On the status of the Hawaiian seahorses Hippocampus hilonis, H. histrix and H. fisheri (Syngnathidae)

Abstract

Three species of seahorses of the genus Hippocampus are recognized within the Hawaiian Islands, H. kuda, H. fisheri and H. histrix. Based on molecular and morphological evidence H. kuda is treated here as two subspecies, the Hawaiian H. kuda hilonis and H. kuda kuda from elsewhere in the Indo-Pacific region. Molecular analysis also indicates that recent populations of H. kuda hilonis are not based on introduced fishes as their cytb sequence is identical to that of the H. hilonis holotype. Hippocampus fisheri is endemic to the Hawaiian Islands. The Hawaiian record of H. histrix is based on a specimen collected from O‘ahu in 1877 and one reported from Maui in 1928. The specimens are identified correctly, and there is no reason to doubt these old records, illogical as they seem.

Keywords:

• Hawaiian Islands
• Hippocampus
• meristic and morphological comparison
• molecular study
• Syngnathidae

Published in collaboration with the University of Bergen and the Institute of Marine Research, Norway, and the Marine Biological Laboratory, University of Copenhagen, Denmark

Published in collaboration with the University of Bergen and the Institute of Marine Research, Norway, and the Marine Biological Laboratory, University of Copenhagen, Denmark

Acknowledgements

The authors thank Sara Lourie of McGill University for sharing her data on Hippocampus histrix; Healy Hamilton and Sara Lourie for discussion and feedback; Yvonne Chan for providing help with ancient DNA extraction; Trisha Atwood, Karen Brittain, Kaipo Perez, Sonia Rowley, Clyde Tamaru, Carol Cozzi-Schmarr (Ocean Rider Inc.), and the Modern Pet Center for assistance with sample collection; David Itano and Geoffrey Walker for the photograph of Hippocampus fisheri in Figure 3A; Arnold Suzumoto of the Bishop Museum, Honolulu, and Tan Heok Hui of the Raffles Museum of Biodiversity Research, Singapore, for assisting with museum specimens; Sandra Raredon, Jeffrey Williams, and Lynne Parenti of the National Museum of Natural History of the Smithsonian Institution for the loan of the holotype of H. hilonis and allowing subsampling; and Karsten Hartel and Andrew Williston of the Museum of Comparative Zoology of Harvard University for information on and the photograph of Hippocampus histrix. We also thank Helen A. Randall for Figure 5 and her review of the manuscript. Earlier versions of this manuscript were improved by helpful comments from Zac Forsman and Brian Bowen. Funding was provided by NSF OCE-0623678, OCE-0454873, DBI-0829272 and NMSP MOA#2005-008/66882 to RJT and Brian Bowen. This is HIMB #1420 and SOEST #8047.

Notes

Published in collaboration with the University of Bergen and the Institute of Marine Research, Norway, and the Marine Biological Laboratory, University of Copenhagen, Denmark