Grants and Contracts Details
Description
Hellbender salamanders (Cryptobranchus alleganiensis) are large, obligately aquatic
salamanders that were once widespread and abundant in streams and rivers across the eastern and
central United States. These long-lived salamanders are restricted to cold, highly oxygenated
aquatic habitats and serve as key predators in riverine ecosystems. Hellbender populations have
been rapidly declining throughout their historical distribution over the past forty years due to the
combined effects of habitat degradation and fragmentation, pollution of aquatic ecosystems,
emerging infectious diseases, and poaching. Many populations are completely extirpated and
those that remain are increasingly fragmented, elevating the risk of local and global extinction.
Cryptobranchus is listed by the IUCN as Near Threatened and populations in the Ozark
Mountains were recently listed as Federally Endangered by U.S. Fish and Wildlife Service.
Recent conservation efforts have sought to curb these precipitous declines by identifying and
protecting remaining populations, by bolstering declining populations with captive bred
individuals, and by reintroducing hellbenders into extirpated areas. Despite these efforts, several
impediments must still be surmounted in order to protect this ecologically important salamander
from impending extinction.
Although hellbenders are currently classified as a single species with two recognized
subspecies (C. a. alleganiensis in the Appalachians and C. a. bishopi in the Ozark highlands),
emerging genetic research suggests that this genus may comprise several cryptic species, each
substantially smaller and more imperiled than previously realized. The current lack of
understanding of species boundaries in this group prevents comprehensive conservation
management. Furthermore, effective conservation efforts with Cryptobranchus require detailed
knowledge of the demographic and population genetic parameters of distinct lineages, such as
rates and patterns of migration and gene flow, effective population sizes, levels of genetic
diversity, and the extent of adaptive differences between populations.
Here I propose an in-depth population genetic and phylogenetic analysis of hellbenders
from across the Ozark highlands of Missouri and Arkansas, including sampling from all river
systems where this species occurs in the western portion of its range. This project is aimed at
resolving the evolutionary relationships among these most imperiled hellbender populations by
leveraging emerging techniques for genome-wide DNA sequencing to delimit cryptic species
boundaries and to detect patterns of local adaptation. This work comprises fits within the broader
context of my thesis work at University of Kentucky which seeks to understand the ways in
which changes in the genomes of organisms drive and reflect the divergence between lineages.
At a basic level, this research seeks to shed light on the evolutionary forces which drive
divergence during the earliest stages of speciation. At a more applied level, insights from this
work will inform conservation management decisions in terms of captive breeding and
repatriation efforts.
Status | Finished |
---|---|
Effective start/end date | 2/12/14 → 9/30/15 |
Funding
- KY Academy of Science Foundation: $994.00
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