Mirza R S, Chivers D P, Godin J G
Department of Biological Sciences, University of Maine, Orono 04469-5751, USA.
J Chem Ecol. 2001 Sep;27(9):1775-85. doi: 10.1023/a:1010404624556.
Brook charr (Salvelinus fontinalis) lay their eggs in gravel nests called redds. The nests are not defended for extended periods and the eggs and young may be subject to predation from predators that travel through the substrate into the redd. In this study we tested whether long-term exposure of brook charr eggs to chemical cues from predatory sculpins (Cottus cognatus) resulted in an adaptive shift in the timing of emergence of charr alevins from artificial redds. We reared brook charr eggs in the presence of chemical cues from sculpins fed brook charr eggs, sculpins fed brine shrimp, and a well water control. Significantly more alevins emerged during the first week of the emergence period when exposed to chemical cues from sculpins fed eggs than from cues from sculpins fed brine shrimp or from well water. Alevins that emerged sooner were smaller and possessed larger yolk sacs than alevins that emerged later in the emergence period. Our results suggest that alevins that emerge sooner may escape predation in the redd, but may pay a cost in being under-developed upon emergence into the open water of the stream or lake.
溪红点鲑（Salvelinus fontinalis）在称为产卵坑的砾石巢穴中产卵。这些巢穴不会长时间受到保护，鱼卵和幼鱼可能会受到通过基质进入产卵坑的捕食者的捕食。在这项研究中，我们测试了溪红点鲑鱼卵长期暴露于来自捕食性杜父鱼（Cottus cognatus）的化学信号是否会导致溪红点鲑仔鱼从人工产卵坑中出现的时间发生适应性变化。我们在喂食溪红点鲑鱼卵的杜父鱼、喂食盐水虾的杜父鱼的化学信号以及井水对照的存在下饲养溪红点鲑鱼卵。与暴露于喂食盐水虾的杜父鱼的信号或井水相比，当暴露于喂食鱼卵的杜父鱼的化学信号时，在出现期的第一周出现的仔鱼明显更多。较早出现的仔鱼比在出现期后期出现的仔鱼体型更小，卵黄囊更大。我们的结果表明，较早出现的仔鱼可能会在产卵坑中逃脱捕食，但在进入溪流或湖泊的开阔水域时可能会因发育不全而付出代价。
