摘要
Accurate diet identification of top predators is crucial to fully understand their ecological roles.Compared to terrestrial animals,gathering dietary information from cetaceans is notoriously difficult.Here,we applied a multilocus metabarcoding approach to investigate the diet of vulnerable Indo-Pacific humpback dolphins and Indo-Pacificfinless porpoises from the Pearl River Estuary(PRE),China.Our analyses identified 21 preyfish species from the 42 humpback dolphin stomachs,as well as 10 species offish and 1 species of cephalopod from the 13finless porpoise stomachs.All of the taxa were assigned to the species level,highlighting that the multimarker approach could facilitate species identification.Most of the prey species were small-and medium-sizedfishes that primarily fed on zooplankton.The calculated similarity index revealed a moderated dietary overlap between the 2 cetaceans,presumably due to the feeding of the 2 predators in association withfishing vessels in the PRE.A more diverse diet was observed in humpback dolphins in the closedfishing season compared to thefishing season,implying the influence on the dolphin diet due to the availability of commercialfishery resources.However,according to the results of species rarefaction curves,ourfindings on the feeding habits of the 2 cetaceans are still limited by insufficient sample size and therefore should be interpreted with caution.This study represents afirst attempt to apply the multilocus DNA metabarcoding technique in the diet analysis of small cetaceans,although more efforts are needed to improve this type of analysis.
基金
supported by the Natural Science Foundation of Guangdong Province(2017A030308005)in China
the National Natural Science Foundation of China(41576128,42007225)
Guangdong Basic and Applied Basic Research Foundation(2020A1515010910)in China
China Postdoctoral Science Foundation(2019M653153)
Fundamental Research Funds for the Central Universities(19lgpy95)
Ocean Park Conservation Foundation of Hong Kong(MM01.1718)
Innovation Group Project of Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)(311021004,311020003).
