Soft-surface grasping: radular opening in Aplysia californica
| Autor: | Rebekah K. Smoldt, Sisi Lu, Catherine E. Kehl, Hillel J. Chiel, Joey Wu, David M. Neustadter, Richard F. Drushel |
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| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
0106 biological sciences
Physiology 030310 physiology Aquatic Science 010603 evolutionary biology 01 natural sciences 03 medical and health sciences Soft body biomechanics Aplysia Molluscan behavior Animals 14. Life underwater Molecular Biology Ecology Evolution Behavior and Systematics 0303 health sciences Mouth biology Chemistry Feeding Anatomy Feeding Behavior biology.organism_classification Biomechanical Phenomena Insect Science Animal Science and Zoology Research Article |
| Zdroj: | The Journal of Experimental Biology |
| ISSN: | 1477-9145 0022-0949 |
| Popis: | Grasping soft, irregular material is challenging both for animals and robots. The feeding systems of many animals have adapted to this challenge. In particular, the feeding system of the marine mollusk Aplysia californica, a generalist herbivore, allows it to grasp and ingest seaweeds of varying shape, texture and toughness. On the surface of the grasper of A. californica is a structure known as the radula, a thin flexible cartilaginous sheet with fine teeth. Previous in vitro studies suggested that intrinsic muscles, I7, are responsible for opening the radula. Lesioning I7 in vivo does not prevent animals from grasping and ingesting food. New in vitro studies demonstrate that a set of fine muscle fibers on the ventral surface of the radula – the sub-radular fibers (SRFs) – mediate opening movements even if the I7 muscles are absent. Both in vitro and in vivo lesions demonstrate that removing the SRFs leads to profound deficits in radular opening, and significantly reduces feeding efficiency. A theoretical biomechanical analysis of the actions of the SRFs suggests that they induce the radular surface to open around a central crease in the radular surface and to arch the radular surface, allowing it to softly conform to irregular material. A three-dimensional model of the radular surface, based on in vivo observations and magnetic resonance imaging of intact animals, provides support for the biomechanical analysis. These results suggest how a soft grasper can work during feeding, and suggest novel designs for artificial soft graspers. Summary: Newly described muscle fibers control a soft, flexible surface that the marine slug Aplysia californica uses to feed on seaweed, suggesting a novel mechanism for constructing a soft grasping device. |
| Databáze: | OpenAIRE |
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