Journal of the Marine Biological Association of the UK

Research Article

Phylogenetics of Hydroidolina (Hydrozoa: Cnidaria)

Paulyn Cartwrighta1 c1, Nathaniel M. Evansa1, Casey W. Dunna2, Antonio C. Marquesa3, Maria Pia Migliettaa4, Peter Schucherta5 and Allen G. Collinsa6

a1 Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, KS 66049, USA

a2 Department of Ecology and Evolutionary Biology, Brown University, Providence RI 02912, USA

a3 Departamento de Zoologia, Instituto de Biociências, Universidade de São Paulo, São Paulo, SP, Brazil

a4 Department of Biology, Pennsylvania State University, University Park, PA 16802, USA

a5 Muséum d'Histoire Naturelle, CH-1211, Genève, Switzerland

a6 National Systematics Laboratory of NOAA Fisheries Service, NMNH, Smithsonian Institution, Washington, DC 20013, USA


Hydroidolina is a group of hydrozoans that includes Anthoathecata, Leptothecata and Siphonophorae. Previous phylogenetic analyses show strong support for Hydroidolina monophyly, but the relationships between and within its subgroups remain uncertain. In an effort to further clarify hydroidolinan relationships, we performed phylogenetic analyses on 97 hydroidolinan taxa, using DNA sequences from partial mitochondrial 16S rDNA, nearly complete nuclear 18S rDNA and nearly complete nuclear 28S rDNA. Our findings are consistent with previous analyses that support monophyly of Siphonophorae and Leptothecata and do not support monophyly of Anthoathecata nor its component subgroups, Filifera and Capitata. Instead, within Anthoathecata, we find support for four separate filiferan clades and two separate capitate clades (Aplanulata and Capitata sensu stricto). Our data however, lack any substantive support for discerning relationships between these eight distinct hydroidolinan clades.

(Received November 30 2007)

(Accepted May 12 2008)

(Online publication July 29 2008)


c1 Correspondence should be addressed to: Paulyn Cartwright, Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, KS 66049, USA email: