February 2025
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Aquatic Ecology
The energetic balance of organisms depends on the energy assimilated from food to fulfill vital functions (e.g. maintenance and somatic growth). Temperature drives the energetic balance and the performance of organisms. Evaluating the effect of temperature on multiple components is relevant to understanding the response to climate change. Here, we evaluated the thermal performance curve (TPC) for oxygen consumption (OC), ammonia excretion (AER) and ingestion rates (IR) in temperatures from 6 to 30 °C in the freshwater apple snail Pomacea sp. Additionally, we evaluated the evolution of somatic growth, IR and survival for ca. 400 days in snails exposed to fluctuating environmental temperature (OT; T range = 7–27 °C) and laboratory conditions (IT; T range = 12–19.6 °C). The TPC of OC and AER showed a unimodal pattern, with an optimum at 22 and 28 °C, respectively. IR showed a monotonic increase towards the warmest temperature (30 °C). Between ~ 15–20 °C weight increases with temperature while IR remains constant; suggesting snails invest energy mostly in growth. The final size achieved by snails in IT and OT were similar (~ 500 mg) while maximum IR was lower in IT (~ 400 mg/g.d vs ~ 800 mg/g.d of ET). Survival was similar between treatments, but growth parameters fitted by a modified Von Bertalanffy growth function with a temperature dependence on growth coefficient differed. TPC were different, which could generate mismatch between resource acquisition, assimilation and excretion affecting growth patterns. Evidence on a high capacity to deal with large thermal variability suggests adaptations of the snail to cope with climate change.