GENETIC ADMIXTURE IN THE SAN DIEGO FAIRY SHRIMP (BRANCHINECTA SANDIEGONENSIS)

Ketan V Patel; San Diego State University; Kpatel102486@gmail.com; Andrew J. Bohonak PhD, Marie Simovich PhD, Chuck Black PhD, Natalie S. Goddard, Nicholas Graige

Because only 3-7% of historically present vernal pool habitat remains in coastal San Diego County, conservation efforts must prioritize both maintenance of these pools and the genetic integrity of their inhabitants. Simovich et al (2013) suggested admixture between the endemic San Diego fairy shrimp (Branchinecta sandiegonensis) and the versatile fairy shrimp (Branchinecta lindahli). They published a hybrid index based on female dorsolateral spinal patterns (which cannot be used for males and immature individuals). Using morphologically scored females from multiple source populations, we have developed a genomic hybrid index comprised of 23 single nucleotide polymorphisms that are alternatively fixed between the two Branchinecta species. This genomic hybrid index can be used to validate the existing morphological hybrid index, detect hybrid individuals, identify admixture in juveniles and males, and estimate natural admixture rates. Genetic assessment San Diego Fairy Shrimp populations and genetic monitoring over time will better inform management and conservation practices in the remaining coastal vernal pool ecosystems.

Molecular Ecology and Wildlife Conservation Genetics     Student Paper