Meeting Abstract
Invasive species threaten biodiversity and native species through hybridization. This is the case with pupfish species throughout Texas and the Southwest. We are investigating the extent of hybridization and genetic introgression between the invasive sheepshead minnow (Cyprinodon variegatus) and the Red River Pupfish (Cyprinodon rubrofluviatilis). Morphological characters have documented the presence of C. variegatus in the Brazos River and to identify possible hybrids. Based on patterns of morphological data collected between 2006 and 2012. the invasion of Sheepshead Minnow is advancing upstream at a rapid rate. This presents a serious threat to the remaining populations of C. rubrofluviatilis. We are using genetic analysis of microsatellites to confirm the presence of Sheepshead Minnow in the Brazos and Red Rivers. Preliminary genetic evidence suggests hybridization has occurred between these species. Analysis of samples collected from several locations between 2010 and 2015 allow us to track the progression of C. variegatus upstream and to determine the leading edge of the invasion. Resampling of specific locations also allows us to monitor the rate of introgression over the last five years. Understanding the extent to which hybridization and genetic introgression has occurred will help determine if conservation efforts are needed for C. rubrofluviatilis . Furthermore, genetic analysis will facilitate prompt conservation measures protecting C. rubrofluviatilis.
