Damage released prey alarm substances or predator odours? Risk assessment by an aquatic oligochaete

摘要: Although the abilities of prey to detect and respond chemical substances associated with a predator have been widely reported, factors promoting evolution responses alarm cues vs. odours are still vague. In this article, we combined field research laboratory experiments explore which substance activity (predator odour, conspecific or heterospecific substances) induces defence in aquatic oligochaete Stylaria lacustris, is vulnerable common littoral predators. The results indicated that predators injure oligochaetes great proportion, up 45% individuals population, were found be damaged. revealed from damselfly larvae feeding on S. lacustris did not induce response oligochaetes. On contrary, detected responded damaged conspecifics alone cladoceran Daphnia magna. We discussed conditions favouring damage released instead lacustris. Our data suggest selection may dependent three factors: (1) non-species-specific predation, (2) divergence food niche different stages (3) complex web multiple