Undergraduate Research

Summers Lab
Friday Harbor Marine Labs
University of Washington

Filter Feeding in Mobulid Rays
Mentor: Misty Paig-Tran

Filter feeding is widespread the aquatic environment, utilized by sponges to fishes to whales. The mechanics of flow and particle separation were thought to be most akin to that of a sieve (ie. straining pasta with a colander). Yet the wide range in filter morphology reveals that animals use a number of methods to entrain and sort particles from the water flow.

One of the largest filter feeding fishes, Manta Rays (and other mobulid rays) have a highly unique filter. Working with Dr. Summers and Dr. Paig-Tran, I designed 3D physical models based on the filter lobes of Manta Rays. Using dye visualization in a flow field we discovered the first evidence that manta rays use a new type of filtration, vortex filtration. By passively manipulating (by way of filter morphology) the flow field, vortices are formed within the filter pore. We hypothesized that these vortices serve to separate and entrain food particles from the engulfed water, and move them towards the esophagus of the animal. Recent work (2013 +) by Dr. Paig Tran and graduate student, Raj Divi (Bolla), have expanded this research and confirmed our original hypothesis!

Check out their research below

Pacific Sandlance Substrate Preference
Mentor: Joseph Bizzarro

The Pacific sand lance (Ammodytes hexapterus) is a an important prey for many fishes, birds, and mammals (including migratory grey whales) in coastal regions of the northern Pacific Ocean. Sand lance bury in the substrate overnight and to avoid predation; the availability of a preferred sediment is important for survival and maintaining healthy populations.