The Indo-West Pacific emperor shrimp, Zenopontonia rex (Kemp, 1922) from the family Palaemonidae, was hitherto known as a peaceful symbiotic crustacean, feeding on very small organisms or detritus and other organic particles trapped in its varied hosts’ mucus. However, at two occasions in Indonesia, Z. rex was observed capturing and subduing relatively large and agile animals, representing completely new observations for the species’ diet and feeding behaviour. In the first case, Z. rex associated with the large chromodorid nudibranch Ceratosoma tenue Abraham, 1876 captured another palaemonid shrimp (Cuapetes sp.), only slightly smaller in size. In the second case, two individuals of Z. rex associated with a sea star, Echinaster luzonicus (Gray, 1840), were seen actively exploring the substrate under the star’s arms and one of them eventually captured and killed a juvenile/post-larval fish, probably a goby (Gobiidae). The second case represents one of the few in situ observations of a caridean shrimp killing a vertebrate.

印度-西太平洋帝王虾Zenopontonia rex (Kemp, 1922) 来自 Palaemonidae 科，迄今为止被称为和平共生甲壳类动物，以非常小的生物或碎屑和其他被困在其不同宿主粘液中的有机颗粒为食。然而，在印度尼西亚有两次，观察到霸王龙捕获和制服相对较大和敏捷的动物，代表了对该物种饮食和摄食行为的全新观察。在第一个案例中，霸王龙与大型染色质裸鳃类动物 Ceratosoma tenue Abraham相关联，1876 年捕获了另一只体型略小的古虾（Cuapetes sp.）。在第二种情况下，Z. rex 的两个个体与海星Echinaster luzonicus (Gray, 1840)相关的海星被看到积极探索海星臂下的底物，其中一个最终捕获并杀死了一条幼鱼/后幼鱼，可能是虾虎鱼 (Gobiidae)。第二个案例是为数不多的对海虾杀死脊椎动物的原位观察之一。