Seasonal and developmental diet shifts in sympatric and allopatric intertidal gobies determined by stomach content and stable isotope analysis

Abstract

Resource partitioning facilitates the coexistence of sympatric species through spatial, temporal and/or trophic strategies. Fishes living in the intertidal zone demonstrate highly adaptive plastic behaviour, including resource partitioning, through spatial and temporal shifts in diet and microhabitat. Although intertidal fish assemblages are influenced by inter-and intraspecific competition, few studies have compared the extent of resource partitioning between sympatric species in the context of trophic niche plasticity. Here we used complementary approaches, stomach content and stable isotope (δ 13 C and δ 15 N) analyses, to evaluate seasonal and developmental shifts in trophic niche position in two sympatric (Favonigobius lentiginosus and Bathygobius krefftii) and one allopatric (Bathygobius cocosensis) species of intertidal goby. The results indicate that resource partitioning in the two sympatric species varied with season, with almost no trophic niche overlap in summer to about~30% overlap in winter. Also, evidence of dietary changes was found in B. cocosensis, which is likely associated with a shift in microhabitat and intraspecific competition. The findings highlight the temporal range of behavioural plasticity in trophic niche position of intertidal gobies, which likely has high adaptive value in the dynamic intertidal zone.

Low redundancy among caddisflies sharing a mid‐mountain stream

“…Niche overlaps between different taxa are clearly visible in Figure 4. Their presence can be interpreted in terms of potential for trophic redundancy (Layman et al., 2007) and therefore potential competition (Carbia et al., 2020). Two couples ( Diplectronella / Pisulia and Anisocentropus / Leptocerina ) showed evidence of overlapping niche space.…”

Trophic ecology of co‐occurring fishes in the Sundays River Valley irrigation ponds, assessed using stable isotope and gut content analyses

“…Stable isotope analysis is a comparatively cost‐effective and integrative tool that provides information on the long‐term assimilation of dietary food sources, as well as on the trophic ecology of predator–prey interactions (Comte, Cucherousset, Boulêtreau, & Olden, 2016a; Vander Zanden et al ., 2015). In addition, stable isotope analysis can be used to provide insights into competition (Carbia et al ., 2020) and resource availability (Park et al ., 2017). Stable isotope analysis is an increasingly important tool in the study of ecological food webs and has been used in conjunction with stomach content analysis for investigating trophic dynamics in freshwater ecosystems (Eurich et al ., 2019; Peterson & Fry, 1987).…”

Molecular diet analysis of common cranes (Grus grus) under supplementary feeding based on fecal DNA metabarcoding

“…These methods were beneficial in some aspects of operation, equipment, and cost (Liu et al, 2018). However, feeding behavior observation was not suitable for nocturnal or highly alert animals (Carbia et al, 2020); stomach content analysis was not suitable for endangered and rare animals (Holechek et al, 1982). Due to physiological and technical limitations, few suitable stable isotopes can be used for rare avian diet analysis (Inger & Bearhop, 2010).…”

“…Diet can reveal the link between animals and their habitats. In prior studies of animals in general, diets were mainly determined by direct feeding behavior observation (Avilés et al, 2002), stomach content analysis (Carbia et al, 2020), fecal microhistological method (Holechek et al, 1982; Zhan et al, 2007), cafeteria utilization method (Rothwell & Stock, 1988), and stable isotope analysis (Carbia et al, 2020). These methods were beneficial in some aspects of operation, equipment, and cost (Liu et al, 2018).…”