and evolutionary origins of parthenogenetic Artemia (Crustacea: Anostraca) with different ploidies. -Zoologica Scripta, 45, 421-436. Using two nuclear (ITS1 and Na + /K + ATPase) and three mitochondrial (COI, 16S and 12S) markers, we determined the genetic variation and evolutionary relationship of parthenogenetic and bisexual Artemia. Our analyses revealed that mitochondrial genes had higher genetic variation than nuclear genes and that the 16S showed more variety than the other mitochondrial genes in parthenogenetic populations. Triploid parthenogens showed lower genetic variation than diploid ones, whereas the tetra-and pentaploids had greater genetic distance than diploid parthenogens. No shared haplotype was found between individuals of parthenogenetic populations and Asian bisexual species with the exception of Na + /K + ATPase (Artemia tibetiana). Only mitochondrial markers can demonstrate phylogenetic relationships, and showed that the parthenogenetic Artemia is a polyphyletic group in which the diploid lineages share a common ancestor with Artemia urmiana while tetraploids are closely related to Artemia sinica. The triploid and pentaploid linages are likely to be directly derived from diploid and tetraploid parthenogens, respectively. Subsequently, west Asia is origin for di-/ triploids, and tetra-/pentaploids rose from East Asia.

Urmia Lake, with a surface area between 4000 to 6000 km2, is a hypersaline lake located in northwest Iran. It is the saltiest large lake in the world that supports life. Urmia Lake National Park is the home of an almost endemic crustacean species known as the brine shrimp, Artemia urmiana. Other forms of life include several species of algae, bacteria, microfungi, plants, birds, reptiles, amphibians and mammals. As a consequence of this unique biodiversity, this lake has been selected as one of the 59 biosphere reserves by UNESCO. This paper provides a comprehensive species checklist that needs to be updated by additional research in the future.

Native American Artemia franciscana has become an introduced species in the Old World due to the rapid development of the aquaculture industry in Eurasia. The recent colonisation of A. franciscana in Mediterranean regions and Asia has been well documented, but Australia is a continent where the dispersal of this species is not well understood. In the present study, we sequenced the cytochrome oxidase subunit I (COI) and examined the phylogenetic relationships, haplotype network and population genetic structure of Artemia from four geographical localities in Australia and two American native localities. Our results confirmed the colonisation of Australia in all four localities by A. franciscana. First, we document the occurrence of Artemia in Mulgundawa and St Kilda localities in Australia. The Dampier population is a monomorphic population, but there is high genetic variation and a degree of demographic expansion observed in other introduced A. franciscana populations in Australia. This observation suggests an interaction between environmental conditions and adaptive potentials of A. franciscana. Our findings imply that populations from St Kilda and Port Hedland might have originated from a San Francisco Bay source, while the two other locations resulted from admixture between Great Salt Lake and San Francisco Bay sources, perhaps resulting from secondary introduction events.

The genus Artemia Leach, 1819 is a cosmopolitan halophilic crustacean, consisting of bisexual species and obligate parthenogenetic populations. Asia is rich in Artemia biodiversity. More than 530 Artemia sites have been recorded from this area and more than 20 species/subspecies/variety names have been used for them. There exist various problems in the nomenclature, identification, and phylogenetic status of Artemia native to Asia, which are discussed in this paper.

Urmia Lake, the largest natural habitat of the brine shrimp Artemia urmiana, has progressively desiccated over the last two decades, resulting in a loss of 80% of its surface area and producing thousands of hectares of arid salty land. This ecological crisis has seriously affected the lake’s native biodiversity. Artemia urmiana has lost more than 90% of its population during the decade from 1994 (rainy period) to 2004 (drought period) due to salinity increasing to saturation levels (∼300 g/l). We studied the influence of this ecological crisis on the genetic diversity of A. urmiana in Urmia Lake, based on one cyst collections in 1994 and 2004. AMOVA analysis on ISSR data demonstrated a 21% genetic variation and there was a 5.5% reduction of polymorphic loci between samples. PCoA showed that 77.42% and 68.75% of specimens clustered separately in 1994 and 2004, respectively. Our analyses of four marker genes revealed different genetic diversity patterns with a decrease of diversity at ITS1 and an increase for Na+/K+ ATPase. There was no notable difference in genetic variation detected for COI and 16S genes between the two periods. However, they represented distinctly different haplotypes. ITS1 and COI followed a population expansion model, whereas Na+/K+ ATPase and 16S were under demographic equilibrium without selective pressure in the 1994 samples. Neutrality tests confirmed the excess of rare historical and recent mutations present in COI and ITS1 in both samples. It is evident that a short-term ecological disturbance has impacted the genetic diversity and structure of A. urmiana.