I used microsatellite markers to assess reproductive isolation between cryptic, sympatric lineages of a freshwater catfish (Pimelodella chagresi ). These are "cryptic" lineages because they cannot be distinguished visually on the basis of morphological characters, and currently they are recognized as a single species. Previous analyses utilizing mitochondrial DNA (mtDNA) indicated that two highly divergent lineages are present in lower Central America, and that these lineages are the result of independent colonization events from South American source populations. I isolated eight dinucleotide repeats from P. chagresi and designed primers to amplify these microsatellite loci. I sampled fishes from four Panamanian watersheds. The congruence of microsatellite data with mtDNA indicated that these taxa are reproductively isolated and should be considered as separate species despite the lack of morphological differentiation. Both lineages exhibit a high degree of divergence among populations inhabiting isolated freshwater drainages, but the lineages differ in their intra-watershed population structure.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.82294 |
| Date | January 2005 |
| Creators | Moeser, Andrew A. |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (Department of Biology.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 002209279, proquestno: AAIMR12505, Theses scanned by UMI/ProQuest. |
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