Page 189 - 《水产学报》2025年第11期

王孟，等 水产学报, 2025, 49(11): 119315

DNA metabarcoding-based diet analysis of Salmo trutta fario in
the Yadong River

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WANG Meng , CHEN Yongxia , QIAN Jianshuo , HE Dekui 2*
1. College of Life Sciences, Hebei University, Baoding 071002, China;
2. Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China

Abstract: Salmo trutta fario is a second-level protected wild animal in the Xizang Autonomous Region, distributed only in the
Yadong River segment in Yadong County, Shigatse City, Xizang. In recent years, due to overfishing and changes in hydrolo-
gical conditions, the population resources of wild S. trutta have rapidly declined. Due to the difficulty in obtaining samples,
there are few studies on the feeding habits of S. trutta. The analysis of the food composition of S. trutta is helpful for under-
standing its population dynamics and ecological functions, and it is of great significance for the protection and restoration of
fishery resources. In this study, 26 wild S. trutta were collected from Yadong River in Yadong County, and 22 intestinal con-
tents were obtained. Two pairs of universal primers targeting the highly variable regions of 18S rRNA V4 and COI genes were
used to identify the food composition of intestinal contents. The results showed that a total of 17 food taxa were obtained: Man-
todea, Calanoida, Cladocera, Araneae, Coleoptera, Cyclopoida, Diptera, Ephemeroptera, Haplotaxida, Hemiptera, Hymenop-
tera, Lepidoptera, Lumbriculida, Melosirales, Parachela, Ploima, and Trichoptera. Among all food taxa, Diptera had the highest
frequency of occurrence, percent of occurrence, weighted percent of occurrence, and relative read abundance (18S rRNA were
81.82%, 26.87%, 35.53%, and 53.77%; COIwere 81.82%, 29.03%, 39.09%, and 45.14%), followed by Lepidoptera (18S rRNA
were 59.09%, 19.40%, 19.02%, and 14.33%; COIwere 45.45%, 16.13%, 16.32%, and 21.39%). Paired Wilcoxon test showed
that the amplicon sequence variants (ASVs) of food taxa amplified by the 18S rRNA region were significantly higher than those
amplified by the COI region, and species annotation chi-square test showed that the annotation success rate of the COI region
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was higher (χ =43.47, df=4). Overall, S. trutta mainly feeds on aquatic insects, with Diptera being the main food composition.
In addition, planktonic animals and planktonic plants were also found, which may be accidentally ingested during predation. In
the process of analyzing food composition using DNA barcoding, there are differences in the results obtained with different
molecular markers, and the results obtained by using two or more molecular markers together will be more comprehensive. The
results of this study can provide reference for understanding the survival status of wild S. trutta populations and formulating
protection policies.
Key words: Salmo trutta fario; dietary composition; 18S rRNA; COI
Corresponding author: HE Dekui. E-mail: hedekui@ihb.ac.cn
Funding projects: Second Tibetan Plateau Scientific Expedition Program (2024QZKK0200); National Natural Science Found-
ation of China (32070436); Project of the Chinese Academy of Sciences for the Strategic Biological Resources Program

中国水产学会主办 sponsored by China Society of Fisheries https://www.china-fishery.cn
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