Sister species within the Triops cancriformis lineage ( Crustacea , Notostraca )

1 Korn, M. , Marrone, F. , Pérez-Bote, J. L. , Machado, M. , Cristo, M. , Cancela da Fonseca, L. & Hundsdoerfer, A. K. (2006). Sister species within the Triops cancriformis lineage (Crustacea, Notostraca). — Zoologica Scripta , ** , ***–***. We investigated the phylogenetic relationships among the three presently recognized subspecies of the tadpole shrimp, Triops cancriformis , using mitochondrial 16S and 12S rDNA sequences. Our results indicate that the taxon is divided into two distinct lineages. One lineage is formed of T. c. cancriformis populations and samples from northern Spain that had been classified as T. c. simplex in the most recent literature. The second lineage comprises all populations of T. c. mauritanicus and northern African populations of T. c. simplex . These two main lineages separated 2.3 to 8.9 million years ago, based on the range of inferred molecular clocks recognized for crustacean mtDNA sequence divergence. Percentages of divergence are in the range reported for recognized species in other notostracan lineages and we therefore propose to recognize them as two species, Triops cancriformis and Triops mauritanicus . The latter would comprise two subspecies in northern Africa, one consisting of the Moroccan populations of the former T. c. mauritanicus , the other comprising the African populations of the former T. c. simplex . It also includes three as-yet unnamed lineages. A comparison of morphological characters with the molecular data revealed that the former T. c. simplex cannot be reliably separated from T. c. cancriformis , using morphological characters that have hitherto been used to distinguish among subspecies of T. cancriformis . Our investigation is the first to demonstrate the presence of T. c. cancriformis in Africa (Tunisia). The genetic haplotypes of these populations are identical with haplotypes also occurring in Central and Western Europe, as well as in Sicily. Therefore, we hypothesize that the African populations of T. c. cancriformis represent a result of repeated long-distance dispersal across the Mediterranean Sea. Michael Korn, Limnological Institute, University of Konstanz, Mainaustr. 252, D-78464 Konstanz, Germany. E-mail: Michael.Korn@uni-konstanz.de Federico Marrone, Dipartimento di Scienze Botaniche, Università degli Studi di Palermo, Via Archirafi 38, 90123 Palermo, Italy. E-mail: federico.marrone@neomedia.it Jose L. Pérez-Bote, Área de Zoología, Facultad de Ciencias, Universidad de Extremadura, Avda. De Elvas s/n, E-06071 Badajoz, Spain. E-mail: jlperez@unex.es Margarida Machado, FCMA, Universidade do Algarve, Campus de Gambelas, 8005-139 Faro, Portugal. E-mail: mmalo@ualg.pt Margarida Cristo, FCMA, Universidade do Algarve, Campus de Gambelas, 8005-139 Faro, Portugal. E-mail: mcristo@ualg.pt Luís Cancela da Fonseca, FCMA, Universidade do Algarve, Campus de Gambelas, 8005-139 Faro, Portugal. E-mail: lfonseca@ualg.pt Anna K. Hundsdoerfer, DNA-Laboratory, Zoological Museum, State Natural History Collections Dresden, Königsbrücker Landstr. 159, D-01109 Dresden, Germany. E-mail: anna.hundsdoerfer @snsd.smwk. sachsen.de Blackwell Publishing Ltd Sister species within the Triops cancriformis lineage (Crustacea, Notostraca)