Settling taxonomic and nomenclatural problems in brine shrimps, Artemia (Crustacea: Branchiopoda: Anostraca), by integrating mitogenomics, marker discordances and nomenclature rules

High morphological plasticity in populations of brine shrimp subjected to different environmental conditions, mainly salinity, hindered for centuries the identification of the taxonomic entities encompassed within . In addition, the mismatch between molecular and morphological evolution rates complicates the characterization of evolutionary lineages, generating taxonomic problems. Here, we propose a phylogenetic hypothesis for based on two new complete mitogenomes, and determine levels of congruence in the definition of evolutionary units using nuclear and mtDNA data. We used a fossil of to calibrate the molecular clock and discuss divergence times within the genus. The hypothesis proposed herein suggests a more recent time frame for lineage splitting than previously considered. Phylogeographic analyses were performed using GenBank available mitochondrial and nuclear markers. Evidence of gen e flow, identified through discordances between nuclear and mtDNA markers, was used to reconsider the specific status of some taxa. As a result, we consider to be represented by five evolutionary units: Southern Cone, Mediterranean-South African, New World, Western Asian, and Eastern Asian Lineages. After an exhaustive bibliographical revision, unavailable names for nomenclatural purposes were discarded. The remaining available names have been assigned to their respective evolutionary lineage. The proper names for the evolutionary units in which brine shrimps are structured remain as follows: Piccinelli & Prosdocimi, 1968 for the Southern Cone Lineage, (Linnaeus, 1758) for the Mediterranean-SouthAfrican Lineage, Günther, 1899 for the Western Asian Lineage, and Cai, 1989 for the Eastern Asian Lineage. The name Verrill, 1869 has nomenclatural priority over Kellogg, 1906 for naming the New World Lineage. New synonymies are proposed for ( Grochowski, 1896 , and Bowen & Sterling, 1978 ), (= Kellogg, 1906 ., and var. Sars, 1904 ); (= Fischer de Waldheim, 1834 , Fischer, 1851 , King, 1855 , , Entz, 1886 , Walter, 1887 , Bowen & Sterling, 1978 , Qian & Wang, 1992 , Naganawa, 2017 , and Naganawa & Mura, 2017 ). Internal deep nuclear structuring within the and clades, might suggest the existence of additional evolutionary units within these taxa.