Age, growth, mortality and recruitment of thin sharpbelly Toxabramis swinhonis Günther, 1873 in three shallow lakes along the middle and lower reaches of the Yangtze River basin, China

Xianghong Dong; Tao Xiang; Tao Ju; Ruojing Li; Shaowen Ye; Sovan Lek; Jiashou Liu; Gaël Grenouillet

doi:10.7717/peerj.6772

Age, growth, mortality and recruitment of thin sharpbelly Toxabramis swinhonis Günther, 1873 in three shallow lakes along the middle and lower reaches of the Yangtze River basin, China

PeerJ. 2019 Apr 12:7:e6772. doi: 10.7717/peerj.6772. eCollection 2019.

Authors

Xianghong Dong^{1

2

3}, Tao Xiang^{1

2}, Tao Ju⁴, Ruojing Li^{1

2}, Shaowen Ye¹, Sovan Lek³, Jiashou Liu¹, Gaël Grenouillet³

Affiliations

¹ State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.
² University of Chinese Academy of Sciences, Beijing, China.
³ Laboratoire Evolution & Diversité Biologique, Université Toulouse III, Toulouse, France.
⁴ Key Laboratory of Freshwater Biodiversity Conservation, Ministry of Agriculture of China, Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Science, Wuhan, China.

Abstract

Despite being the most dominant and widespread small fish species in the lakes along the middle and lower reaches of the Yangtze River basin, Toxabramis swinhonis has been paid little attention by fisheries scientists and little is known about its population characteristics. For this reason, we estimated age, growth, mortality and recruitment of this species based on three shallow lakes, Biandantang Lake, Shengjin Lake and Kuilei Lake (BDT, SJH and KLH, respectively) in this region. A total of 13,585 (8,818 in BDT, 2,207 in SJH and 2,560 in KLH) individuals were collected during monthly sampling from July 2016 to September 2017. The results revealed that the age structures of T. swinhonis consisted of four age groups (0⁺-3⁺), with 0⁺-1⁺ year old fish comprising more than 98% of the samples. Allometric growth patterns were displayed by fish from all sampling sites and the von Bertalanffy growth functions estimated were L _t = 173.25 (1 - e^{-1.20 (t + 1.09)}): BDT; L _t = 162.75 (1 - e^{-1.20 (t + 1.08)}): SJH and L _t = 215.25 (1 - e^{-1.20 (t + 1.12)}): KLH, respectively. The rates of total mortality (Z), natural mortality (M) and fishing mortality (F) at BDT, SJH and KLH were computed as 5.82, 5.50 and 4.55 year^-1; 1.89, 1.87 and 1.75 year^-1; 3.93, 3.63 and 2.80 year^-1, respectively. Meanwhile, growth performance indices (φ') were 0.68 (in BDT), 0.66 (in SJH) and 0.62 (in KLH), which indicated that T. swinhonis were overfished slightly in all study areas. Area-specific recruitment patterns were similar to each other, displaying evidence of batch spawning, with major peaks in April and August, accounting for 92.21% (BDT), 88.21% (SJH) and 88.73% (KLH) of total recruitment, respectively. These results showed that brief generation-time, fast growth rate, relatively high natural mortality rate and strong reproductive capacity (r-strategies) are reasons why this species became the most dominant species in many lakes of China.

Keywords: Age and growth; Mortality and recruitment; Shallow lakes; The Yangtze River basin; Toxabramis swinhonis.

Grants and funding

This work was supported by the National Science and Technology Supporting Program of China (2012BAD25B08), the Earmarked Fund for China Agriculture Research System (CARS-45), the State Key Laboratory of Freshwater Ecology and Biotechnology (2014FBZ04), and the China Scholarship Council (CSC). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.