Is acoustic communication a candidate signal for sexual selection in Malawian cichlids?

by Smith, Adam R.

Abstract (Summary)
Dr. Moira van Staaden, Advisor The description and classification of signals under sexual selection is a classical problem in evolutionary biology. This difficulty derives primarily from deficiencies in both the hypothetical framework describing communicative signals and in the empirical methods used to verify hypotheses of sexual selective function. Most currently accepted models of sexual selection operate only under highly specific circumstances and therefore cannot easily be applied to the complex situations surrounding selection and speciation in natural environments. In the following studies, we conducted a series of experiments in order to assess the likelihood that a sensory signal is under active sexual selection, whether by itself or in concert with other complimentary signals. For this purpose, we analyzed acoustic communication in Malawian cichlids, widely recognized as a classic model system for explosive species radiation. By describing both acoustic characteristics and the temporal concordance of visual and acoustic behaviors at multiple phylogenetic levels, we determined that the majority of signal divergence is present at levels consistent with expectations of divergence under sexual selection. Moreover, in situ data from Lake Malawi indicate that acoustic signaling by cichlids is prevalent during times when cichlids undergo courtship. We therefore conclude that acoustic signals are an important part of cichlid sexual signaling, and that contrary to the predominant view, such communication in Malawian cichlids is not entirely restricted to the visual modality. iii Behavior can be as revealing as external morphology in the diagnosis of difficult species, as every naturalist knows. -- Peter Marler, 1977 iv
Bibliographical Information:


School:Bowling Green State University

School Location:USA - Ohio

Source Type:Master's Thesis

Keywords:cichlids communication in sex malawi


Date of Publication:

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