Interactions between a planktivorous fish and planktonic microcrustaceans mediated by the biomass of aquatic macrophytes

Abstract

Habitat complexity is recognized to mediate predator–prey relationships by offering refuge or not. We investigated the availability of planktonic microcrustaceans and the diet of a planktivorous fish (Hyphessobrycon eques) at different levels (low, intermediate and high) of aquatic macrophyte biomass. Sampling was carried out in a river with low flow speed, located in a Neotropical floodplain. We collected fish and microcrustaceans in macrophyte stands with variations in biomass. There were no differences in microcrustacean density in the water among the levels of macrophyte biomass, but microcrustacean richness and diet composition of H. eques differed. Microcrustacean richness and trophic niche breadth of the planktivorous fish were higher in high biomass stands. There was high consumption of a small cladoceran species in low macrophyte biomass, which was replaced by larger species, such as copepods, in intermediate and high biomass. Thus, the selection of some species was different among the biomass levels. These results suggest that plant biomass plays an important role in the interaction between fish and microcrustaceans, and prey characteristics such as size, escape ability and energy value make them more or less subject to predation by fish according to habitat structuring.

Composition, Distribution, and Biodiversity of Zooplanktons in Tropical Lentic Ecosystems with Different Environmental Conditions

“…This observation aligned with Brito et al [48] who reported that the high occurrence of zooplankton species within floodplain regions can be attributed, in part, to the substantial presence of extensive aquatic macrophyte cover. Submerged or free-floating macrophytes foster an elevated species diversity by expanding the available colonization area, enhancing the availability of food resources, and providing a refuge from predation [49][50][51]. Prior investigations have also demonstrated that habitat intricacy, brought about by aquatic macrophytes, functions as a predictive factor for biodiversity.…”

“…Prior investigations have also demonstrated that habitat intricacy, brought about by aquatic macrophytes, functions as a predictive factor for biodiversity. This complexity contributes to species richness and facilitates the expansion of a more extensive genetic reservoir within the zooplankton community [46,51,52].…”

Ecology of Aquatic Macrophytes in Brazil: The Legacy of Francisco De Assis Esteves

“…They also provide substrates for algae and invertebrates attachment (dos Santos et al 2013, Cunha et al 2012), but they attract predators, which further increase the diversity within macrophyte stands (Thomaz & Cunha 2010). Numerous studies retrieved by our search addressed the role of macrophytes as a refuge for zooplankton (e.g., dos , Quirino et al 2021 and macroinvertebrates (e.g., Padial et al 2009), demonstrating how macrophytes can influence predator-prey interactions. Macrophytes provide an efficient physical and visual barrier against predators, decreasing predation rates and allowing different organisms to successfully explore these habitats (Pelicice et al 2008, Dibble & Pelicice 2010.…”

Associations between submerged macrophytes and fish communities at two spatial scales in 88 temperate shallow lakes

“…Submerged macrophytes also affect the spatial distribution of organisms as they provide spawning substrate, nursery areas, refuge against predators, and food (Dibble et al, 1996;Quirino, de Mello, et al, 2021;Slade et al, 2005).…”

“…Particularly in shallow lakes, macrophytes play a critical role by stabilising the sediment, assimilating nutrients, and modifying the trophic structure, all contributing to maintain a clear water state (Jeppesen et al, 1998; Thomaz, 2021). Submerged macrophytes also affect the spatial distribution of organisms as they provide spawning substrate, nursery areas, refuge against predators, and food (Dibble et al, 1996; Quirino, de Mello, et al, 2021; Slade et al, 2005).…”