Comparative growth, feeding and reproduction of hatchery-reared and wild mandarin fish Siniperca chuatsi in a shallow Yangtze lake, China

S Ye,Z Li,J Liu,M Lin,T Zhang,RE Gozlan,W Li

doi:10.3354/aei00417

Abstract

Stocking hatchery-reared fish in natural shallow lakes is a common practice in Chinese fisheries. The success of these fisheries depends on the balance between the commercial value of the stock and the growth performance of stocked fish to rapidly reach commercial size. The mandarin fish Siniperca chuatsi has become a commercially important fishery in China. However, the performance of hatchery-reared mandarin fish (HMF) after release into natural environments and their interactions with wild mandarin fish (WMF) have received little attention. In this study, we compared the growth, feeding and reproduction of HMF with WMF in a shallow Yangtze lake. We found that 11 mo after release, the growth of HMF was significantly slower than that of WMF but rapidly caught up after 16-19 mo. This suggests that HMF may experience compensatory growth after 11 mo, which may be a result of a low reproductive investment compared to WMF. In addition, the trophic niche of HMF differed significantly from that of WMF, with a lower diversity of prey and a single dominant prey species. Furthermore, there was no significant diet overlap between HMF and WMF. Our findings demonstrated that the growth performance of HMF can equal or exceeded that of wild conspecifics, and that there was limited diet overlap with WMF, suggesting that the current stock enhancement programmes of releasing HMF can result in fish similar to that of WMF, with limited foraging competition.

Highlights

Stock enhancement is a common fisheries management tool used extensively in both freshwater and marine environments (Huusko & Vehanen 2011)
We compared the growth, feeding and wild counterparts due to their higher aggressiveness reproductive characteristics of hatchery-reared mandarin fish (HMF) and wild manand usually larger size compared to wild conspecifics darin fish (WMF) with similar genetic backgrounds when released into the wild
For HMF, the diets of the small-size group were dominated by Rhodeus sp., H. leucisculus, shrimps and P. parva, with average %IRI values of 34.28, 19.96, 14.75 and 14.08%, respectively

Summary

Introduction

Stock enhancement is a common fisheries management tool used extensively in both freshwater and marine environments (Huusko & Vehanen 2011). The practice consists of releasing hatchery-reared stocks to increase the abundance and yield of a fishery population (Lorenzen 2005, Li et al 2014a). Stocking hatchery-reared fish has been used for fisheries practice since the mid-nineteenth century. Stockin fitness of wild populations when the proportion of ing natural lakes with HMF contributes to immediate hatchery fish is very high (Kitada 2020). Resource enhancement and increased economic benstocking hatchery-reared fish has often been a sub- efits (Cui & Li 2005, Li et al 2014b). The ject of controversy; its effectiveness and side-effects performance of HMF that are released into natural on wild stocks being questioned (Lorenzen 2005, Jon- environments and their interaction with the wild sson & Jonsson 2006, Araki & Schmid 2010)

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Conclusion