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

            MICHAEL KORN, FEDERICO MARRONE, JOSE L. PÉREZ-BOTE, MARGARIDA MACHADO, MARGARIDA CRISTO,
            LUÍS CANCELA DA FONSECA & ANNA K. HUNDSDOERFER





            Accepted: 9 March 2006          Korn, M., Marrone, F., Pérez-Bote, J. L., Machado, M., Cristo, M., Cancela da Fonseca, L.
            doi: 10.1111/j.1463-6409.2006.00230.x  & Hundsdoerfer, A. K. (2006). Sister species within the Triops cancriformis lineage (Crustacea,
                                            Notostraca). — Zoologica Scripta, 35, 301–322.
                                            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, Portu-
                                            gal. 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


            Introduction                                     Both occur almost exclusively in temporary pools where they
            The Notostraca are an ancient group of branchiopod  can endure prolonged dry phases via resting eggs (encysted
            crustaceans, their fossil record dating back to the upper  embryos in diapause). A well-known peculiarity of the
            Carboniferous (Dumont & Negrea 2002). They consist of  Notostraca is their high variability in most — or even all —
            two genera with worldwide distributions, Triops and Lepidurus.  morphological key characters, even within populations. For


            © 2006 The Authors. Journal compilation © 2006 The Norwegian Academy of Science and Letters • Zoologica Scripta, 35, 4, July 2006, pp301–322  301
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