Meeting Abstract

P2-214  Friday, Jan. 5 15:30 - 17:30  Single Versus Group Feeding Patterns in Vorticella convalleria BAXTER, CA*; PEPPER, RE; University of Puget Sound; University of Puget Sound cbbaxter@pugetsound.edu

Microscopic sessile suspension feeders (MSSFs) are single-celled eukaryotes that live in aquatic environments attached to surfaces. They play a pivotal role in carbon cycling, filter 10-25% of coastal surface water each day, and can remove significant amounts of heavy metals from industrial wastewaters. MSSFs feed on bacteria and debris by creating a fluid flow that varies at different cell body orientations to the surface. When MSSFs feed with their body at an angle to the surface, they filter four times more water than if perpendicular. Previous research has observed that single MSSFs vary this cell body orientation, oscillating angle over time with a consistent pattern. It is unknown why they feed with this pattern, but it is likely important in determining the amount of food intake. Consequently, understanding this oscillating feeding pattern is critical for understanding the impact of MSSF feeding on the carbon cycle. Vorticella, a common MSSF, live both singly and in groups; it is possible that different motion patterns may be advantageous for feeding in groups versus alone. Using cultured Vorticella, we video recorded either single or paired Vorticella under the microscope to determine their orientation relative to the surface of attachment. Orientation was described by finding θ, the polar angle and φ, the azimuthal angle. Motion patterns were compared between single and paired Vorticella by comparing several parameters, including amplitude and frequency of oscillation and average angle for both θ and φ. Many attributes of motion were similar between paired and single Vorticella; however, the paired Vorticella exhibited bigger, slower motion in φ and a slower motion with the same amplitude in θ compared to single Vorticella. This opens up the question of whether this slower, larger motion of paired Vorticella leads to improved nutrient uptake when Vorticella are in close proximity to each other.