Aquatic Macrophytes Shape the Foraging Efficiency, Trophic Niche Breadth, and Overlap among Small Fish in a Neotropical River

Aquatic macrophytes are generally recognized to influence fish–prey interactions. We assessed how fish consume particular foods, and how their foraging efficiency, trophic niche breadth, and niche overlap respond to gradients of macrophyte density and diversity. We sampled fish and macrophytes in 30...

Full description

Saved in:
Bibliographic Details
Published in:Water (Basel) 2022-11, Vol.14 (21), p.3543
Main Authors: Quirino, Bárbara Angélio, Thomaz, Sidinei Magela, Jeppesen, Erik, Søndergaard, Martin, Dainez-Filho, Mário Sérgio, Fugi, Rosemara
Format: Article
Language:English
Subjects:
Algae
Aquatic plants
Biomass
Competition
Detritus
Diet
Efficiency
Fish conservation
Food
Foraging behavior
Herbivorous fish
Herbivory
Invertebrates
Littoral environments
Littoral zone
Macrophytes
Niche breadth
Planting density
Predator-prey interactions
Prey
Resource availability
Rivers
Statistical models
Vegetation
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Aquatic macrophytes are generally recognized to influence fish–prey interactions. We assessed how fish consume particular foods, and how their foraging efficiency, trophic niche breadth, and niche overlap respond to gradients of macrophyte density and diversity. We sampled fish and macrophytes in 30 stands distributed over a 13.7 km stretch of the littoral zone of a river in Brazil. By generating generalized linear models, we showed that increasing macrophyte density (from 366 to 7066 g DW m−3) favored herbivory and fish foraging efficiency. Beta regressions showed that fish reduced their trophic niche breadth along the gradient of macrophyte density, while niche overlap increased until a certain extent of plant density when species started to segregate the niche more strongly. However, niche breadth responses varied according to the trophic guild considered, with omnivorous and herbivorous fish generally showing opposite responses. Macrophyte diversity was important for the preferred food items of the fish, with stomach contents shifting from higher plants, algae, and detritus to insects with increasing macrophyte diversity. Therefore, in addition to the presumable effects of macrophyte density on resource availability and prey encounter rates, our findings highlight the importance of maintaining diverse macrophyte stands for the conservation of fish diversity.
ISSN:2073-4441
2073-4441
DOI:10.3390/w14213543