Related Experiment Video
Updated: Apr 24, 2026
09:16
High-resolution Patterning Using Two Modes of Electrohydrodynamic Jet: Drop on Demand and Near-field Electrospinning
Published on: July 10, 2018
9.5K
Archerfish actively control the hydrodynamics of their jets
Peggy Gerullis1, Stefan Schuster1
1Department of Animal Physiology, University of Bayreuth, 95440 Bayreuth, Germany.
Current Biology : CB
|September 10, 2014
Summary
Archerfish can actively control water jet hydrodynamics to hit targets at varying distances. This involves adjusting mouth opening dynamics, similar to human throwing, potentially driving cognitive evolution.
Area of Science:
- Animal Behavior
- Fluid Dynamics
- Evolutionary Biology
Background:
- Tool-using animals typically do not adapt water jet hydrodynamics.
- Archerfish are known for water jet hunting but previously thought incapable of active jet control.
Purpose of the Study:
- To investigate archerfish's ability to control water jet hydrodynamics.
- To explore how fish adjust jet properties for targets at different distances.
Main Methods:
- Trained archerfish to shoot water jets at targets.
- Monitored jet production and propagation over extended ranges.
- Analyzed mouth opening dynamics during jet firing.
Main Results:
- Water jets traveling farther were observed to be more stable.
- Jet formation time was adjusted for maximal focusing before impact.
- Archerfish modulated mouth opening dynamics, a novel mechanism for water nozzles.
Conclusions:
- Archerfish demonstrate sophisticated control over water jet hydrodynamics.
- These abilities parallel human throwing, suggesting a similar evolutionary driver for cognitive skills.
- The findings challenge previous assumptions about animal capabilities in fluid manipulation.
Related Concept Videos
01:14Free Jet
737
Free jets describe the flow of liquid exiting a reservoir through an opening into the atmosphere without resistance. The velocity (v) of the liquid jet is derived using Bernoulli's principle and expressed as:
737
01:04Hydrostatic Pressure Force on a Plane Surface
3.1K
When a plane surface is submerged in a fluid, hydrostatic forces develop on the surface due to the fluid's pressure. For horizontal surfaces, the pressure exerted by the fluid is uniform because the depth remains constant. The resultant force is determined by the pressure at the given depth multiplied by the area of the surface, and it acts through the centroid of the surface. For vertical surfaces, the pressure varies with depth, increasing as the distance from the fluid's free surface...
3.1K
01:17Accelerating Fluids
2.2K
When a fluid is in constant acceleration, the pressure and buoyant force equations are modified. Suppose a beaker is placed in an elevator accelerating upward with a constant acceleration, a. In the beaker, assume there is a thin cylinder of height h with an infinitesimal cross-sectional area, ΔS.
The motion of the liquid within this infinitesimal cylinder is considered to obtain the pressure difference. Three vertical forces act on this liquid:
The motion of the liquid within this infinitesimal cylinder is considered to obtain the pressure difference. Three vertical forces act on this liquid:
2.2K
01:04Hydrostatic Pressure Force on a Curved Surface
1.5K
Hydrostatic pressure on curved surfaces is a fundamental concept in fluid mechanics with broad applications in the civil engineering field. When fluid is in contact with a curved surface, as in a reservoir, dam, or storage tank, it exerts pressure that varies in magnitude and direction along the curved surface. To assess the total hydrostatic force exerted by the fluid on a curved structure, engineers typically isolate the fluid volume adjacent to the surface and analyze the forces acting on...
1.5K
01:27Steady Flow of a Fluid Stream
955
Consider a control volume, such as a pipe with solid boundaries, through which fluid flows and changes direction due to the impulse exerted by the resulting force from the pipe walls. In steady flow, the mass of fluid entering the control volume at a given time, t, with velocity v1, is equal to the mass leaving after infinitesimal time dt, with velocity v2.
During this process, the momentum of the fluid within the control volume remains constant over the time interval dt. By applying the...
During this process, the momentum of the fluid within the control volume remains constant over the time interval dt. By applying the...
955
01:14Fluid Pressure
1.3K
In mechanical engineering, fluid pressure plays a critical role in designing systems that utilize liquid flow, such as hydraulic systems, pumps, and valves. When designing these systems, engineers must ensure they can withstand the forces created by fluid pressure to avoid damage or failure.
According to Pascal's law, a fluid at rest will generate equal pressure in all directions. This pressure is measured as a force per unit area, and its magnitude depends on the fluid's specific...
According to Pascal's law, a fluid at rest will generate equal pressure in all directions. This pressure is measured as a force per unit area, and its magnitude depends on the fluid's specific...
1.3K