Plankton reach new heights in effort to avoid predators

Area of Science:

• Marine Biology
• Animal Behavior
• Ecology

Background:

• The neuston (air-water interface) is a crucial but understudied marine environment for predator-prey interactions.
• Copepods typically use underwater escape jumps, but viscous forces limit effectiveness in their low-Reynolds-number environment.

Purpose of the Study:

• To investigate novel anti-predator behaviors in neustonic copepods.
• To analyze the kinematics and effectiveness of aerial escapes in predator avoidance.

Main Methods:

• Field recordings of natural predator-prey interactions.
• High-speed laboratory recordings of copepod escape behaviors.
• Kinematic analysis and energetic cost estimation of aerial vs. underwater escapes.

Main Results:

• Two neustonic copepod species were observed to frequently exit the water surface to evade predators.
• Aerial escapes allowed copepods to travel significantly further than underwater escapes, despite substantial kinetic energy loss.
• This aerial behavior effectively removes copepods from the visual range of subsurface-feeding predators.

Conclusions:

• Neustonic copepods possess a unique aerial escape strategy as an effective anti-predator defense.
• This behavior enhances survival against visual predators in the marine surface environment.
• Findings offer new insights into trophic dynamics within the neustonic zone.