Predation is an important factor influencing the strength and success of a year class in many prey fishes. Many adaptations, including chemical cues, benefit shoaling groups by informing members of a possible impending predatory threat. Bighead (Hypophthalmichthys nobilis) and silver carps (Hypophthalmichthys molitrix) are widely dispersed invasive fishes that spend much of their first year at a size vulnerable to predation. The objective of this study was to evaluate the fright response of juvenile bighead and silver carps when exposed to alarm cues from conspecific and heterospecific fishes. Groups of carps were exposed to 5 mL of alarm cue from either bighead carp, silver carp, golden shiner (Notemigonus crysoleucas), or fathead minnow (Pimephales promelas). Behavior was recorded before and after the application of the treatment. Our results indicate that both species were unable to recognize chemical alarm cues from North American cypriniforms, yet both were able to recognize conspecific alarm cues. However, the two species of bigheaded carps respond to conspecific chemicals differently. Silver carp increase distance among individuals, whereas bighead carp reduce distance between individuals. Both show a reduction in activity after chemical application. Though both species recognize conspecific alarm cues, bighead carp exhibit similar fright patterns when exposed to alarm chemicals of silver carp, yet no behavioral responses were detected in silver carp when exposed to alarm chemicals of bighead carp. An understanding of fright response in bighead and silver carps aids understanding of predator interactions and ecological roles of these fishes, and can be utilized in population management applications.

捕食是影响许多pre鱼一年生强度和成功的重要因素。通过将可能发生的掠夺性威胁通知成员，使包括化学线索在内的许多改编都有利于暗礁小组。head（Hypophthalmichthys nobilis）和银鲤（Hypophthalmichthys molitrix）是广泛分布的入侵鱼类，第一年的大部分时间都处于容易被捕食的大小。这项研究的目的是评估当暴露于同种和异种鱼的警报提示下时，big鱼和银鲤的惊吓反应。big鱼，big鱼，golden鱼，金光shine（Notemigonus crysoleucas）或黑头min鱼（5头alarm）暴露于5 mL警报提示下。Pimephales promelas）。记录治疗前后的行为。我们的结果表明，这两种物种均无法识别来自北美鲤鱼的化学警报提示，但都能够识别同种警报提示。但是，这两种of鱼对特定化学物质的反应不同。鱼增加个体之间的距离，而big鱼减少个体之间的距离。两者均显示出化学作用后活性降低。尽管两个物种都可以识别同种警报线索，但big鱼暴露于silver鱼警报化学物质中时会表现出相似的惊吓模式，但silver鱼暴露于big鱼警报化学物质中时未检测到行为反应。