Related Experiment Video
Updated: May 22, 2026
07:03
The Ingestion of Fluorescent, Magnetic Nanoparticles for Determining Fluid-uptake Abilities in Insects
Published on: December 20, 2017
Localized fluidization burrowing mechanics of Ensis directus
Amos G Winter1, Robin L H Deits, A E Hosoi
1Department of Mechanical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA. awinter@mit.edu
The Journal of Experimental Biology
|May 25, 2012
Summary
Atlantic razor clams burrow deep by fluidizing soil. Their valve motions create a fluid-like soil, significantly reducing burrowing energy and enabling depths impossible in static soil.
Area of Science:
- Marine Biology
- Biophysics
- Soil Mechanics
Background:
- Atlantic razor clams (Ensis directus) burrow to depths exceeding 70 cm.
- Muscle strength suggests they can only burrow a few centimeters in static soil.
Purpose of the Study:
- Investigate the mechanism enabling deep burrowing in Ensis directus.
- Determine how razor clams overcome limitations of their muscle strength for burrowing.
Main Methods:
- Utilized a novel visualization system for in situ observation of burrowing.
- Employed particle image velocimetry (PIV) to measure substrate deformations.
- Applied soil and fluid mechanics principles to analyze data.
Main Results:
- Ensis directus uses valve motions to locally fluidize surrounding soil.
- Fluidized soil significantly reduces burrowing drag and energy expenditure.
- Burrowing energy scales linearly with depth in fluidized soil, unlike static soil.
Conclusions:
- Localized soil fluidization is the key mechanism for deep burrowing in Ensis directus.
- This method reduces energy requirements by an order of magnitude.
- The findings challenge previous assumptions about burrowing mechanics in bivalves.
Related Concept Videos
01:18Fluid Movement Between Compartments
The force applied by fluids against a surface, known as hydrostatic pressure, initiates the transfer of fluid among different compartments. Within our blood vessels, the blood's hydrostatic pressure is a result of the heart's pumping action. At the arteriolar end of capillaries, hydrostatic pressure (capillary blood pressure) exceeds the opposing colloid osmotic pressure created primarily by plasma proteins like albumin. This discrepancy in pressure propels plasma and nutrients from the...
01:19Capillarity in Fluid
Capillarity describes the movement of liquid in small spaces without external forces acting on it. The capillarity is driven by surface tension and adhesive interactions between the liquid and surrounding solid surfaces. This effect is often seen in narrow tubes, porous materials, and fine particles.
Surface tension is crucial to capillarity. It results from cohesive forces between liquid molecules at the liquid-air boundary, forming a skin that resists external forces. When the capillary tube...
Surface tension is crucial to capillarity. It results from cohesive forces between liquid molecules at the liquid-air boundary, forming a skin that resists external forces. When the capillary tube...
01:27Types of Fluids
Fluids can be classified into Newtonian and non-Newtonian fluids based on their response to shear stress. Newtonian fluids have a linear relationship between shear stress and the shear strain rate, following Newton's law of viscosity. Their viscosity remains constant regardless of the shear rate, making their behavior predictable and easier to analyze. Common examples include water, air, oil, and gasoline.
In contrast, non-Newtonian fluids do not follow Newton's law of viscosity, and their...
In contrast, non-Newtonian fluids do not follow Newton's law of viscosity, and their...
01:20Characteristics of Fluids
When a force is applied parallel to the top surface of a solid, it resists the applied force due to the internal frictional forces between the layers of the solid known as shearing resistance. However, when the force is removed, the shearing forces restore the original shape of the solid. Other deformation forces also cause temporary changes in shape if the forces are not beyond a threshold magnitude. Solids tend to retain their shape, making the study of their rest and motion easier. Beyond...
01:31Characteristics of Fluids
Fluids differ from solids primarily in their molecular structure and stress response. Solids have tightly packed molecules with strong intermolecular forces, maintaining their shape and resisting deformation. In contrast, fluids have molecules spaced farther apart with weaker forces, allowing them to flow and deform easily.
Fluids, which include both liquids and gases, are substances that deform continuously under shearing stress. For example, water and oil are liquids with molecules that can...
Fluids, which include both liquids and gases, are substances that deform continuously under shearing stress. For example, water and oil are liquids with molecules that can...
01:24Rapidly Varying Flow
Rapidly varying flow (RVF) in open channels is characterized by abrupt changes in flow depth over a short distance, with the rate of depth change relative to distance often approaching unity. These flows are inherently complex due to their transient and multi-dimensional nature, making exact analysis difficult. However, approximate solutions using simplified models provide valuable insights into their behavior.Key Features of Rapidly Varying FlowRVF is commonly observed in scenarios involving...