Efficient mate finding in planktonic copepods swimming in turbulence

Area of Science:

• Marine Biology
• Fluid Dynamics
• Zooplankton Ecology

Background:

• Zooplankton inhabit dynamic aquatic environments where turbulence may impede their locomotion and sensory behaviors.
• Understanding how turbulence affects fundamental zooplankton behaviors, such as mate-finding, is crucial for their ecological success.

Purpose of the Study:

• To investigate how turbulence influences mate-finding success in calanoid copepods.
• To quantify the ability of copepods to overcome physical constraints and olfactory impairment caused by turbulence for reproduction.

Main Methods:

• Simultaneous reconstruction of flow tracer and calanoid copepod trajectories.
• Quantification of encounter rates and mating success under varying turbulence levels.
• Modeling of organism motion and turbulent velocity to determine clearance rates.

Main Results:

• Copepods achieve high encounter rates in turbulent flows due to combined advection and active swimming.
• Males effectively convert encounters into mating opportunities through directed movement within the perception radius.
• Turbulence does not lead to preferential concentration; collision kernel is accurately modeled by clearance rate.

Conclusions:

• A coupled behavioral and physical mechanism allows copepods to reproduce effectively in turbulent environments.
• Advection and vigorous swimming are key factors in enhancing copepod encounter rates.
• The study provides insights into zooplankton reproductive strategies in dynamic aquatic habitats.