FCE LTER Journal Articles


The number and diversity of source populations may influence the genetic diversity of newly introduced populations and affect the likelihood of their establishment and spread. We used the cytochrome b mitochondrial gene and nuclear microsatellite loci to identify the sources of a successful invader in southern Florida, USA, Cichlasoma urophthalmus (Mayan cichlid). Our cytochrome b data supported an introduction from Guatemala, while our microsatellite data suggested movement of Mayan Cichlids from the upper Yucatán Peninsula to Guatemala and introductions from Guatemala and Belize to Florida. The mismatch between mitochondrial and nuclear genomes suggests admixture of a female lineage from Guatemala, where all individuals were fixed for the mitochondrial haplotype found in the introduced population, and a more diverse but also relatively small number of individuals from Belize. The Florida cytochrome b haplotype appears to be absent from Belize (0 out of 136 fish screened from Belize had this haplotype). Genetic structure within the Florida population was minimal, indicating a panmictic population, while Mexican and Central American samples displayed more genetic subdivision. Individuals from the Upper Yucatán Peninsula and the Petén region of Guatemala were more genetically similar to each other than to fish from nearby sites and movement of Mayan Cichlids between these regions occurred thousands of generations ago, suggestive of pre-Columbian human transportation of Mayan Cichlids through this region. Mayan Cichlids present a rare example of cytonuclear disequilibrium and reduced genetic diversity in the introduced population that persists more than 30 years (at least 7–8 generations) after introduction. We suggest that hybridization occurred in ornamental fish farms in Florida and may contribute their establishment in the novel habitat. Hybridization prior to release may contribute to other successful invasions.


© 2014 Harrison et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.


Funding for travel was provided by a Tinker Fellowship from the Latin American and Caribbean Center at FIU. This material is based upon work supported by the National Science Foundation through the Florida Coastal Everglades Long-Term Ecological Research program under Cooperative Agreement DEB-9910514. Additional funding was provided by Sigma Xi and the DNA core facility at FIU. This is contribution # 279 from the Tropical Biology Program at Florida International University. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.