Long-Term Tracking of Free-Swimming Paramecium caudatum in Viscous Media Using a Curved Sample Chamber

Abstract

It is technically difficult to acquire large-field images under the complexity and cost restrictions of a diagnostic and instant field research purpose. The goal of the introduced large-field imaging system is to achieve a tolerable resolution for detecting microscale particles or objects in the entire image field without the field-curvature effect, while maintaining a cost-effective procedure and simple design. To use a single commercial lens for imaging a large field, the design attempts to fabricate a curved microfluidic chamber. This imaging technique improves the field curvature and distortion at an acceptable level of particle detection. This study examines Paramecium caudatum microswimmers to track their motion dynamics in different viscous media with imaging techniques. In addition, the study found that the average speed for P. caudatum was 60 µm/s, with a standard deviation of ±12 µm/s from microscopic imaging of the original medium of the sample, which leads to a variation of 20% from the average measurement. In contrast, from large-field imaging, the average speeds of P. caudatum were 63 µm/s and 68 µm/s in the flat and curved chambers, respectively, with the same medium viscosity. Furthermore, the standard deviations that were observed were ±7 µm/s and ±4 µm/s and the variations from the average speed were calculated as 11% and 5.8% for the flat and curved chambers, respectively. The proposed methodology can be applied to measure the locomotion of the microswimmer at small scales with high precision.

Cellular and molecular mechanisms of photoreceptor tuning for prey capture in larval zebrafish

“…S1a,c). We next computed a series of random-walk stimulus paths across this array by an assumed bright 2˚ target moving at an average speed of 100˚/s and with approximately naturalistic turning behaviour (Jung et al, 2014;Shourav and Kim, 2017). This simulation confirmed our previous calculation that a single such target almost never (<0.1% of the time) covers two UV-cones at a time (Fig.…”

Fovea-like Photoreceptor Specializations Underlie Single UV Cone Driven Prey-Capture Behavior in Zebrafish

“…Figures 2 A, 2C, S1 A, and S1C). We next computed a series of random-walk stimulus paths across this array by an assumed bright 2° target moving at an average speed of 100°/s and with approximately naturalistic turning behavior ( Jung et al., 2014 , Shourav and Kim, 2017 ). This simulation confirmed our previous calculation that a single such target almost never (<0.1% of the time) covers two UV cones at a time ( Figure 5 B).…”