Research

Publications
Title: Differences in anti-predator behavior and survival rate between hatchery-reared and wild grass carp (Ctenopharyngodon idellus)
First author: Tang, Lijun; Jacquin, Lisa; Lek, Sovan; Liu, Huanzhang; Li, Zhongjie; Liu, Jiashou; Zhang, Tanglin
Journal: ANNALES DE LIMNOLOGIE-INTERNATIONAL JOURNAL OF LIMNOLOGY
Years: 2017
Volume / issue: 53 /
DOI: 10.1051/limn/2017020
Abstract: Grass carp Ctenopharyngodon idellus, is the primary freshwater species produced in China. Because natural populations have shrunk in the wild, restocking programs using hatchery-reared fish have emerged. Artificial rearing could affect fish anti-predator behavior, thus decreasing their survival in the wild. The impact of artificial rearing on C. idellus's behavior remains unknown because empirical studies are scarce. In this study, wecompared anti-predatorbehaviorandsurvival rate between hatchery-rearedandwild C. idellus. Both hatchery-reared and wild C. idellus displayed clear anti-predator behavior when exposed to visual and odor cues of a predator. However, hatchery-reared C. idellus showed significantly lower aggregation index (reflecting shoaling behavior), inspection rate and spent less time in risky area compared to their wild counterparts. When directly exposed to predators, more hatchery-reared C. idellus were predated. This raises concerns about the efficiency of restocking programs and highlights the need to adjust artificial rearing and stocking conditions of C. idellus to produce fish that are better adapted to natural conditions.