Publication
How does environment influence fighting? The effects of tidal flow on resource value and fighting costs in sea anemones
Publisher:
The Royal Society
Date:
05-2017
DOI:
10.1098/RSBL.2017.0011
Abstract: An animal's decision to enter into a fight depends on the interaction between perceived resource value (V) and fighting costs (C). Both could be altered by predictable environmental fluctuations. For intertidal marine animals, such as the sea anemone Actinia equina , exposure to high flow during the tidal cycle may increase V by bringing more food. It may also increase C via energy expenditure needed to attach to the substrate. We asked whether simulated tidal cycles would alter decisions in fighting A. equina . We exposed some in iduals to still water and others to simulated tidal cycles. To gain insights into V, we measured their startle responses before and after exposure to the treatments, before staging dyadic fights. In iduals exposed to flow present shorter startle responses, suggesting that flowing water indicates high V compared with still water. A higher probability of winning against no-flow in iduals and longer contests between flow in iduals suggests that increased V increases persistence. However, encounters between flow in iduals were less likely to escalate, suggesting that C is not directly related to V. Therefore, predictable environmental cycles alter V and C, but in complex ways.