Dietary niche divergence between two invasive fish in Mediterranean streams

Abstract

Clarifying the mechanisms associated with the coexistence of invasive species is important to understand the overall impact of multiple invasions on recipient communities. Here we examined whether divergence or convergence in dietary niche occurred when invasive Lepomis gibbosus and Australoheros facetus coexist in Iberian streams. We used stomach content analyses to determine dietary niche composition, width, and overlap in allopatric and sympatric counterparts in the Lower Guadiana throughout the dry-season. The variations in dietary niche between pumpkinseed and the cichlid were consistent with predictions derived from the niche divergence hypothesis. Although there were no changes in the use of plant material from allopatry to sympatry in either species, sympatric pumpkinseed and the cichlid displayed marked shifts in the use of animal prey and a decrease in niche width relative to allopatric counterparts. Moreover, sympatric pumpkinseed and cichlid showed similar niche width but differed significantly in plant and animal prey use. Taken together these results suggest that divergence in dietary niches may play a role in mediating coexistence of multiple invaders in Iberian streams.

Diet of European Catfish in a Newly Invaded Region

“…A larger number of iterations was used in order to reduce stress values to <0.2, as the standard approach resulted in lack of component convergence; this was possibly due to low sample size. A follow up analysis of similarity (ANOSIM) was attempted, but trust in the results was not satisfactory and therefore was not included, following Gkenas et al (2019) [33].…”

Trophic resource partitioning drives fine‐scale coexistence in cryptic bat species

“…given Several studies have identified trophic niche shifts from allopatry to sympatry, for instance between morphologically similar fish (Gkenas et al, 2019;Schmitt & Coyer, 1983) and reptile species (Huey et al, 1974;Klawinski et al, 1994). However, in bats, previous coexistence studies looking at trophic ecology only focused on sympatric or syntopic populations, and rarely found evidence of trophic resource partitioning.…”

Trophic resource partitioning drives fine-scale coexistence in cryptic bat species

“…Several studies have identified trophic niche shifts from allopatry to sympatry, for instance between morphologically similar fish (Gkenas et al, 2019;Schmitt & Coyer, 1983) and reptile species (Huey et al, 1974;Klawinski et al, 1994). However, in bats, previous coexistence studies looking at trophic ecology only focused on sympatric or syntopic populations, and rarely found evidence of trophic resource partitioning.…”