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Please use this identifier to cite or link to this item: http://hdl.handle.net/1807/30525

Title: Molecular Phylogenetics of the Neotropical Electric Knifefish Genus Gymnotus (Gymnotidae, Teleostei): Biogeography and Signal Evolution of the Trans-Andean Species
Authors: Brochu, Kristen
Advisor: Lovejoy, Nathan
Department: Ecology and Evolutionary Biology
Keywords: Gymnotiformes
signal evolution
molecular phylogenetics
Neotropical fish
Issue Date: 5-Dec-2011
Abstract: Gymnotus, the banded electric knifefish, is a diverse genus with a range that extends from Argentina to southern Mexico and includes species distributed both east (cis-Andean) and west (trans-Andean) of the Andes. Each Gymnotus species exhibits a distinctive electric organ discharge (EOD), used for communication and navigation. Here, I present a new molecular phylogenetic hypothesis for 35 Gymnotus species based on two mitochondrial (cyt b and 16S) and two nuclear genes (RAG2 and Zic1). I found that the trans-Andean species are distributed in four distinct lineages with varying amounts of divergence from their closest cis-Andean sister taxa. I suggest that not all trans-Andean species evolved as a result of the orogeny of the Andes. I evaluate EOD phase number evolution in Gymnotus and find a trend for reduced phase numbers in both cis- and trans-Andean regions. Finally, I suggest hypotheses to account for the patterns of EOD phase number diversification.
URI: http://hdl.handle.net/1807/30525
Appears in Collections:Master

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