Abstract
We present the reference genome of the Vernal Pool Fairy Shrimp Branchinecta lynchi. This branchiopod crustacean is endemic to California's freshwater ephemeral ponds. It faces enormous habitat loss and fragmentation as urbanization and agriculture have fundamentally changed the vernal pool landscape over the past 3 centuries. The assembled genome consists of 22 chromosome-length scaffolds that account for 96.85% of the total sequence. One hundred and ninety-five unscaffolded contigs comprise the rest of the genome's 575.6 Mb length. The genome is substantially complete with a BUSCO score of 90.0%. There is no immediately identifiable sex chromosome, typical for this class of organism. This new resource will permit researchers to better understand the adaptive capacity of this imperiled species, as well as answer lingering questions about anostracan physiology, sex determination, and development.