|
|
|
|||
| Home Help Feedback Subscriptions Archive Search Table of Contents | ||||
First published online May 30, 2008
Journal of Experimental Biology 211, 1969-1977 (2008)
Published by The Company of Biologists 2008
doi: 10.1242/jeb.016949
Female choice by electric pulse duration: attractiveness of the males' communication signal assessed by female bulldog fish, Marcusenius pongolensis (Mormyridae, Teleostei)
Zoologisches Institut, Universität Regensburg, D-93040 Regensburg, Germany
* Author for correspondence (e-mail: Bernd.Kramer{at}biologie.uni-regensburg.de)
Accepted 1 April 2008
In adult males of the South African weakly electric bulldog fish,
Marcusenius pongolensis, the duration of the electric organ discharge
(EOD) increases with body size over lifetime. Although there is experimental
support for intrasexual selection (male–male competition) having shaped
the males' EOD pulse duration in evolution, nothing is known about intersexual
selection, such as female choice. Playback of 25 natural male EODs of pulse
duration varying from 320 µs (close to the average female value) to 716
µs, to eight female experimental subjects elicited approach, head butts and
circling behaviour. The rate of head butts on the dipole electrode model
increased significantly with stimulus pulse duration in seven out of eight
experimental subjects. In ten experimental female subjects we contrasted the
shortest playback pulse with simultaneous playback of one of four longer ones
(424, 524, 628 and 716 µs). Pooled responses for all experimental subjects
were stronger for the dipole playing back the longer pulse in a pulse pair.
The difference in the number of head butts (
head butts) that were dealt
the two dipoles per 60 s test session increased significantly with the
difference in pulse duration (
pulse duration). The increase followed a
significant linear trend (P<0.0001). Similar results were obtained
for
association time,
circles with head butts, and
circles without head butts. These results suggest that a male's
reproductive success is enhanced by longer, i.e. more attractive EODs, and
that both intra- and intersexual selection must have played a significant role
in shaping the EOD of male M. pongolensis.
Key words: electric organ discharge, sexual selection, sensory exploitation, sensory bias, playback stimulation, electrocommunication, handicap, predation pressure
![]()
CiteULike
Complore
Connotea
Del.icio.us
Digg
Reddit
Technorati
Twitter What's this?