QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

This Article Full Text (PDF) References Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Crawford, J. D. Articles by Huang, X. Search for Related Content PubMed PubMed Citation Articles by Crawford, J. D. Articles by Huang, X. Social Bookmarking                         What's this?

Journal of Experimental Biology, Vol 202, Issue 10 1417-1426, Copyright © 1999 by Company of Biologists

JOURNAL ARTICLES

Communication signals and sound production mechanisms of mormyrid electric fish

JD Crawford and X Huang
Department of Psychology, University of Pennsylvania, Philadelphia, PA 19104, USA. jud@psych.upenn.edu

The African weakly electric fishes Pollimyrus isidori and Pollimyrus adspersus (Mormyridae) produce elaborate acoustic displays during social communication in addition to their electric organ discharges (EODs). In this paper, we provide new data on the EODs of these sound-producing mormyrids and on the mechanisms they use to generate species-typical sounds. Although it is known that the EODs are usually species-specific and sexually dimorphic, the EODs of closely related sound-producing mormyrids have not previously been compared. The data presented demonstrate that there is a clear sexual dimorphism in the EOD waveform of P. isidori. Females have a multi-phasic EOD that is more complex than the male's biphasic EOD. In this respect, P. isidori is similar to its more thoroughly studied congener P. adspersus, which has a sexually dimorphic EOD. The new data also reveal that the EODs of these two species are distinct, thus showing for the first time that species-specificity in EODs is characteristic of these fishes, which also generate species-specific courtship sounds. The sound-generating mechanism is based on a drumming muscle coupled to the swimbladder. Transverse sections through decalcified male and female P. adspersus revealed a muscle that envelops the caudal pole of the swimbladder and that is composed of dorso-ventrally oriented fibers. The muscle is five times larger in males (14.5+/-4.4 microl, mean +/- s.d.) than in females (3.2+/-1.8 microl). The fibers are also of significantly larger diameter in males than in females. Males generate courtship sounds and females do not. The function of the swimbladder muscle was tested using behavioral experiments. Male P. adspersus normally produce acoustic courtship displays when presented with female-like electrical stimuli. However, local anesthesia of the swimbladder muscle muted males. In control trials, males continued to produce sounds after injection of either lidocaine in the trunk muscles or saline in the swimbladder muscles.
CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?

This article has been cited by other articles:

				H. H. Zakon, Y. Lu, D. J. Zwickl, and D. M. Hillis Sodium channel genes and the evolution of diversity in communication signals of electric fishes: Convergent molecular evolution PNAS, March 7, 2006; 103(10): 3675 - 3680. [Abstract] [Full Text] [PDF]

				L. Fletcher and J. Crawford Acoustic detection by sound-producing fishes (Mormyridae): the role of gas-filled tympanic bladders J. Exp. Biol., January 1, 2001; 204(2): 175 - 183. [Abstract] [PDF]