| Timing is everything: coordination of strike kinematics affects the force exerted by suction feeding fish on attached prey. | |
| | |
MedLine Citation:
|
PMID: 17872986 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
During aquatic suction feeding, the predator opens its mouth and rapidly expands its buccal cavity, generating a flow field external to the mouth. The rapid expansion of the buccal cavity produces high fluid velocities and accelerations that extend only a short distance from the mouth (about half of one mouth diameter), and only persist for several milliseconds. Therefore, the predator must precisely time its strike to locate the prey within the narrow region of high flow, during the brief period when flow is at its peak. With flow being the agent for transferring force to the prey, the predator may enhance these forces by producing higher water velocities and faster acceleration at the mouth, but also through increasing the strike's accuracy, i.e. locating the prey closer to the mouth at the instant of peak flow speed. The objectives of this study were to directly measure forces exerted by bluegill Lepomis macrochirus on their prey and to determine how bluegill modify force output. Bluegill were offered ghost shrimp tethered to a load cell that recorded force at 5000 Hz, and feeding sequences were synchronously recorded using 500 Hz video. Peak forces exerted on attached 20 mm shrimp ranged from 0.005 N to 0.506 N. In accordance with the short duration of the strikes (average time to peak gape of approximately 13 ms), the forces recorded were brief (approximately 12 ms from initiation to peak force), and force magnitude declined rapidly after peak force. Statistical analysis indicated that rate of buccal expansion, and prey size, but not strike initiation distance, significantly affected peak force. These observed variables were used with results from flow visualization studies to estimate the flow at the prey's location, which allowed the calculation of drag, pressure gradient force and acceleration reaction force. The relationship between these calculated forces and the measured forces was strong, indicating that the model can be used to estimate forces from strike kinematics. This model was then used to study the effects of strike initiation distance on peak force and on the rate of increasing force. Comparisons of model output to empirical results indicated that bluegill time their strike so as to exert an average of approximately 70% of the peak possible force on the prey, and that the observed strike initiation distance corresponded to the distance that maximized modeled force on an attached prey. Our results highlight the ability of bluegill to produce high forces on their prey, and indicate that precision and visual acuity play important roles in prey acquisition, beyond their recognized role in prey detection. |
| | |
Authors:
|
Roi Holzman; Steven W Day; Peter C Wainwright |
Related Documents
:
|
15234506 - Forces transmitted along human flexor tendons during passive and active movements of th... 20365046 - Random walker in temporally deforming higher-order potential forces observed in a finan... 17961516 - Transcranial magnetic stimulation during voluntary action: directional facilitation of ... 9195266 - Biomechanical study of the grosse-kempf femoral nail. 10647546 - Effect of push frequency on the economy of wheelchair racers. 10643746 - Revised limit cycle oscillator model of human circadian pacemaker. |
Publication Detail:
|
Type: Journal Article; Research Support, U.S. Gov't, Non-P.H.S. |
Journal Detail:
|
Title: The Journal of experimental biology Volume: 210 ISSN: 0022-0949 ISO Abbreviation: J. Exp. Biol. Publication Date: 2007 Oct |
Date Detail:
|
Created Date: 2007-09-17 Completed Date: 2007-12-12 Revised Date: - |
Medline Journal Info:
|
Nlm Unique ID: 0243705 Medline TA: J Exp Biol Country: England |
Other Details:
|
Languages: eng Pagination: 3328-36 Citation Subset: IM |
Affiliation:
|
Section of Evolution and Ecology, University of California, One Shields Avenue, Davis, CA 95616, USA. raholzman@ucdavis.edu |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Animals Biomechanics Feeding Behavior / physiology* Mouth / physiology Perciformes / physiology* Sucking Behavior / physiology* Time Factors |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: The contribution of mineral to the material properties of vertebral cartilage from the smooth-hound ...
Next Document: Orientation towards prey in antlions: efficient use of wave propagation in sand.