Effect of photoperiod on growth and gonadal development of juvenile Topmouth Gudgeon Pseudorasbora parva
2014
Zhu, Dongmei | Yang, Kun | Gul, Yasmeen | Song, Wen | Zhang, Xinhui | Wang, Weimin
In this study, we investigated the effect of photoperiod on growth and gonadal development of juvenile topmouth gudgeon, Pseudorasbora parva. Seven different photoperiods (light:dark, L:D) were tested: 0L:24D, 4L:20D, 8L:16D, 12L:12D, 16L:8D, 20L:4D and 24L:0D, from November to January. Throughout the study, light intensity was kept at 400 lx on the water surface, and the fish were fed a commercial diet twice a day. Weight gain, feed intake, specific growth rate, and feed conversion efficiency were significantly higher under the constant–long day photoperiods (24L:0D, 20L:4D and 16L:8D) than those under the short–no day photoperiods (12L:12D, 8L:16D, 4L:20D, 0L:24D) (p < 0.05). The highest mean female gonadosomatic index (GSI) and mean oocyte size were observed under 24L:0D followed by 20L:4D and 16L:8D photoperiods, and these parameters were significantly higher than those of fish cultured under the short–no day photoperiod regimes (p < 0.05). Proportion of females with GSI > 9 % were 50.00 %, 46.67 %, 48.48 %, in 24L:0D, 20L:4D and 16L:8D, respectively. These results demonstrate that the growth of juvenile P. parva can be stimulated significantly by constant–long photoperiods and that these photoperiods can advance sexual maturity of females by approximately 2 months.
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