Groupe de Recherche sur les Ecosystèmes Aquatiques, Département de chimie-biologie, Université du Québec à Trois-Rivières, C.P. 500, Trois-Rivières (Québec), G9A 5H7 Canada.
J Fish Biol. 2009 May;74(7):1371-82. doi: 10.1111/j.1095-8649.2009.02183.x.
This study investigated the relationship between spatial variations in predation risk and abundance of northern redbelly dace Phoxinus eos at both macroscale (littoral v. pelagic zones) and microscale (structured v. open water habitats in the littoral zone) of Canadian Shield lakes. Minnow traps were placed in both structured and open water habitats in the littoral zone of 13 Canadian Shield lakes, and estimates of the relative predation risk of P. eos in both the pelagic and the littoral zones were obtained from tethering experiments. Results showed that (1) the mean abundance of P. eos in the littoral zone was positively correlated with the relative predation risk in the pelagic zone, (2) P. eos preferentially used structured over open water habitats in the littoral zone and (3) this preference was not related to the relative predation risk in the littoral zone but decreased as the relative predation risk increased in the pelagic zone. At the lake level, these results support the hypothesis that P. eos enter the littoral zone to avoid pelagic piscivores. At the littoral zone level, the results do not necessarily contradict the widely accepted view that P. eos preferentially use structured over open habitats to reduce their predation risk, but suggest that flexibility in antipredator tactics (e.g. shelter use v. shoaling) could explain the spatial distribution of P. eos between structured and open water habitats.
本研究调查了加拿大盾状湖的宏尺度（沿岸区与敞水区）和微尺度（沿岸区的结构生境与开阔水区）上捕食风险的空间变化与北方红腹鱥 Phoxinus eos 丰度之间的关系。在 13 个加拿大盾状湖的沿岸区的结构生境和开阔水区中放置了小鱼网，通过系绳实验获得了 P. eos 在敞水区和沿岸区的相对捕食风险的估计。结果表明：(1) 沿岸区 P. eos 的平均丰度与敞水区的相对捕食风险呈正相关；(2) P. eos 优先选择沿岸区的结构生境而非开阔水区；(3) 这种偏好与沿岸区的相对捕食风险无关，但随着敞水区的相对捕食风险增加而减少。在湖泊水平上，这些结果支持 P. eos 进入沿岸区以避免敞水区的食鱼动物捕食的假设。在沿岸区水平上，这些结果不一定与广泛接受的观点相矛盾，即 P. eos 优先选择结构生境而非开阔生境以降低捕食风险，但表明在捕食者回避策略上的灵活性（例如，利用遮蔽物而不是集群）可以解释 P. eos 在结构生境与开阔水区之间的空间分布。
