ABSTRACT
The genus Artemia Leach 1819 is an exceptionally favorable system for the study of evolutionary processes. With regard to the study of evolutionary genetics, sexual populations may be compared with asexual forms. This chapter aims to anticipate some taxonomic problems with examples of partial barriers to gene flow. It examines the influence of heterozygosity on female reproductive success. The chapter discusses the presence of partial reproductive isolation within the A. franciscana superspecies subsequently under the headings "Ecological Isolation" and "Hybridization". The genus Artemia is a complex of sibling species and superspecies defined by the criterion of reproductive isolation. The chapter reviews the cross-fertility tests which were the basis of the diagnosis of sibling species in Artemia. Among the bisexual populations, the first demonstrations of reproductive isolation were between wild-type Mediterranean saltern shrimps and either "California shrimps" or A. persimilis. In an ideal experimental design, each of the known Artemia populations would be crossed in a matrix.
