Invasive species are detrimental to native species and when hybridization is involved a decrease in biodiversity may result. Cyprinodon variegatus is an invasive species that has caused devastation to several Cyprinodon species through rapid hybridization and genetic introgression. Cyprinodon rubrofluviatilis is native to the Brazos, Wichita and Red Rivers but fish collected between 2006-2012 from the Brazos River expressed intermediate morphological traits suggesting hybridization had occurred. My objective was to investigate if C. variegatus and C. rubrofluviatilis had hybridized in the Brazos River and if so, to determine the extent of introgression. Molecular analysis of specimens collected between 2013-2017 identified low levels of introgression in 2013-2015 but no signs of hybridization in 2017. Morphological analysis showed significant differences between species, genetic grouping, river, and most drainages with little evidence of intermediate phenotypes. Although hybridization and introgression between C. variegatus and C. rubrofluviatilis is not widespread, it remains a threat to native Cyprinodon in this region.
","abstract_html":"<p>Invasive species are detrimental to native species and when hybridization is involved a decrease in biodiversity may result. <em>Cyprinodon variegatus </em>is an invasive species that has caused devastation to several <em>Cyprinodon </em>species through rapid hybridization and genetic introgression. <em>Cyprinodon rubrofluviatilis </em>is native to the Brazos, Wichita and Red Rivers but<em> </em>fish collected between 2006-2012 from the Brazos River expressed intermediate morphological traits suggesting hybridization had occurred. My objective was to investigate if <em>C. variegatus</em> and <em>C. rubrofluviatilis</em> had hybridized in the Brazos River and if so, to determine the extent of introgression. Molecular analysis of specimens collected between 2013-2017 identified low levels of introgression in 2013-2015 but no signs of hybridization in 2017. Morphological analysis showed significant differences between species, genetic grouping, river, and most drainages with little evidence of intermediate phenotypes. Although hybridization and introgression between <em>C. variegatus</em> and<em> C. rubrofluviatilis </em>is not widespread, it remains a threat to native <em>Cyprinodon</em> in this region.</p>","abstract_has_math":false,"creators":["Ayers, Kristina"],"institution":null,"degree_name":"Master of Science - Biology","degree_level":"Thesis","degree_discipline":"Biology","degree_department":null,"school":null,"contributors":["Dr. Jennifer Gumm","Dr. Matthew Kwiatkowski","Dr. Vance Imhoff"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2018,"date_issued":"2018-08-01T07:00:00Z","date_published":"2018-08-01T07:00:00Z","updated_at":"2026-07-24T04:30:22Z","subjects":["population biology","conservation genetics","hybridization","geometric morphometrics","Cyprinodon rubrofluviatilis","Cyprinodon variegatus"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://scholarworks.sfasu.edu/etds/211","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Dr. Jennifer Gumm","Dr. Matthew Kwiatkowski","Dr. Vance Imhoff"]},{"key":"dc:creator","label":"Author","values":["Ayers, Kristina"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.available","label":"Dc Date Available","values":["2020-08-15T07:00:00Z"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Biology"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science - Biology"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["population biology","conservation genetics","hybridization","geometric morphometrics","Cyprinodon rubrofluviatilis","Cyprinodon variegatus"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://scholarworks.sfasu.edu/etds/211"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Invasive species are detrimental to native species and when hybridization is involved a decrease in biodiversity may result. Cyprinodon variegatus is an invasive species that has caused devastation to several Cyprinodon species through rapid hybridization and genetic introgression. Cyprinodon rubrofluviatilis is native to the Brazos, Wichita and Red Rivers but fish collected between 2006-2012 from the Brazos River expressed intermediate morphological traits suggesting hybridization had occurred. My objective was to investigate if C. variegatus and C. rubrofluviatilis had hybridized in the Brazos River and if so, to determine the extent of introgression. Molecular analysis of specimens collected between 2013-2017 identified low levels of introgression in 2013-2015 but no signs of hybridization in 2017. Morphological analysis showed significant differences between species, genetic grouping, river, and most drainages with little evidence of intermediate phenotypes. Although hybridization and introgression between C. variegatus and C. rubrofluviatilis is not widespread, it remains a threat to native Cyprinodon in this region.
"]},{"key":"dc:title","label":"Title","values":["Analysis of Hybridization Between Native and Invasive Pupfishes (Cyprinodon)"]}]}],"canonical_facts":{"dc:contributor":["Dr. Jennifer Gumm","Dr. Matthew Kwiatkowski","Dr. Vance Imhoff"],"dc:creator":["Ayers, Kristina"],"dc:date.available":["2020-08-15T07:00:00Z"],"dc:description.abstract":["Invasive species are detrimental to native species and when hybridization is involved a decrease in biodiversity may result. Cyprinodon variegatus is an invasive species that has caused devastation to several Cyprinodon species through rapid hybridization and genetic introgression. Cyprinodon rubrofluviatilis is native to the Brazos, Wichita and Red Rivers but fish collected between 2006-2012 from the Brazos River expressed intermediate morphological traits suggesting hybridization had occurred. My objective was to investigate if C. variegatus and C. rubrofluviatilis had hybridized in the Brazos River and if so, to determine the extent of introgression. Molecular analysis of specimens collected between 2013-2017 identified low levels of introgression in 2013-2015 but no signs of hybridization in 2017. Morphological analysis showed significant differences between species, genetic grouping, river, and most drainages with little evidence of intermediate phenotypes. Although hybridization and introgression between C. variegatus and C. rubrofluviatilis is not widespread, it remains a threat to native Cyprinodon in this region.
"],"dc:identifier":["https://scholarworks.sfasu.edu/etds/211"],"dc:subject":["population biology","conservation genetics","hybridization","geometric morphometrics","Cyprinodon rubrofluviatilis","Cyprinodon variegatus"],"dc:title":["Analysis of Hybridization Between Native and Invasive Pupfishes (Cyprinodon)"],"thesis:degree_discipline":["Biology"],"thesis:degree_level":["Thesis"],"thesis:degree_name":["Master of Science - Biology"]},"updated_at":"2026-07-24T04:30:22Z"}