Predator-prey interactions of planktonic protists are fundamental to plankton dynamics and include prey selection, detection, and capture as well as predator detection and avoidance. Propulsive, morphology-specific behaviors modulate these interactions and therefore bloom dynamics. Here, interactions between the mixotrophic, harmful algal bloom (HAB) dinoflagellate Dinophysis acuminata and its ciliate prey Mesodinium rubrum were investigated through quantitative microvideography using a high-speed microscale imaging system (HSMIS). The dinoflagellate D. acuminata is shown to detect its M. rubrum prey via chemoreception while M. rubrum is alerted to D. acuminata via mechanoreception at much shorter distances (89 ± 39 μm versus 41 ± 32 μm). On detection, D. acuminata approaches M. rubrum with reduced speed. The ciliate M. rubrum responds through escape jumps that are long enough to detach its chemical trail from its surface, thereby disorienting the predator. To prevail, D. acuminata uses capture filaments and/or releases mucus to slow and eventually immobilize M. rubrum cells for easier capture. Mechanistically, results support the notion that the desmokont flagellar arrangement of D. acuminata lends itself to phagotrophy. In particular, the longitudinal flagellum plays a dominant role in generating thrust for the cell to swim forward, while at other times, it beats to supply a tethering or anchoring force to aid the generation of a posteriorly-directed, cone-shaped scanning current by the transverse flagellum. The latter is strategically positioned to generate flow for enhanced chemoreception and hydrodynamic camouflage, such that D. acuminata can detect and stealthily approach resting M. rubrum cells in the water column.

浮游生物的捕食者与猎物之间的相互作用是浮游生物动力学的基础，包括猎物的选择，检测和捕获以及捕食者的检测和回避。推进，特定形态的行为调节了这些相互作用，并因此引发了动态变化。在这里，通过使用高速微尺度成像系统（HSMIS）进行定量微影像学研究，研究了混合营养，有害藻华（HAB）鞭毛鞭毛藻（Dinoflagellate acuminata）及其纤毛猎物中型红球藻之间的相互作用。示鞭毛的D. acuminata通过化学感受器检测到了红毛丹螺的猎物，而M. rubrum被警觉到了D. acuminata通过机械感受距离更短（89±39μm对41±32μm）。在检测时，尖锐湿疣（D. acuminata）以降低的速度接近红毛丹（M. rubrum）。纤毛的红孢杆菌通过逃逸跳跃做出反应，逃逸跳跃的时间足以将其化学痕迹从其表面分离，从而使掠食者迷失方向。占优势的是，尖锐湿疣（D. acuminata）使用捕获丝和/或释放粘液来减缓并最终固定红血球菌细胞，以便于捕获。从机理上讲，结果支持D. acuminata的desmokont鞭毛排列的观点使自己趋于吞噬。特别是，纵向鞭毛在为细胞向前游动产生推力中起主要作用，而在其他时候，它会跳动以提供束缚力或锚定力，从而有助于产生后向锥形扫描电流。横向鞭毛。后者的位置具有战略意义，可以产生流动来增强化学感受和流体动力伪装，从而使D. acuminata能够检测并隐匿地接近水柱中的静息红麻杆菌细胞。