• Development and Reproduction
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• v.11 no.2
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• pp.105-109
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• 2007

This study examined temperature effect in egg development and hatching of longtooth grouper, Epinephelus bruneus. Fertilized embryos was not growth after morula stage at $15^{\circ}C$, at 18, 21, 24 and $27^{\circ}C$, the required time from fertilized embryos to hatching were 70 h. 30 min., 44 h. 10 min., 29 h. 10 min. and 24 h. 30 min., respectively. The hatching rates at $24^{\circ}C$ were higher than the other conditions and the hatching was not occurred at $15^{\circ}C$. These results suggest that the water temperature range of egg development and hatching was $18{\sim}27^{\circ}C$.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.6
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• pp.847-852
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• 2014

The aim of this study was to investigate the effects of stocking density and water temperature in the rearing of the longtooth grouper Epinephelus bruneus. Juvenile fish [mean body weight (BW)=$6.9{\pm}1.1g$] were raised for 6 weeks, in four density groups of 0.25, 0.5, 0.75, and 1 individuals/L. There were no significant differences in weight gain (WG) or specific growth rate (SGR) among the density groups; however, both WG and SGR tended to be higher in the low density group. After 6 weeks of rearing in temperature-controlled water ($23.6{\pm}0.8^{\circ}C$) and ambient temperature water ($19.6{\pm}1.8^{\circ}C$), there were no significant differences in WG or SGR values, but both tended to be higher in the temperature controlled water. The feed efficiency (FE) and daily feed intake (DFI) and WG values were also higher in the temperature-controlled water than in the ambient temperature water. WG values were lower at lower water temperatures. The same pattern was observed for SGR, FE, and FI, all of which exhibited lower values at lower temperatures. In particular, WG, SGR, and FE values all tended to decrease at the $16^{\circ}C$ water temperature. The effects of water temperature on 1-year fish (mean BW = $387.6{\pm}30.2g$) and 3-year fish (mean BW = $1,338.3{\pm}73.8g$) were similar to those of the juvenile fish (0-year fish).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.2
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• pp.195-200
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• 2013

This study investigated the effects of water temperature, photoperiod and population density on oxygen consumption (OC) in the longtooth grouper (Epinephelus bruneus). OC rate in the longtooth grouper at 15, 20, and $25^{\circ}C$ were $85.9{\pm}6.9$, $107.5{\pm}10.1$, and $164.0{\pm}19.2\;mg\;O_2\;kg^{-1}\;h^{-1}$, respectively, indicating a linear increase in OC with water temperature. Photoperiod was regulated in accordance with the light (09:00-21:00 h, L) and dark (21:00-09:00 h, D) phases of the diel cycle (12L/12D), with a water temperature of 15, 20, or $25^{\circ}C$. OC rates during the light and dark phases were $83.8{\pm}5.4$, $88.1{\pm}7.8\;mg\;O_2\;kg^{-1}\;h^{-1}$, respectively, at $15^{\circ}C$ and $111.2{\pm}12.3$ and $103.7{\pm}5.7\;mg\;O_2\;kg^{-1}\;h^{-1}$ at $20^{\circ}C$. No significant differences were observed between the light and dark phases (P > 0.05). at $25^{\circ}C$ the OC rates were $168.8{\pm}24.3$ and $159.2{\pm}11.4\;mg\;O_2\;kg^{-1}\;h^{-1}$ during the light and dark phases, respectively, indicating that OC is higher during daylight than nighttime. OC tates at 55.4, 88.4, 118.8, and 145.1 g $L^{-1}$ were $252.0{\pm}11.6$, $219.0{\pm}8.7$, $206.7{\pm}11.4$, and $208.8{\pm}11.4\;mg\;O_2\;kg^{-1}\;h^{-1}$, respectively, indicating a decrease in OC with increasing population density. However, no significant difference was observed between the values for 118.8 g $L^{-1}$ and 145.1 g $L^{-1}$ (P > 0.05).