Nematode motility in granular media

Caenorhabditis elegans—an optically transparent nematode—are extensively used as a model organism to explore questions in genetics, developmental biology, and neurobiology. Many of these studies identify the behavioral traits of worms by observing their locomotory patterns. While in their natural settings these worms navigate complex three-dimensional, disordered environments such as soft soil, rotten fruit, and plant stem, most of our understanding of their locomotion comes from studying them on soft two-dimensional surfaces or inside homogeneous liquid media. In this study, we aim to address how worms navigate through a three-dimensional, granular medium—much similar to their natural habitat. We have designed a transparent, self-healing granular material by packing micron-scale hydrogel particles to mimic the natural habitat of nematodes. Through direct visualization of nematode locomotion inside these granular microenvironments, we are exploring how the stiffness of these 3D media affects worm motility. We will present how worms smoothly alter their motility pattern in different granular environments.