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Stable isotope analysis reveals ontogenetic feeding shifts in Pacific blue marlin ( Makaira nigricans ) off eastern Taiwan
Author(s) -
Chang ChingTsun,
Chiang WeiChuan,
Chang YunChen,
Musyl Michael K.,
Sun ChiLu,
Madigan Daniel J.,
Carlisle Aaron B.,
Hsu HungHung,
Chang QiXuan,
Su NanJay,
Ho YuanShing,
Tseng ChenTe
Publication year - 2019
Publication title -
journal of fish biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.672
H-Index - 115
eISSN - 1095-8649
pISSN - 0022-1112
DOI - 10.1111/jfb.13902
Subject(s) - trophic level , biology , predation , apex predator , ontogeny , ecomorphology , isotope analysis , ecology , zoology , habitat , genetics
To gain a better understanding of the trophic ecology of Pacific blue marlin Makaira nigricans off eastern Taiwan, nitrogen and carbon stable isotopes (δ 15 N and δ 13 C) and Bayesian mixing models were used to explore trophic dynamics and potential ontogenetic feeding shifts across M. nigricans of different size classes. Makaira nigricans samples from east of Taiwan ( n = 213) and Palau ( n = 37), as well as their prey ( n = 70), were collected during 2012 and 2013. Results indicated increases in δ 15 N with size, with values of larger size classes (> 200 cm eye‐to‐fork length; L EF ) significantly higher than those < 200 cm L EF . Values of δ 13 C were negatively correlated with size. Makaira nigricans > 200 cm L EF had the highest estimated trophic position (4.44) and also exhibited ontogenetic changes in trophic position. Large M. nigricans fed more on dolphinfish Coryphaena hippurus and hairtail Trichiurus lepturus , while smaller M. nigricans consumed smaller forage fish ( e.g ., moonfish Mene maculata ) and cephalopods. These changes may relate to greater swimming speeds and vertical habitat use in larger M. nigricans , allowing capture and consumption of larger prey items at higher trophic positions. The high trophic level of M. nigricans east of Taiwan confirms its important role as an apex predator in marine food webs and how ecological role changes with size.