Abstract
Environmentally-induced changes in fitness are mediated by direct effects on physiology and behaviour, which are tightly linked. We investigated how predicted ocean warming (OW) and acidification (OA) affect key ecological behaviours (locomotion speed and foraging success) and metabolic rate of a keystone marine mollusc, the sea hare Stylocheilus striatus, a specialist grazer of the toxic cyanobacterium Lyngbya majuscula. We acclimated sea hares to OW and/or OA across three developmental stages (metamorphic, juvenile, and adult) or as adults only, and compare these to sea hares maintained under current-day conditions. Generally, locomotion speed and time to locate food were reduced ~1.5- to 2-fold when the stressors (OW or OA) were experienced in isolation, but reduced ~3-fold when combined. Decision-making was also severely altered, with correct foraging choice nearly 40% lower under combined stressors. Metabolic rate appeared to acclimate to the stressors in isolation, but was significantly elevated under combined stressors. Overall, sea hares that developed under OW and/or OA exhibited a less severe impact, indicating beneficial phenotypic plasticity. Reduced foraging success coupled with increased metabolic demands may impact fitness in this species and highlight potentially large ecological consequences under unabated OW and OA, namely in regulating toxic cyanobacteria blooms on coral reefs.
Highlights
Environmentally-induced changes in fitness are mediated by direct effects on physiology and behaviour, which are tightly linked
Our results show that behavioural traits linked to foraging and metabolic rates of a keystone marine mollusc are affected by exposure to future sea surface temperature (SST) conditions[1]
Certain behavioural modifications were less severe for developmentally compared to adult acclimated sea hares, suggesting a potential for adaptive developmental plasticity to future climate change conditions that is not observed in animals subjected to short-term changes in their environment as adults
Summary
Environmentally-induced changes in fitness are mediated by direct effects on physiology and behaviour, which are tightly linked. We investigated how predicted ocean warming (OW) and acidification (OA) affect key ecological behaviours (locomotion speed and foraging success) and metabolic rate of a keystone marine mollusc, the sea hare Stylocheilus striatus, a specialist grazer of the toxic cyanobacterium Lyngbya majuscula. Any effects of OW and OA in the coming decades on the behaviour and physiology of marine invertebrates, molluscs Acclimation may involve phenotypically plastic responses in behaviour, physiology, or morphology, which can help maintain fitness in a new environment[28,29]. An organism might maintain a specific trait (e.g. growth rate) in a sub-optimal environment compared with present-day conditions because of plasticity in underlying metabolic processes supporting that trait[30]. Whereas reversible acclimation occurs over relatively short periods of several days to months, often within a life stage[32], developmental acclimation occurs when exposure of an organism to a specific environment in its early life stages permanently modifies behaviour or physiology that enhances its performance in that environment later in life[33]
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have