Ontogenetic diet shifts and feeding dynamics of Trichiurus japonicus Temminck & Schlegel, 1844, off Guishan Island, Southern East China Sea

Trophic ecology of largehead hairtail Trichiurus japonicus in the South Sea of Korea revealed by stable isotope and stomach content analyses

“…The feeding characteristics observed in the species may be explained by seasonally varying patterns of feeding dynamics, ontogenetic dietary shifts, and dietary composition. A wide range of prey compositions for largehead hairtail as a carnivorous species has been reported from several other seas, identifying principal prey items, including zooplankton, shrimps, cephalopods, and fish, based on stomach content analysis (Martins et al, 2005;Mammel et al, 2022). Our study provides valuable information for understanding population variations in the dietary composition and trophic position (TP) of largehead hairtails in different foraging areas resulting from opportunistic and variable feeding behavior.…”

“…In Korea, its annual catch was approximately 120,000 t in the 1980s; since then, the annual catch has declined gradually from an average of approximately 60,000-80,000 t in the 2000s to an average of approximately 44,000 t in the last five years (KOSIS, 2019). Due to its increasing commercial value and decreasing catch volumes, the basic ecology, life history, population dynamics, habitat, and environmental conditions of the largehead hairtail are being widely studied (Kim et al, 2005;He et al, 2014;Kim et al, 2020;Sun et al, 2020;Mammel et al, 2022). In addition to basic biological knowledge, trophic ecology is essential for the effective management and conservation of this specific fish population.…”

“…Hairtails are high trophic level predators that play a key role in the marine food web, as they control lower trophic level species (e.g., fish, shrimp, and squid) through top-down processes (Martins et al, 2005;Yan et al, 2011). Since the survival and abundance of the hairtail can potentially affect the population dynamics of other fish, understanding their feeding ecology, based on energy flow within marine ecosystems, is critical for the assessment of commercial fisheries resources (Mammel et al, 2022). Accordingly, many studies have addressed the feeding characteristics, dietary composition, ontogenetic changes, and spatiotemporal variations in the diet of hairtails (Lee, 1978;Bakhoum, 2007;Liu et al, 2009;Yan et al, 2011;Hamaoka et al, 2014;Mammel et al, 2022).…”

“…Since the survival and abundance of the hairtail can potentially affect the population dynamics of other fish, understanding their feeding ecology, based on energy flow within marine ecosystems, is critical for the assessment of commercial fisheries resources (Mammel et al, 2022). Accordingly, many studies have addressed the feeding characteristics, dietary composition, ontogenetic changes, and spatiotemporal variations in the diet of hairtails (Lee, 1978;Bakhoum, 2007;Liu et al, 2009;Yan et al, 2011;Hamaoka et al, 2014;Mammel et al, 2022). However, most of the research was limited to Chinese hairtail populations inhabiting China and the Yellow Sea.…”

“…A combination of stable isotope and stomach content analyses has rarely been applied to this species (Hamaoka et al, 2014). In addition, most studies have investigated the feeding characteristics of T. lepturus, whereas information on the trophic ecology of T. japonicus is very limited (Mammel et al, 2022). We anticipated that if the dietary composition of T. japonicus changes in association with its ontogeny and season, its tissue isotopic signatures would reflect this change.…”