Startle response behaviours are important in predator avoidance and escape for a wide array of animals. For many marine invertebrates, however, startle response behaviours are understudied, and the effects of global change stressors on these responses are unknown. We exposed two size classes of blue mussels (Mytilus edulis × trossulus) to different combinations of temperature (15 and 19 °C) and pH (8.2 and 7.5 pH_T) for 3 months and subsequently measured individual time to open following a tactile predator cue (i.e. startle response time) over a series of four consecutive trials. Time to open was highly repeatable in the short term and decreased linearly across the four trials. Individuals from the larger size class had a shorter time to open than their smaller-sized counterparts. High temperature increased time to open compared to low temperature, while pH had no effect. These results suggest that bivalve time to open is repeatable, related to relative vulnerability to predation and affected by temperature. Given that increased closure times impact feeding and respiration, the effect of temperature on closure duration may play a role in the sensitivity to ocean warming in this species and contribute to ecosystem level effects.

惊吓的反应行为对于避免捕食和逃逸各种动物很重要。然而，对于许多海洋无脊椎动物而言，人们对惊吓反应行为的研究不足，而且全球变化压力源对这些反应的影响尚不清楚。我们将两种大小等级的蓝贻贝（Mytilus edulis  ×  trossulus）暴露于温度（15和19°C）和pH（8.2和7.5 pH _T），持续3个月，随后在一系列四次连续试验中，测量了触觉捕食者提示后打开的个人时间（即惊吓反应时间）。打开时间在短期内可高度重复，并且在四项试验中呈线性下降。大型班级的人比小型班级的人拥有更短的开放时间。与低温相比，高温增加了打开时间，而pH值则没有影响。这些结果表明，双壳类动物的开放时间是可重复的，这与捕食相对脆弱性有关，并且受温度影响。考虑到封闭时间的增加会影响进食和呼吸，温度对封闭时间的影响可能会影响该物种对海洋变暖的敏感性，并有助于生态系统的影响。