| Affiliation: | 1. Southern Marine Science and Engineering Guangdong Laboratory, Zhanjiang, China State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory for Aquatic Economic Animals and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, Guangzhou, China;2. Guangdong Key Laboratory of Animal Conservation and Resource Utilization, Guangdong Public Laboratory of Wild Animal Conservation and Utilization, Guangdong Institute of Applied Biological Resources, Guangzhou, China;3. College of Life Sciences, Southwest Forestry University, Kunming, China;4. Marine Fisheries Development Center of Guangdong Province, Huizhou, China;5. State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory for Aquatic Economic Animals and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, Guangzhou, China;6. Southern Marine Science and Engineering Guangdong Laboratory, Zhanjiang, China |
| Abstract: | Sex change in teleost fishes is commonly regulated by social factors. In species that exhibit protogynous sex change, such as the orange-spotted grouper Epinephelus coioides, when the dominant males are removed from the social group, the most dominant female initiates sex change. The aim of this study was to determine the regulatory mechanisms of socially controlled sex change in E. coioides. We investigated the seasonal variation in social behaviours and sex change throughout the reproductive cycle of E. coioides, and defined the behaviour pattern of this fish during the establishment of a dominance hierarchy. The social behaviours and sex change in this fish were affected by season, and only occurred during the prebreeding season and breeding season. Therefore, a series of sensory isolation experiments was conducted during the breeding season to determine the role of physical, visual and olfactory cues in mediating socially controlled sex change. The results demonstrated that physical interactions between individuals in the social groups were crucial for the initiation and completion of sex change, whereas visual and olfactory cues alone were insufficient in stimulating sex change in dominant females. In addition, we propose that the steroid hormones 11-ketotestosterone and cortisol are involved in regulating the initiation of socially controlled sex change. |
