Analysis of food preference and competition based on stomach contents of fish species inhabiting fresh and brackish waters in South Korea

Abstract

Food resource is one of the most crucial exogenous factors for determining species distribution and abundance, as well as the ecological structure of populations and communities (Stergiou & Karpouzi, 2002;Wootton, 2012). The feeding activity of animals provides energy for the maintenance of life, somatic growth and reproduction, and forms a link between different trophic levels, thus inducing food competition. Producers and consumers are linked by their feeding activities through intra-and interspecific competition

Hierarchical Interaction between Food Diversity and Competition in Brackish Fish Species in South Korea

“…In addition, conducting meta-analyses on speciesspecific food webs allows for the analysis of energy flow in aquatic food webs. Some publications have presented information on food sources as the %N, but it is essential to have information on individual numbers and biomass for a more advanced understanding [12]. Studying food sources by analyzing gut contents can be challenging in terms of identifying digested prey, and there may be differences in the sub-classification of taxonomic groups at the genus and species levels depending on the researcher.…”

“…Stable isotope studies in mangrove, marsh, and reed habitats showed that juvenile fishes ate mainly epilithic diatoms and algae rather than macrophytes [11]. While many fish food source studies focus on potential food source estimation due to the simplicity of the stable isotope method, they lack practical ecosystem food web connectivity and analysis [11,12]. Indeed, few studies have attempted to arrange the entire fish-food assemblage into an ecosystem perspective with an ecological network analysis [13][14][15].…”

“…However, all fish cannot survive by feeding only on attached algae, and downstream, benthic invertebrates will still be a preferred food source for fish [12]. Fish do not rely on a single food source for growth and development [11].…”

“…In particular, benthic invertebrates have been underestimated regarding their role in the food web as food sources for fish. Despite the high preference and competition for benthic invertebrates as food sources, freshwater fish can coexist due to high-density food sources, such as Chironomidae [12,16]. However, in estuaries, aquatic insect tolerance to salt is lower, resulting in a significant decrease in their population density.…”