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Trophic niche of the Pacific Sierra ( Scomberomorus sierra ) in the southeastern Gulf of California: Assessing its importance as a predator and prey (Mesopredator) in the food web
Author(s) -
TorresRojas Yassir Edén,
Amezcua Felipe,
SotoJimenez Martin Federico
Publication year - 2020
Publication title -
journal of applied ichthyology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.392
H-Index - 62
eISSN - 1439-0426
pISSN - 0175-8659
DOI - 10.1111/jai.14066
Subject(s) - mesopredator release hypothesis , trophic level , biology , ecology , apex predator , predation , carnivore , intraguild predation , food web , predator , niche , food chain
The identification of interspecific links (trophic niche) is important to characterize resource use of a predator, and to know its trophic role (for example, mesopredator or top predator) in the food web. In this study, we examined: a) the trophic ecology of Scomberomorus sierra as a predator (niche breadth, trophic overlap, and trophic position) and b) its presence as a prey in the diets of the region´s top predators, to evaluate the critical link of S. sierra as a probable mesopredator in the food web of the southeastern Gulf of California (GC). Based on %PSIRI, the dominant diet of S. sierra were engraulids and cephalopods. The diet was similar between sexes and among size‐classes. However, the isotopic niche breadth values and δ 15 N variance (>1) reflect a broad niche for young adults likely related to a) changes in morphology (e.g., size of the mouth), b) development of the visual system, and c) changes in the energy requirements of the species reproductive stages. Seasonal changes in prey species’ availability and abundance resulted in isotopic variations, indicating that S. sierra is an opportunistic predator. A wide range in trophic position value (from 3.8 to 4.2) indicated that it also is an intermediary carnivore, with a high degree of trophic plasticity. Although S. sierra has not a dominant role in top predators’ diets, they share some prey species such as anchovies and other fish, depending on predator size. Therefore, S. sierra is a species with many prey‐predator relationships in the southeastern GC food webs that may be considered a critical trophic link. This information is crucial for an ecosystem‐based fisheries management in the Gulf of California.