|
|
|
|||
| Home Help Feedback Subscriptions Archive Search Table of Contents | ||||
Aquatic turning performance by the whirligig beetle: constraints on maneuverability by a rigid biological system
1 Department of Biology, West Chester University, West Chester, PA 19383,
USA
2 Department of Physics, West Chester University, West Chester, PA 19383,
USA
* Author for correspondence (e-mail: ffish{at}wcupa.edu)
Accepted 24 February 2003
Turning performance is constrained by morphology, where the flexibility of the body and the mobility and position of the control surfaces determine the level of performance. The use of paddling appendages in conjunction with the rigid bodies of aquatic arthropods could potentially limit their turning performance. Whirligig beetles (Coleoptera: Gyrinidae) are rigid-bodied, but these aquatic insects can swim rapidly in circular patterns. Turning performance of swimming whirligig beetles (Dineutes horni) was assessed by videotaping beetles in a small (115 mm diameter) arena at 500 frames s1 and 1000 frames s1. Curved trajectories were executed as continuous powered turns. Asymmetrical paddling of the outboard legs was used to power the turn. Turns were produced also by abduction of the inboard elytra and vectored thrust generated from sculling of the wing at 47.14 Hz. The abducted elytra increased drag and acted as a pivot. Swimming speeds varied from 0.06 m s1 to 0.55 m s1 (4.744.5 L s1). Relative minimum radius was 24%of body length. Maximum rate of turn was 4428 degrees s1 with maximum centripetal acceleration of 2.86 g. Turning radius was weakly associated with swimming velocity, although minimum values of the radius showed no correlation with velocity. Turning rate was also related indirectly to radius and directly to centripetal acceleration. Compared to vertebrates with flexible bodies, the relative turning radius of whirligig beetles is constrained by a rigid body and use of drag-based propulsive mechanisms. However, these mechanisms permit continuous turning, and the size of the beetle permits higher turn rates with lower centripetal accelerations.
Key words: whirligig beetle, Dineutes, maneuverability, turning rate, flexibility
![]()
CiteULike
Complore
Connotea
Del.icio.us
Digg
Reddit
Technorati
Twitter What's this?
This article has been cited by other articles:
![]() |
J. Voise and J. Casas The management of fluid and wave resistances by whirligig beetles J R Soc Interface, August 19, 2009; (2009) rsif.2009.0210v2. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. Ribak, D. Weihs, and Z. Arad Consequences of buoyancy to the maneuvering capabilities of a foot-propelled aquatic predator, the great cormorant (Phalcrocorax carbo sinensis) J. Exp. Biol., September 15, 2008; 211(18): 3009 - 3019. [Abstract] [Full Text] [PDF] |
||||
![]() |
W. L. Romey and E. Galbraith Optimal group positioning after a predator attack: the influence of speed, sex, and satiation within mobile whirligig swarms Behav. Ecol., March 1, 2008; 19(2): 338 - 343. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. Rivera, A. R. V. Rivera, E. E. Dougherty, and R. W. Blob Aquatic turning performance of painted turtles (Chrysemys picta) and functional consequences of a rigid body design J. Exp. Biol., November 1, 2006; 209(21): 4203 - 4213. [Abstract] [Full Text] [PDF] |
||||