Trophic Dynamics and Feeding Ecology of Skipjack Tuna (Katsuwonus pelamis) off Eastern and Western Taiwan

Molecules

Ching-Lung Chiang¹  Sheng-Ping Wang¹  Daniel J. Madigan²  Hung-Hung Hsu³  Wei-Chuan Chiang³  Fu-Yuan Tsai³  Yun-Chen Chang⁴  Shiow-Mei Lin⁵  Ching-Ting Sun⁵  Mei-Ying Zhuang⁵  Lu-Chi Chen⁵ 

[1] Department of Environmental Biology and Fishery Science, National Taiwan Ocean University, Jhongjheng District, Keelung 202, Taiwan;Department of Integrative Biology, University of Windsor, Windsor, ON N9B 3P4, Canada;Eastern Marine Biology Research Center, Fisheries Research Institute, Chenggong 961, Taiwan;Marine Fisheries Division, Fisheries Research Institute, Jhongjheng District, Keelung 202, Taiwan;Penghu Marine Biology Research Center, Fisheries Research Institute, Magong City 880, Taiwan;

关键词: pelagic;    predator;    diet;    stable isotope analysis;    Bayesian mixing models;    Northwest Pacific;   

DOI  :  10.3390/molecules27031073

来源: DOAJ

【 摘 要 】

The skipjack tuna (Katsuwonus pelamis) is a mesopredator fish species with seasonal abundance in waters off Taiwan. Regional ecological and life-history information has been historically lacking for this species. In recent years, stable isotope analysis (SIA) of carbon and nitrogen has been used to assess predator feeding ecology and broader ecosystem trophic dynamics. This study evaluated comparative skipjack feeding ecology in distinct regions off Taiwan, combining traditional stomach content analysis with SIA of individuals off western (n = 43; 2020) and eastern (n = 347; 2012–2014 and n = 167; 2020) Taiwan. The stomach content analysis showed the most important prey to be ponyfish (Photopectoralis bindus) in western Taiwan and epipelagic squids (Myopsina spp.) and carangids (Decapterus macrosoma;) in eastern Taiwan from 2012 to 2014 and epipelagic carangids (Decapterus spp.) and flying fishes (Cheilopogon spp.) in eastern Taiwan in 2020, suggesting that the skipjack tuna is a generalist predator across regions. In contrast, time-integrated diet estimates from Bayesian mixing models indicated the importance of cephalopods and crustaceans as prey, potentially demonstrating more mesopelagic feeding in less productive waters during skipjack migrations outside the study regions. Skipjack off western Taiwan had a slightly higher estimated trophic position than in the waters off eastern Taiwan, potentially driven by the varying nutrient-driven pelagic food web structures. Skipjack SI values increased with body size off eastern Taiwan but not in western waters, suggesting that opportunistic predation can still result in different predator–prey size dynamics between regions.

【 授权许可】

Unknown