Award: OCE-1061182

Mnemiopsis is a small delicate gelatinous predator that lives in coastal waters along the western Atlantic Ocean. Despite its size and delicate structure it is a highly successful predator capable of removing a majority of its prey from the water column. This study investigated how this predator functioned in its natural environment where waters are often highly turbulent. The our work with Mnemiopsis demonstrated from laboratory analysis that Mnemiopsis uses a very slow, laminar feeding current to entrain and transport prey to be captured (Figure 1). This feeding current enables Mnemiopsis to encounter a large volume of water over time and a large number of prey. However, we show that out in nature, where there is background turbulence, that the feeding current of Mnemiopsis is overwhelmed by the turbulence (Figure 2). In response to turbulence we found that the behavior of Mnemiopsis changes its behavior and it speeds up its swimming speed. This has important implications for the ability of Mnemiopsis to effectively capture prey. To investigate if swimming behavior impacted the ablity of Mnemiopsis to feed we looked at how Mnemiopsis caught prey and if that changed with swimming speed. From this study we found that Mnemiopsis does not feed passively (like other jellyfish), instead, it uses sensory capabilities to scan its feeding current for prey. This enhances how well Mnemiopsis captures prey and enables it to feed just as effectively whether it is hovering or swimming. As a result of its feeding strategy, which includes generating a slow and steady feeding current and sensory scanning the feeding current for prey, Mnemiopsis is capable of feeding in a range of turbulent environments and can have a greater predatory impact than other jellyfish predators (Figure 3). Last Modified: 04/13/2015 Submitted by: Sean P Colin