Relationship between individual metabolic rate and patch departure behaviour: evidence from aquatic gastropods

Abstract

Individual energy requirements are tightly related to individual resource use and by extension of space‐use patterns and other traits at higher levels of the ecological hierarchy. However, there is still little experimental evidence linking individual energetics and space‐use behaviour. Individual energy requirements scale mainly with body size and temperature, but these do not explain all individual variation. Therefore, studies focused on inter individual variation in resource and space use behaviour can be used to frame foraging dynamics in an energy perspective. We empirically tested the hypothesis of a relationship between individual energetics and patch departure behaviour using as model organisms four small species (body mass ranging from 0.4 to 14 mg AFDW) of aquatic gastropods strongly differing in adult size: Galba truncatula, Bithynia tentaculata, Theodoxus fluviatilis and Ecrobia ventrosa (in descending order of size). Motility tests were performed in controlled microcosm conditions. The tests were designed to classify the specimens as either low motility (not inclined to abandon the patch) or high motility (likely to abandon the patch). The tests entailed measuring the propensity of the individuals to abandon a limited resource patch (2 g DW of conditioned Phragmites australis leaves) within a given amount of time (24 h) when foraging with conspecifics under conditions where competition for food is expected to increase over time due to resource depletion. The individual standard metabolic rate of the tested specimens was measured via open flow respirometry and compared across motility classes at intra‐ and interspecific level. At both levels, we observed that individuals with higher standard metabolic rates were more inclined to abandon the patch. This finding establishes a link between foraging theory and competitive coexistence mechanisms.

A new approach to assessing the space use behavior of macroinvertebrates by automated video tracking

“…Thus, larger individuals gave up the resource patch earlier and travelled further in search of food than smaller ones. Similarly, recent studies have observed the negative size dependency of giving‐up time among several Gastropod species (Cozzoli et al., 2018, 2020).…”

“…Similarly, recent studies have observed the negative size dependency of giving-up time among several Gastropod species (Cozzoli et al, 2018(Cozzoli et al, , 2020. (Gillooly et al, 2001;West et al, 1997).…”

“…Individuals’ energy demands are broadly dependent on body size (Gillooly et al., 2001; Kleiber, 1932; West et al., 1997) and closely related to space use features, for example, giving‐up time, density, and home range size (Börger et al., 2020; Brown, 1988; Ofstad et al., 2016). Therefore, differences in size may involve changing foraging strategies in order to meet energy needs, for example, ranging farther afield (larger home range) (Laver & Alexander, 2018) and giving up the patch earlier (shorter giving‐up time) and at higher densities of remaining resources (higher giving‐up density) when the absolute resource density remains constant (Basset & De Angelis, 2007; Brown et al., 1994; Cozzoli et al., 2020). The study of size dependency in individual space and resource use behavior can help to deepen our understanding of individual and population space and resource use, which, in turn, may enable prediction of future aquatic ecosystem functioning and resource availability.…”

Size–Abundance Relationships of Freshwater Macroinvertebrates in Two Contrasting Floodplain Channels of Rhone River

“…For reasons that are still not completely understood, the metabolic scaling slope of benthic macroinvertebrates often shows less steep slopes (i.e., ~0.30 to ~0.55) than the −0.75 value. Whether this variation in macroinvertebrate metabolic scaling slope is related to environmental factors, such as water temperature [58,59] and biological factors, such as predation pressure [60,61], is less known. Moreover, this variation of metabolic responses in relation to predation threats may be temperature-dependent [62,63].…”

The behavior of Gammarus aequicauda (crustacea, amphipoda) during predation on chironomid larvae: Sex differences and changes in precopulatory mate‐guarding state

“…Animals determine behaviors regarding their physiological needs and reproductive goals (Cozzoli et al, 2018(Cozzoli et al, , 2020Prato et al, 2006;Shokri et al, 2019Shokri et al, , 2021Shuhaimi & Pascoe, 2001), once they reach sexual maturity, new dimensions would be added to their internal state and hence, the organism foraging decisions (Becker et al, 2012;Cruz-Rivera et al, 2017;Mowrey & Portman, 2012;Ward, 1985Ward, , 1986. Sex-related differences were shown in G. aequicauda during its feeding as a grazer on two green algae species (Cruz-Rivera et al, 2017).…”