Chiussi Roberto, Diaz Humberto
Centro de Ecologia, Instituto Venezolano de Investigaciones Cientificas, Caracas, Venezuela.
J Chem Ecol. 2002 Sep;28(9):1787-96. doi: 10.1023/a:1020561101616.
Behavioral responses of the fiddler crab Uca cumulanta to flat geometric shapes mimicking natural objects were measured in a circular arena by using zonal recovery as a behavioral measurement. Crabs were tested either in presence or absence of odors from two common predator species, the blue crab Callinectes sapidus, and the pufferfish Sphoeroides testudineus. The study tested the hypothesis that U. cumulanta have different behavioral responses to visual cues in the presence of chemical cues associated with predators. Escape direction tests demonstrated that U. cumulanta is able to show zonal recovery behavior based upon astronomical references. When tested in water lacking predator odor, crabs failed to exhibit a consistent orientation if a single silhouette target was interposed in the landward direction. However, when animals were tested in different predator odor concentrations, an orientation response was obtained at 10 and 20 g/liter/hr blue crab odorand 10 g/liter/hr pufferfish odor, demonstrating U. cumulanta ability to detect the potential presence of its natural predators by this odor. Thus, the hypothesis was supported, and the results suggest that behavioral responses to chemical and visual cues are involved in predator avoidance.
通过使用区域恢复作为行为测量指标，在圆形场地中测量了仿穴小蟹（Uca cumulanta）对模仿自然物体的扁平几何形状的行为反应。在有或没有两种常见捕食者物种气味的情况下对螃蟹进行测试，这两种捕食者分别是青蟹（Callinectes sapidus）和河豚（Sphoeroides testudineus）。该研究检验了这样一个假设：在存在与捕食者相关的化学线索的情况下，仿穴小蟹对视觉线索有不同的行为反应。逃避方向测试表明，仿穴小蟹能够根据天文参考显示区域恢复行为。当在没有捕食者气味的水中进行测试时，如果在向陆地方向插入单个轮廓目标，螃蟹无法表现出一致的方向。然而，当在不同捕食者气味浓度下对动物进行测试时，在10和20克/升/小时的青蟹气味以及10克/升/小时的河豚气味下获得了方向反应，这表明仿穴小蟹能够通过这种气味检测到其天然捕食者的潜在存在。因此，该假设得到了支持，结果表明对化学和视觉线索的行为反应参与了捕食者回避。
