A molecular phylogenetic appraisal of the systematics of the Aglaopheniidae (Cnidaria: Hydrozoa, Leptothecata) from the north-east Atlantic and west Mediterranean

Authors

  • CARLOS J. MOURA,

    Corresponding author
    1. Departamento de Biologia, Centro de Estudos do Ambiente e do Mar (CESAM), Universidade de Aveiro, Campus Universitário de Santiago, 3810-193, Aveiro, Portugal
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  • MARINA R. CUNHA,

    1. Departamento de Biologia, Centro de Estudos do Ambiente e do Mar (CESAM), Universidade de Aveiro, Campus Universitário de Santiago, 3810-193, Aveiro, Portugal
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  • FILIPE M. PORTEIRO,

    1. Departamento de Oceanografia e Pescas, Universidade dos Açores, Cais de Santa Cruz, 9901-862, Horta, Açores, Portugal
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  • ALEX D. ROGERS

    1. Institute of Zoology, Zoological Society of London, Regent's Park, London NW1 4RY, UK
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    • Current address: Department of Zoology, University of Oxford, Tinbergen Building, South Parks Road, Oxford, OX1 3PS, UK.


E-mail: carlos.moura@mail.com

Abstract

The hydrozoan family Aglaopheniidae (Cnidaria) is widespread worldwide and contains some of the most easily recognizable hydroids because of their large colony size and characteristic microscopic structure. The systematics of the group has, however, been controversial and dedicated molecular analyses are lacking. We therefore analysed existing and new 16S rRNA sequences of Aglaopheniidae, in a total of 98 16S sequences corresponding to 25 putative species (25 nominal and three undescribed) from seven genera. The monophyly of the subfamilies Gymnangiinae and Aglaopheniinae, and tribes Aglaopheniini and Cladocarpini were not verified with 16S sequence data. The genera Gymnangium and Aglaophenia can only be considered valid if both Gymnangium gracicaule and Aglaophenia latecarinata are removed from their respective genera. The phenotypically similar Cladocarpus and Streptocaulus are probably monophyletic and clearly distinct genetically. The genus Lytocarpia may be polyphyletic. The nominal species Aglaophenia pluma, Aglaophenia tubiformis, and Aglaophenia octodonta are probably conspecific, as are also the species Aglaophenia acacia and Aglaophenia elongata. The 16S data revealed the existence of two potentially unnamed species of Aglaophenia respectively from the Azores and Madeira. The phylogeographical structure of the taxa with the greatest representation of haplotypes from the north-east Atlantic and Mediterranean, revealed the influence of Mediterranean waters in Madeira and the Azores, and gene flow between deep waters of the Mediterranean and Atlantic. The last glaciations in Europe may have caused genetic bottlenecks but also high intraspecific haplotype diversity. Finally, Macrorhynchia philippina was detected in samples from Madeira and possibly represents an invasive species.

© 2012 The Linnean Society of London, Zoological Journal of the Linnean Society, 2012, 164, 717–727.

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