical climate conditions of Turkey. In Pond A, the pre-seasonally produced post-larvae (PL) grew linearly from 0.2 g to 22.6 g in 140 days (Y = 0.19 X- 2.69; R2 = 0.97) with DGR (daily growth rate) of 0.06 g day-1. In Pond B, the over-wintered juveniles grew from 3.8 g to 30.5 g with DGR of 0.41 g during the first 30 days (weight gain of 14.42 g) and 0.13 g between 30 and 140 days (weight gain of 14.32 g). Regression equation for growth was calculated to be Y = 9.62 Log (X) + 4.51 (R2 = 0.99). Compensatory growth due to starvation or over-winter fasting has, for the first time, been demonstrated in this penaeid shrimp species in the present study. Food deprivation during the winter months resulted in growth compensation after re-feeding under appropriate culture conditions. During the compensatory growth period (first month after re-feeding), the shrimps gained an average weight of 2.87 g week-1, but after this period, growth rate declined to 0.91 g week-1 (over three-fold less) for the rest of the growth period (between 2nd and 5th months). This preliminary finding is a promising area on which studies should be focused on, as fasting and re-feeding strategy at low temperature can provide a chance to increase marketable size of shrimps or to even produce two crops per year in the sub-tropics. The shrimps (0.2 g) reached to 13.7 g at 30 PL per m2 (DGR 0.10 g), 6.44-7.37 g (DGR 0.05 g) at 40-50 PL per m2 in 140 days. The estimated yields were 880-1,150 kg ha-1 in semi-intensive ponds and 1,597-2,673 kg ha-1 in intensive ponds. The shrimps grown in concrete Tanks displayed even poorer growth performance resulting in only 879 kg and 793 kg ha-1 of yield. © Published by Central Fisheries Research Institute (CFRI) Trabzon, Turkey