McLeod Ian M, Rummer Jodie L, Clark Timothy D, Jones Geoffrey P, McCormick Mark I, Wenger Amelia S, Munday Philip L
AIMS@JCU and Australian Institute of Marine Science, Townsville, QLD 4810, Australia; School of Marine and Tropical Biology, James Cook University, Townsville, QLD 4811, Australia; ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD 4811, Australia.
ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD 4811, Australia.
Conserv Physiol. 2013 Oct 1;1(1):cot024. doi: 10.1093/conphys/cot024. eCollection 2013.
Climate-change models predict that tropical ocean temperatures will increase by 2-3°C this century and affect plankton communities that are food for marine fish larvae. Both temperature and food supply can influence development time, growth, and metabolism of marine fishes, particularly during larval stages. However, little is known of the relative importance and potential interacting effects of ocean warming and changes to food supply on the performance of larval fishes. We tested this for larvae of the coral reef anemonefish, Amphiprion percula, in an orthogonal experiment comprising three temperatures and three feeding schedules. Temperatures were chosen to represent present-day summer averages (29.2°C) and end-of-century climate change projections of +1.5°C (30.7°C) and +3°C (32.2°C). Feeding schedules were chosen to represent a reduction in access to food (fed daily, every 2 days, or every 3 days). Overall, larvae took longer to settle at higher temperatures and with less frequent feeding, and there was a significant interaction between these factors. Time to metamorphosis was fastest in the 30.7(o)C and high food availability treatment (10.5 ± 0.2 days) and slowest in the 32.2(o)C and low food availability treatment (15.6 ± 0.5 days; i.e. 50% faster). Fish from the lower feeding regimens had a lower body condition and decreased survivorship to metamorphosis. Routine oxygen consumption rates were highest for fish raised at 32.2°C and fed every third day (162 ± 107 mg O2 kg(-1) h(-1)) and lowest for fish raised at 29.2°C and fed daily (122 ± 101 mg O2 kg(-1) h(-1); i.e. 35% lower). The elevated routine oxygen consumption rate, and therefore greater energy use at higher temperatures, may leave less energy available for growth and development, resulting in the longer time to metamorphosis. Overall, these results suggest that larval fishes will be severely impacted by climate-change scenarios that predict both elevated temperatures and reduced food supply.
气候变化模型预测，热带海洋温度在本世纪将升高2至3摄氏度，这会影响作为海洋鱼类幼体食物的浮游生物群落。温度和食物供应都会影响海洋鱼类的发育时间、生长和新陈代谢，尤其是在幼体阶段。然而，对于海洋变暖以及食物供应变化对幼体鱼类生长表现的相对重要性和潜在交互作用，我们却知之甚少。我们在一项包含三种温度和三种投喂频率的正交实验中，对珊瑚礁小丑鱼（眼斑双锯鱼）的幼体进行了测试。所选温度代表当前夏季平均温度（29.2摄氏度）以及本世纪末气候变化预测的升温1.5摄氏度（30.7摄氏度）和升温3摄氏度（32.2摄氏度）。所选投喂频率代表获取食物机会的减少（每天投喂、每两天投喂一次或每三天投喂一次）。总体而言，幼体在较高温度和投喂频率较低的情况下，需要更长时间才能定居，而且这些因素之间存在显著的交互作用。变态所需时间在30.7摄氏度且食物供应充足的处理组中最快（10.5±0.2天），在32.2摄氏度且食物供应不足的处理组中最慢（15.6±0.5天；即快了50%）。投喂频率较低的组中的鱼身体状况较差，变态时的存活率也较低。常规耗氧率在32.2摄氏度且每三天投喂一次的饲养条件下最高（162±107毫克氧气·千克-1·小时-1），在29.2摄氏度且每天投喂的饲养条件下最低（122±101毫克氧气·千克-1·小时-1；即低35%）。较高温度下常规耗氧率升高，因而能量消耗更大，这可能会使可用于生长和发育的能量减少，导致变态所需时间更长。总体而言，这些结果表明，幼体鱼类将受到预测温度升高和食物供应减少的气候变化情景的严重影响。
