Abstract
The presence of Triops cancriformis has not been broadly reported outside Europe or North Africa. Among the few exceptions, including the studies on the Middle Eastern populations, genetic information is almost completely absent. This study confirms the presence of T. cancriformis as a single population in Rawdat Nu'man, Qatar, using both morphological and genetic data. Their carina and telson were consistent with the traits in the subspecies of T. c. simplex, while the COI and 16S sequence analysis revealed that the population of Rawdat Nu'man is consistent with T. c. cancriformis. As this morphology vs. genetics inconsistency has been reported previously, the observation in the Qatari T. cancriformis further calls for reassessment of the status of the two subspecies. The COI-based phylogeny shows the Nu'man population being most closely related to a population in Königswartha, Germany. Further, the presence of only female individuals, the absence of genetic diversity, and limited local distribution indicate recent colonization in Qatar, possibly through passive dispersal via diapausing cysts carried by avian vectors during seasonal migrations.