Zoological Studies 59:14 (2020) doi:10.6620/ZS.2020.59-14 Open Access Molecular Evaluation of the Fairy Shrimp Family Branchinectidae (Crustacea: Anostraca) Supports Peripatric Speciation and Complex Divergence Patterns D. Christopher Rogers1,* and Andres Aguilar2 1Kansas Biological Survey, Kansas University, Higuchi Hall, 2101 Constant Avenue, Lawrence, KS 66047-3759 USA. *Correspondence: E-mail:
[email protected] (Rogers) 2Department of Biological Sciences, California State University, 5151 State University Drive Los Angeles, CA 90032 USA. E-mail:
[email protected] (Aguilar) Received 13 August 2019 / Accepted 21 February 2020 / Published 28 April 2020 Communicated by Benny K.K. Chan The Branchinectidae is a diverse and widely distributed group of anostracans. The majority of work on the group has focused on the morphological delineation of taxa and biogeography. Here we present a molecular phylogeny for select members of the family to better understand the distribution of morphological variation among species, and test biogeographic models of speciation for the group. Although we conducted both molecular and morphological phylogenies for the Branchinectidae, the morphological analysis did not support our molecular phylogeny and it did not support previous species group concepts based on geography. Our molecular phylogenetic analysis suggests that the family may have originated in Eurasia and found support for numerous species groups. These phylogenetic groups assisted in delineating species groups that are all definable morphologically and/or ecologically. The peripatric speciation model was supported from our analysis, offering credence to previously published speciation models in anostracans. This suggests that these processes may be important in other Branchiopoda and should be rigorously evaluated when delineating species.