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Australian Journal of Zoology Australian Journal of Zoology Society
Evolutionary, molecular and comparative zoology
RESEARCH ARTICLE

Hippocampus queenslandicus Horne, 2001 – a new seahorse species or yet another synonym?

Peter R. Teske A D , Sara A. Lourie B , Conrad A. Matthee C and David M. Green B
+ Author Affiliations
- Author Affiliations

A Molecular Ecology and Systematics Group, Botany Department, Rhodes University, Grahamstown 6140, South Africa.

B Redpath Museum, McGill University, 859 Sherbrooke St West, Montréal, Québec, H3A 2K6, Canada.

C Evolutionary Genomics Group, Zoology Department, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa.

D Corresponding author. Email: P.Teske@ru.ac.za

Australian Journal of Zoology 55(3) 139-145 https://doi.org/10.1071/ZO07021
Submitted: 15 April 2006  Accepted: 2 May 2007   Published: 28 June 2007

Abstract

During the past six years, 15 new seahorse species (Syngnathidae: Hippocampus) have been described on the basis of morphological characters. This approach is known to be problematic, and most species names in Hippocampus are now considered to be synonyms. Genetic methods have great potential to resolve the confused taxonomy of the genus, but none have yet been incorporated into species descriptions. In the present study, mitochondrial control region and cytochrome b DNA sequences, as well as morphological data from the recently described Queensland seahorse, Hippocampus queenslandicus Horne, 2001, were compared with corresponding data from closely related seahorse species to determine whether there is strong support for distinction of this taxon. The haplotypes of H. queenslandicus were nested among haplotypes belonging to two of the three major Southeast Asian lineages of H. spinosissimus Weber, 1913. Although incomplete lineage sorting characteristic of very recently diverged species cannot be ruled out, the genetic results suggest that H. queenslandicus is paraphyletic. Morphometric analysis further fails to provide strong support for the species status of H. queenslandicus. We conclude that support for the distinctness of H. queenslandicus is weak, and indicate that it is a synonym of H. spinosissimus. The taxonomic validity of other recently described seahorse species should be similarly scrutinised using combined genetic and detailed morphological methods.


Acknowledgements

We are grateful to Paul Southgate, Martin Hicks, Sam McCulloch and Jeff Johnson for providing specimens of H. queenslandicus. Additional seahorse samples used in this study were contributed by Choo Chee Kuang, Sesh Serebiah, Monruedee Chaiyapu and the Project Seahorse collection at the Redpath Museum. Thanks also to Stan Weitzman for advice on statistical methods, and to two anonymous reviewers for their comments on earlier versions of the manuscript. This study was supported by an ex gratia bursary from the Harry Crossley Foundation and a Claude Harris Leon Foundation postdoctoral research fellowship awarded to PT, a McGill Major Scholarship awarded to SL, an NSERC Discovery grant to DG, Project Seahorse, the National Research Foundation, the University of Stellenbosch and Rhodes University.


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