Effects of acute and chronic temperature changes on the functional responses of the dogfish Scyliorhinus canicula (Linnaeus, 1758) towards amphipod prey Echinogammarus marinus (Leach, 1815)

Abstract

Predation is a strong driver of population dynamics and community structure and it is essential to reliably quantify and predict predation impacts on prey populations in a changing thermal landscape. Here, we used comparative functional response analyses to assess how predator-prey interactions between dogfish and invertebrate prey change under different warming scenarios. The Functional Response Type, attack rate, handling time and maximum feeding rate estimates were calculated for Scyliorhinus canicula preying upon Echinogammarus marinus under temperatures of 11.3°C and 16.3°C, which represent both the potential daily variation and predicted higher summer temperatures within Strangford Lough, N. Ireland. A two x two design of BPredator Acclimated^, BPrey Acclimated^, BBoth Acclimated^, and BBoth Unacclimated^was implemented to test functional responses to temperature rise. Attack rate was higher at 11.3°C than at 16.3°C, but handling time was lower and maximum feeding rates were higher at 16.3°C. Non-acclimated predators had similar maximum feeding rate towards nonacclimated and acclimated prey, whereas acclimated predators had significantly higher maximum feeding rates towards acclimated prey as compared to nonacclimated prey. Results suggests that the predator attack rate is decreased by increasing temperature but when both predator and prey are acclimated the shorter handling times considerably increase predator impact. The functional response of the fish changed from Type II to Type III with an increase in temperature, except when only the prey were acclimated. This change from population destabilizing Type II to more stabilizing Type III could confer protection to prey at low densities but increase the maximum feeding rate by Scyliorhinus canicula in the future. However, predator movement between different thermal regimes may maintain a Type II response, albeit with a lower maximum feeding rate. This has implications for the way the increasing population Scyliorhinus canicula in the Irish Sea may exploit valuable fisheries stocks in the future.

Invasive crayfish outperform Potamonautid crabs at higher temperatures

“…As a result, more stimuli are provided to the predator and the encounter rate (i.e. attack parameter) is increased (South & Dick, 2017) as observed when temperatures were increased to 28°C in this study. Mismatches in foraging and digestion capacity will occur when the effects of temperature change are of different magnitude and direction between species; however, this might only be detected at different time scales (i.e.…”

“…Our results support the ecological matching hypothesis, which predicts that the performance of IAS are higher at temperatures that most closely match their thermal optima (Iacarella et al., 2015). As per the metabolic theory of ecology (Englund et al., 2011; Huey & Stevenson, 1979; Jobling, 1981), temperature increase will also have increased prey metabolism, increasing the frequency of prey movement, speed, and boldness (although these effects will also be apparent in the predator) (van Baalen et al., 2001; Nowicki et al., 2012; South & Dick, 2017). As a result, more stimuli are provided to the predator and the encounter rate (i.e.…”

“…Mismatches in foraging and digestion capacity will occur when the effects of temperature change are of different magnitude and direction between species; however, this might only be detected at different time scales (i.e. acclimation duration) (South & Dick, 2017).…”

Warming can destabilize predator–prey interactions by shifting the functional response from Type III to Type II

“…Despite the unknown relationship between q and temperature, temperature driven type shifts of the functional response have been reported before. In fact, both the stabilizing (from Type II to Type III, e.g., Mohaghegh, De Clercq, & Tirry, ; South & Dick, ; Wang & Ferro, ; Ziaei Madbouni, Samih, Namvar, & Biondi, ) and the destabilizing transition (from Type III to Type II, see Dong, Liu, Xie, Cong, & Wang, ; Taylor & Collie, ) have previously been found. In some cases, the functional response shifted back and forth between types with warming (Eggleston, ; Mondal, Chandra, Bandyopadhyay, & Ghosh, ).…”

Warming can destabilise predator-prey interactions by shifting the functional response from Type III to Type II

“…In fact, both the stabilising (from Type II to Type III, e.g. Mohaghegh, De Clercq, & Tirry, 2001; South & Dick, 2017; Wang & Ferro, 1998; Ziaei Madbouni, Samih, Namvar, & Biondi, 2017) and the destabilising transition (from Type III to Type II, see Dong, Liu, Xie, Cong, & Wang, 2017; Taylor & Collie, 2003) have previously been found. In some cases, the functional response shifted back and forth between types with warming (Eggleston, 1990; Mondal, Chandra, Bandyopadhyay, & Ghosh, 2017).…”