The mechanisms of filter feeding on oil droplets: Theoretical considerations

Daphnia-inspired dynamic slippery chemically bonded liquid surface for the active prevention of covalently attached foulant adhesion

“…32,33 Meanwhile, particles are captured near the end of the filtering setae, and then are pushed slowly toward the food groove. 34,35 Some particles occasionally stick onto one of the setae. Instead of simply relying on a hierarchical micro-/ nanostructured topography or smooth lubricating layer, Daphnia possess a set of long setae to dislodge them through combing or repelling actions of the postabdominal claw, acting by itself as a sweeper.…”

Oil Droplet Capture and Ingestion by Filter-Feeding Sabellid and Serpulid Polychaetes

“…These interactions between a particle in water and a filter include i) direct interception, ii) inertial interactions, iii) gravitational deposition, iv) diffusional deposition, and v) sieving. Extending this theory to oil droplet in water and filter fiber interactions, Mehrabian et al (2018) introduce the role of different parameters including oil-to-water viscosity ratio, oil-water interfacial tension, oil-water density difference, and the wettability of the fiber on the success of oil droplet capture and detachment. Wettability is the affinity of one fluid (oil) to adhere to and spread on a solid surface in the presence of another immiscible fluid (water).…”

“…Wettability is the affinity of one fluid (oil) to adhere to and spread on a solid surface in the presence of another immiscible fluid (water). It is governed by the texture and surface chemistry of the solid surface (Mehrabian et al, 2018;Letendre and Cameron, 2022). Experimental tests of this theory include investigating oil droplet capture by Daphnia and barnacles at different Reynolds numbers (Letendre and Cameron, 2022), the role of droplet size and viscosity on capture using copepods and barnacles (Letendre et al, 2020), and the role of surfactants in droplet capture and loss by Daphnia and copepods (Almeda et al, 2014;Letendre et al, 2023).…”

“…At low Re, density and viscosity are important variable for oil droplet capture by fibers. According to theory, neutrally buoyant and small droplets will be preferentially captured (Mehrabian et al, 2018). If the oil is less dense than water, then gravitational forces will move the oil to the top (creaming), and when the oil is heavier than water, the oil will move downwards (sedimentation).…”

“…Oil viscosity is generally greater than water viscosity. Therefore, all parameters being equal, a less viscous oil droplet has higher chance of being captured by a filter feeder compared to a higher viscous oil droplet through inertial interaction and gravitation deposition (Mehrabian et al, 2018). This study is significant to understand the physics of oil droplet capture, the behavior of animals in response to oil emulsions, the bioaccumulation and trophic transfer of oils and because it informs oil spill remediation strategies.…”