Comparison of morphological and DNA-based techniques for stomach content analyses in juvenile chum salmon Oncorhynchus keta: a case study on diet richness of juvenile fishes

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• 作者：Sakiko Orui Sakaguchi ; Shigeru Shimamura ; Yuichi Shimizu ; Gen Ogawa…
• 关键词：Diet analysis ; DNA barcoding ; Morphological identification ; Peptide nucleic acid ; Polymerase chain reaction clamping
• 刊名：Fisheries Science
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：83
• 期：1
• 页码：47-56
• 全文大小：
• 刊物主题：Fish & Wildlife Biology & Management; Freshwater & Marine Ecology; Food Science;
• 出版者：Springer Japan
• ISSN：1444-2906
• 卷排序：83

文摘

To identify the stomach contents of marine organisms, morphological observations are commonly conducted. However, the results obtained by this traditional method are frequently biased, as it is difficult to detect partially digested, soft-bodied organisms. To resolve this, recent studies have used DNA-based (DNA barcoding) analyses to examine the diet breadth of marine organisms. Here, we compared the prey richness of juvenile fishes using morphological observations and DNA-based analyses, with a focus on juvenile chum salmon Oncorhynchus keta. A higher number of prey taxa were successfully identified using DNA-based analyses than morphological observations. However, we also noticed several shortcomings of the DNA-based analyses, as reported in other diet-analysis studies that used molecular techniques. For example, the degree of digestion among prey taxa might have resulted in differential sensitivity to DNA detection. Additionally, several prey taxa could not be precisely identified, as the sequence data for some of the targeted organismal groups are unavailable in public gene databases. Remarkably, it is also possible that DNA-based analyses detected secondary prey, and therefore, the richness of prey taxa was likely overestimated. Thus, dietary analyses of juvenile fishes need to be carefully conducted, considering the respective advantages and disadvantages of DNA-based and morphological techniques.