Title

Hybrids lost: fading introgression in two freshwater sculpin populations

Presentation Type

Poster

Abstract

Rates of hybridization and introgression are increasing worldwide because of human mediated actions, such as species introductions and habitat degradation, and are having deleterious effects on native populations. The conservation implications of hybridization and introgression varies among species, thus understanding patterns of hybridization is an important step as we explore species interactions and evaluate potential consequences of genetic exchange. Although it is known that species of Cottus (sculpin) can hybridize, few have examined the potential patterns of hybridization among sculpins to explore potential implications on populations in the watersheds in the Rocky Mountain region. Several C. cf. cognatus X C. sp. hybrid individuals were previously detected in Trout and Fish Creeks in the lower Clark Fork River, MT. We collected tissues samples across the length of Trout and Fish Creeks in 2012 to discern patterns in hybridization. Little evidence of introgression was present in 2012 samples. We then analyzed 46 more of the MFWP 2007 samples and compared similar numbers of samples from 2012 samples from overlapping locations in Trout Creek and in Fish Creek. There was substantial loss of in the number of hybrids and proportion of C. cognatus alleles in both populations from 2007 to 2012. This reduction could be indicative of reduced fitness of hybrids or the reduction in C. cognatus alleles observed could also be due to genetic swamping due to relatively high proportions of the C. sp. parental type.

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Apr 12th, 11:00 AM Apr 12th, 12:00 PM

Hybrids lost: fading introgression in two freshwater sculpin populations

UC Ballroom

Rates of hybridization and introgression are increasing worldwide because of human mediated actions, such as species introductions and habitat degradation, and are having deleterious effects on native populations. The conservation implications of hybridization and introgression varies among species, thus understanding patterns of hybridization is an important step as we explore species interactions and evaluate potential consequences of genetic exchange. Although it is known that species of Cottus (sculpin) can hybridize, few have examined the potential patterns of hybridization among sculpins to explore potential implications on populations in the watersheds in the Rocky Mountain region. Several C. cf. cognatus X C. sp. hybrid individuals were previously detected in Trout and Fish Creeks in the lower Clark Fork River, MT. We collected tissues samples across the length of Trout and Fish Creeks in 2012 to discern patterns in hybridization. Little evidence of introgression was present in 2012 samples. We then analyzed 46 more of the MFWP 2007 samples and compared similar numbers of samples from 2012 samples from overlapping locations in Trout Creek and in Fish Creek. There was substantial loss of in the number of hybrids and proportion of C. cognatus alleles in both populations from 2007 to 2012. This reduction could be indicative of reduced fitness of hybrids or the reduction in C. cognatus alleles observed could also be due to genetic swamping due to relatively high proportions of the C. sp. parental type.