Use of response surface methodology to study the combined effects of temperature and salinity on hatching and deformity of the hybrid grouper,Epinephelus fuscoguttatus(♀) × Epinephelus polyphekadion(♂)

Abstract

This study seeks to identify the optimal combination of temperature and salinity for the embryo development of the hybrid groupers, Epinephelus fuscoguttatus (♀) × Epinephelus polyphekadion (♂), using the central composite design and response surface methodology. Results have shown that the low hatching rates of fertilized eggs and high deformity rates of larvae were the result of lower or higher temperature/salinity levels. The linear effects of temperature and salinity were significant in both hatching rates and deformity rates (p < .01). Similar results were observed in the quadratic effects of temperature and salinity (p < .01). Effects of temperature were positively related to salinity effects (p < .05). Salinity effects were more remarkable than temperature on hatching rates, but not the same on deformity rates. Model equations were established for temperature and salinity effects on hatching rates and deformity rates. A high coefficient of determination (R2 > .97) was found for the adequacy and predictive capability of model equations, indicating that these models can be applied to prediction. The optimal combination of temperature and salinity was 27.58°C/30.94, which was derived from the statistical optimization approach. In this condition, the hatching rate was the highest at 85.73%, and the deformity rate was the lowest at 5.96%, with a high desirability function of 0.957. The results of this study can be applied to improve hatching and decrease deformity in future cultures of hybrid groupers.

The first successful land-based larviculture of narrow-barred Spanish mackerel (Scomberomorus commerson) and the assessment of optimal water conditions for larval survival using response surface methodology

“…Despite this limitation, the RSM approach enabled the analysis and modeling of the data. The results from the response surface model revealed a signi cant in uence of temperature and salinity on the survival of S. commerson larvae, with notable quadratic effects suggesting the presence of an optimal combination of temperature and salinity for larval survival (Huang et al 2018).…”

“…The S. commerson and S. niphonius exhibit piscivorous behavior (Shoji et al 1997(Shoji et al , 2002aSugino et al 2005), characterized by a larger mouth size (664.71 ± 16.33 µm) in comparison to typical marine carnivorous aquaculture sh species, such as the kelp grouper (Epinephelus moara, 307.18 ± 9. 29 In this study, the feeding strategies for two batches of larviculture were identical. In the initial feeding phase, apart from being fed copepods, the larval four-nger thread n were also provided.…”

“…Typically, in efforts to determine the optimal temperature and salinity conditions for speci c marine sh, researchers expose fertilized eggs to different temperature and salinity levels. This approach allows for the evaluation of optimal conditions for hatchability and larval survival (Huang et al 2018; Chiu and Leu 2021; Groover et al 2021). Response surface methodology (RSM) has been effectively utilized for process optimization and has also found application in the investigation of temperature and salinity combinations during the early development of aquatic organisms (Wang et al 2012;Huang et al 2018).…”

“…This approach allows for the evaluation of optimal conditions for hatchability and larval survival (Huang et al 2018; Chiu and Leu 2021; Groover et al 2021). Response surface methodology (RSM) has been effectively utilized for process optimization and has also found application in the investigation of temperature and salinity combinations during the early development of aquatic organisms (Wang et al 2012;Huang et al 2018). Among its merits, RSM enables the design of a comprehensive model to describe system characteristics while minimizing the required number of experiments, thus identifying optimal temperature and salinity conditions (Huang et al 2018).…”

“…The levels were coded as -α, -1, 0, + 1 and + α, respectively, with α representing the axial point. The design consisted of 13 runs, including 4 factorial points, 4 axial points, and 5 center points (Huang et al 2018). The objective was to investigate the optimal larval survival under various temperature and salinity conditions.…”