Abstract
Nomenclatural clarity is vital for the collection, dissemination, and retrieval of natural history information, which itself is necessary for effective conservation and management of species. Seahorses (genus Hippocampus) are small marine fishes that in many cases are heavily exploited and suffering severe population declines worldwide, leading to conservation concern and action. Here we provide a brief history of seahorse taxonomy, and attempt to clarify seahorse nomenclature by reducing redundancy and exposing areas of disagreement in need of further study. We provide an annotated list of the 41 species we currently recognize as valid, and describe their geographical distributions to offer a solid foundation for future research and conservation efforts. We base our conclusions on available morphological, genetic and distributional data, re-examination of the relevant literature, previous examination of almost all original type specimens, familiarity with many thousands of other live and dead specimens, and photographs of seahorses. This work should lead to greater taxonomic clarity by highlighting known research gaps and by ensuring that each species designation is justified by robust and defensible taxonomic protocols. Such clarity should facilitate greater efficacy in management and conservation.
References
Agapow, P.-M., Bininda-Emonds, O.R.P., Crandall, K.A., Gittleman, J.L., Mace, G.M., Marshall, J.C. & Purvis, A. (2004) The impact of species concept on biodiversity studies. The Quarterly Review of Biology 79, 161–179.
http://dx.doi.org/10.1086/383542Allen, G.R. & Erdmann, M.V. (2012) Reef Fishes of the East Indies. University of Hawaii Press, Honolulu, Hawaii, USA.
Anderson, P.A. (2012) Sexual dimorphism in morphometry and allometry of the adult lined seahorse, Hippocampus erectus. Copeia, 2012, 389–393.
http://dx.doi.org/10.1643/CG-11-003Armstrong, P. (2001) Genetic and morphological variation in pot-bellied seahorses (Hippocampus abdominalis): is there evidence for two species? B.Sc. (Hons.) Thesis, School of Aquaculture, University of Tasmania.
Avise, J. (1992) Molecular population structure and the biogeographic history of a regional fauna: a case history with lessons for conservation biology. Oikos, 63, 62–76.
http://dx.doi.org/10.2307/3545516Aylesworth, L. (2014) Hippocampus kuda. The IUCN Red List of Threatened Species, 2014, e.T10075A16664386.
Aylesworth, L., Lawson, J.M., Laksanawimol, P., Ferber, P. & Loh, T.-L. (2016) New records of the Japanese seahorse Hippocampus mohnikei in Southeast Asia lead to updates in range, habitat and threats. Journal of Fish Biology, 88 (4), 1620–1630.
http://dx.doi.org/10.1111/jfb.12908Bianconi, G.G. (1854) Specimina zoologica mosambicana, Fasciculus VIII: Pisces novi Mozambicani. Rendiconto delle Sessioni dell'Accademia delle Scienze dell'Instituto dei Bologna, 1853–1854, 68–69.
Bickford, D., Lohman, D.J., Sodhi, N.S., Ng, P.K.L., Meier, R., Winker, K., Ingram, K.K. & Das, I. (2007) Cryptic species as a window on diversity and conservation. Trends in Ecology & Evolution, 22, 148–155.
http://dx.doi.org/10.1016/j.tree.2006.11.004Bleeker, P. (1852) Bijdrage tot de kennis der ichthyologische fauna van Japan. Verhandelingen der Koninklijke Akademie van Wetenschappen, 1, 1–16.
Bleeker, P. (1855) Over eenige visschen van Van Diemensland. Verhandelingen der Koninklijke Akademie van Wetenschappen, 2, 1–30.
Bleeker, P. (1983) Atlas Icthyologique des Indes Orientales Neerlandaises. Plates for Volumes 11–14. Smithsonian Institution, Washington D.C.
Boehm, J.T., Waldman, J., Robinson, J.D. & Hickerson, M.J. (2015) Population genomics reveals seahorses (Hippocampus erectus) of the western mid-Atlantic coast to be residents rather than vagrants. PLOS ONE, 10, e0116219.
http://dx.doi.org/10.1371/journal.pone.0116219Boehm, J.T., Woodall, L., Teske, P.R., Lourie, S.A., Baldwin, C., Waldman, J. & Hickerson, M. (2013) Marine dispersal and barriers drive Atlantic seahorse diversification. Journal of Biogeography, 40, 1839–1849.
Boeseman, M. (1947) Revision of the fishes collected by Burger and Von Siebold in Japan. Zoologische Mededelingen, 28, i–vii + 1–242, plates 1–5.
BOLD (2016) Barcode of Life Data System. Hippocampus specimens on BOLD (Barcode of Life Data System) – February 2016.
http://dx.doi.org/10.5883/DS-SH2016Boulenger, G.A. (1900) Descriptions of new fishes from the Cape of Good Hope. Marine Investigations in South Africa, 8, 10–12.
Bowen, B.W., Bass, A.L., Rocha, L.A., Grant, W.S. & Robertson, D.R. (2001) Phylogeography of the trumpetfishes (Aulostomus): Ring species complex on a global scale. Evolution, 55, 1029–1039.
http://dx.doi.org/10.1111/j.0014-3820.2001.tb00619.xBradbury, I.R., Hubert, S., Higgins, B., Bowman, S., Borza, T., Paterson, I.G., Snelgrove, P.V.R., Morris, C.J., Gregory, R.S., Hardie, D., Hutchings, J.A., Ruzzante, D.E., Taggart, C.T. & Bentzen, P. (2013) Genomic islands of divergence and their consequences for the resolution of spatial structure in an exploited marine fish. Evolutionary Applications, 6, 450–461.
http://dx.doi.org/10.1111/eva.12026Cantor, T. (1849) Catalog of Malayan fishes. Journal of the Asiatic Society of Bengal, 18, i–xii + 983–1443+ Plates I–XIV.
Carvalho, M.R. de & Craig, M.T. (2011) Morphological and molecular approaches to the phylogeny of fishes: Integration or conflict? Zootaxa, 2946, 1–142.
Casey, S.P., Hall, H.J., Stanley, H.F. & Vincent, A.C.J. (2004) The origin and evolution of seahorses (genus Hippocampus): a phylogenetic study using the cytochrome b gene of mitochondrial DNA. Molecular Phylogenetics and Evolution, 30, 261–272.
http://dx.doi.org/10.1016/j.ympev.2003.08.018Castelnau, F.L. (1872) Contribution to the ichthyology of Australia. No. 1.--The Melbourne fish market (pp. 29–242). No. II.--Note on some South Australian fishes (pp. 243–247). Proceedings of the Zoological and Acclimatisation Society of Victoria, Melbourne, 1, 29–247.
Castelnau, F.L. (1873) Contribution to the ichthyology of Australia. Proceedings of the Zoological and Acclimatisation Society of Victoria, Melbourne, 2, 37–158.
Chang, C.-H., Lin, H.-Y., Jang-Liaw, N.-H., Shao, K.-T., Lin, Y.-S. & Ho, H.-C. (2013) The complete mitochondrial genome of the tiger tail seahorse, Hippocampus comes (Teleostei, Syngnathidae). Mitochondrial DNA, 24, 199–201.
http://dx.doi.org/10.3109/19401736.2012.744983Chen, J., Li, Q., Kong, L. & Yu, H. (2011) How DNA barcodes complement taxonomy and explore species diversity: the case study of a poorly understood marine fauna. PLOS ONE, 6, e21326.
http://dx.doi.org/10.1371/journal.pone.0021326Chen, L., Wang, X. & Huang, B. (2015) The genus Hippocampus - a review on traditional medicinal uses, chemical constituents and pharmacological properties. Journal of Ethnopharmacology, 162, 104–111.
http://dx.doi.org/10.1016/j.jep.2014.12.032Cisneros-Montemayor, A.M., West, K., Boiro, I.S. & Vincent, A.C.J. (2015) An assessment of West African seahorses in fisheries catch and trade. Journal of Fish Biology, 88, 751–759.
http://dx.doi.org/10.1111/jfb.12818Clark, L.F. (2015) The current status of DNA barcoding technology for species identification in fish value chains. Food Policy, 54, 85–94.
http://dx.doi.org/10.1016/j.foodpol.2015.05.005Curtis, J.M.R. (2006) A case of mistaken identity: skin filaments are unreliable for identifying Hippocampus guttulatus and Hippocampus hippocampus. Journal of Fish Biology, 69, 1855–1859.
http://dx.doi.org/10.1111/j.1095-8649.2006.01228.xCurtis, J. & Vincent, A.C.J. (2006) Life history of an unusual marine fish: Survival, growth and movement patterns of Hippocampus guttulatus Cuvier 1829. Journal of Fish Biology, 68, 707–733.
http://dx.doi.org/10.1111/j.0022-1112.2006.00952.xCuvier, G. (1817) Le Règne animal distribué d’après son organisation, pour servir de base à l'histoire naturelle des animaux et d'introduction à l'anatomie comparée. 1st ed. Paris.
Cuvier, G. (1829) Le Règne Animal, distribué d’après son organisation, pour servir de base à l'histoire naturelle des animaux et d'introduction à l'anatomie comparée. 2nd ed. Paris.
http://dx.doi.org/10.5962/bhl.title.49223Czembor, C.A. & Bell, E.M. (2012) Hippocampus capensis. The IUCN Red List of Threatened Species, e.T10056A495994.
http://dx.doi.org/10.2305/IUCN.UK.012-1.RLTS.T10056A495994.enDawson, C.E. (1979) Review of the polytypic doryrhamphine pipefish Oostethus brachyurus (Bleeker). Bulletin of Marine Science 29, 465–480.
Dawson, C.E. (1986) Syngnathidae. In: Whitehead, P. J. P., Bauchot, M.-L., Hureau, J.-C., Nielsen, J., and Tortonese, E. (Eds), Fishes of the North-eastern Atlantic and the Mediterranean. UNESCO, Paris, France, pp. 628–639.
Dobzhansky, T. (1935) A critique of the species concept in biology. Philosphy of Science, 2, 344–355.
http://dx.doi.org/10.1086/286379Dumeril, A. (1870) Tableau élémentaire de l'histoire naturelle des animaux. Tome Second. Ganoïdes, Dipnés, Lophobranches In Histoire naturelle des poissons ou ichthyologie generale, Paris, 500–526.
Eastman, C.R. (1915) Olden time knowledge of Hippocampus. Annual Report of the Smithsonian Institution, 349–357.
Encyclopedia of Life (2016) Encyclopedia of Life. Available from: www.eol.org (Accessed 12 Apr. 2016).
Eschmeyer, W., Fricke, R., Fong, J. & Polack, D. (2010) Marine fish diversity: history of knowledge and discovery (Pisces). Zootaxa, 2525, 19–50.
Eschmeyer, W.N. & Fricke, R.A. (2016) Catalog of Fishes: Genera, Species, References. Available from: www.calacademy.org/scientists/projects/catalog-of-fishes (Accessed 27 Jul. 2016)
Fedrizzi, N., Stiassny, M.L.J., Boehm, J.T., Dougherty, E.R., Amato, G. & Mendez, M. (2015) Population genetic structure of the dwarf seahorse (Hippocampus zosterae) in Florida. PloS one 10, e0132308.
http://dx.doi.org/10.1371/journal.pone.0132308Felício, A.K.C., Rosa, I.L., Souto, A. & Freitas, R.H.A. (2006) Feeding behavior of the longsnout seahorse Hippocampus reidi Ginsburg, 1933. Journal of Ethology, 24, 219–225.
http://dx.doi.org/10.1007/s10164-005-0189-8Foster, R. & Gomon, M. (2010) A new seahorse (Teleostei: Syngnathidae: Hippocampus) from south-western Australia. Zootaxa, 2613, 61–68.
Foster, S.J. & Vincent, A.C.J. (2004) Life history and ecology of seahorses: implications for conservation and management. Journal of Fish Biology, 65, 1–61.
http://dx.doi.org/10.1111/j.0022-1112.2004.00429.xFoster, S.J. & Vincent, A.C.J. (2016) Making Non-Detriment Findings for seahorses—a framework, Version 4. Project Seahorse, The University of British Columbia, Vancouver, Canada. 72 pp.
Francis, M. (1988) Coastal fishes of New Zealand, a diver’s identification guide. Auckland, New Zealand: Heinemann Reed, Division of Octopus Publishing Group (NZ) Ltd. 63 pp.
Fraser, D.J. & Bernatchez, L. (2001) Adaptive evolutionary conservation: towards a unified concept for defining conservation units. Molecular Ecology, 10, 2741–2752.
http://dx.doi.org/10.1046/j.1365-294X.2001.t01-1-01411.xFricke, R. (2004) Review of the pipefishes and seahorses (Teleostei: Syngnathidae) of New Caledonia, with descriptions of five new species. Stuttgarter Beitrage zur Naturkunde A, 668, 66 pp.
Fritzsche, R. (1980) Revision of the eastern Pacific Syngnathidae (Pisces, Syngnathiformes), including both recent and fossil forms. Proceedings of the California Academy of Sciences. 42, 181–227.
Fritzsche, R., Matsuura, K., Collette, B., Nelson, J., Dooley, J., Carpenter, K., Bartnik, S., Robinson, E., Sorensen, M. & Morgan, S.K. (2010) Hippocampus hendriki. The IUCN Red List of Threatened Species, 2010, e.T155100A4706397.
Froese, R. & Pauly, D. (2016) FishBase. Version 10/2015. Available from: http://www.fishbase.org (Accessed 27 Jul. 2016)
Garcia, L.M.B., Hilomen-Garcia, G. V., Celino, F.T., Gonzales, T.T. & Maliao, R.J. (2012) Diet composition and feeding periodicity of the seahorse Hippocampus barbouri reared in illuminated sea cages. Aquaculture, 358–359, 1–5.
http://dx.doi.org/10.1016/j.aquaculture.2012.06.013Ginsburg, I. (1933) Descriptions of five new species of seahorses. Journal of the Washington Academy of Sciences, 23, 560–563.
Ginsburg, I. (1937) Review of the seahorses (Hippocampus) found on the coasts of the American continents and of Europe. Proceedings of the United States National Museum, 83, 497–594.
http://dx.doi.org/10.5479/si.00963801.83-2997.497Girard, C.F. (1858) Fishes. In Reports of explorations and surveys, to ascertain the most practicable and economical route for a railroad from the Mississippi River to the Pacific Ocean. Beverly Tucker, Washington, DC.
Golani, D. & Fine, M. (2002) On the occurrence of Hippocampus fuscus in the eastern Mediterranean. Journal of Fish Biology, 60, 764–766.
http://dx.doi.org/10.1111/j.1095-8649.2002.tb01700.xGomon, M. & Kuiter, R. (2009) Two new pygmy seahorses (Teleostei: Syngnathidae: Hippocampus) from the Indo-West Pacific. aqua, International Journal of Ichthyology, 15, 37–44.
Gomon, M.F. (1997) A remarkable new pygmy seahorse (Syngnathidae: Hippocampus) from southeastern Australia, with a redescription of H. bargibanti Whitley from New Caledonia. Memoirs of the Museum of Victoria, 56, 245–253.
González, R., Dinghi, P., Corio, C., Medina, A., Maggioni, M., Storero, L. & Gosztonyi, A. (2014) Genetic evidence and new morphometric data as essential tools to identify the Patagonian seahorse Hippocampus patagonicus (Pisces, Syngnathidae). Journal of Fish Biology, 84, 459–474.
http://dx.doi.org/10.1111/jfb.12299Grady, J.M. & Quattro, J.M. (1999) Using character concordance to define taxonomic and conservation units. Conservation Biology, 13, 1004–1007.
http://dx.doi.org/10.1046/j.1523-1739.1999.98572.xGuichenot, A. (1850) Histoire Naturelle des reptiles et des poissons In Exploration scientifique de l’Algérie pendant les années 1840, 1841, 1842. Sciences Physiques Zoologie Imprimerie Nationale, 5, 120.
Günther, A. (1870) Catalogue of the fishes of the British Museum. Volume 8. Taylor and Francis, London, 549 pp.
Hamilton, H., Saarman, N.P., Moore, B., Short, G., Simison, W.B. & Gomon, M.F. (2010) A multigene phylogeny of syngnathid fishes. California Academy of Sciences and Museum Victoria, 27 pp. Available from: http://www.slideshare.net/humuhumufish/our-seahorse-research (Accessed 27 Jul. 2016)
Harasti, D. (2014) The biology, ecology and conservation of White’s seahorse Hippocampus whitei. PhD thesis, University of Technology, Sydney, Australia
Horne, M. (2001) A new seahorse species (Syngnathidae: Hippocampus) from the Great Barrier Reef. Records of the Australian Museum, 53, 243–246.
http://dx.doi.org/10.3853/j.0067-1975.53.2001.1330Isaac, N.J.B., Mallet, J. & Mace, G.M. (2004) Taxonomic inflation: its influence on macroecology and conservation. Trends in Ecology & Evolution, 19, 464–469.
http://dx.doi.org/10.1016/j.tree.2004.06.004iSeahorse (2016) iSeahorse. Available from: http://www.iSeahorse.org (Accessed 13 April 2016)
IUCN (2015) IUCN Red List of Threatened Species. Version 2015.4. Available from: http://www.iucnredlist.org (Accessed 12 Apr. 2016)
Jawad, L., Al-Kharusi, L. & Al-Mamry, J. (2011) On the occurrence of the Egyptian seahorse Hippocampus suezensis Duncker, 1940 in Muscat, Sultanate of Oman. Acta Adriatica, 52, 137–139.
Jones, A.G. & Avise, J.C. (2001) Mating systems and sexual selection in male-pregnant pipefishes and seahorses: Insights from microsatellite-based studies of maternity. Journal of Heredity, 92, 150–158.
http://dx.doi.org/10.1093/jhered/92.2.150Jones, A.G., Moore, G.I., Kvarnemo, C., Walker, D. & Avise, J.C. (2003) Sympatric speciation as a consequence of male pregnancy in seahorses. Proceedings of the National Academy of Sciences of the United States of America, 100, 6598–603.
http://dx.doi.org/10.1073/pnas.1131969100Jordan, D.S. & Evermann, B.W. (1903) Descriptions of new genera and species of fishes from the Hawaiian Islands. Bulletin of the US Fish Commission, 22, 161–208.
Jordan, D.S. & Evermann, B.W. (1905) The aquatic resources of the Hawaiian Islands. Part I.--The shore fishes of the Hawaiian Islands, with a general account of the fish fauna. Bulletin of the United States Fish Commisssion, 23, 1–574.
http://dx.doi.org/10.5962/bhl.title.103828Jordan, D.S. & Gilbert, C.H. (1882) Notes on fishes observed about Pensacola, Florida, and Galveston, Texas, with description of new species. Proceedings of the United States National Museum, 5, 241–307.
http://dx.doi.org/10.5479/si.00963801.5-282.241Jordan, D.S. & Richardson, R.E. (1908) Fishes from islands of the Philippine Archipelago. Bulletin of the Bureau of Fisheries, 27, 233–287.
Jordan, D.S. & Snyder, J.O. (1901) Descriptions of nine new species of fishes contained in museums of Japan. Journal of the College of Science, Imperial University of Tokyo, 15, 301–311.
Kaup, J.J. (1853) Uebersicht der lophobranchier. Archiv für Naturgeschichte, 19 (1), 228–230.
http://dx.doi.org/10.5962/bhl.part.9548Kaup, J.J. (1856) Catalogue of Lophobranchiate Fish in the Collection of the British Museum. Woodall and Kinder, London.
Kendrick, A.J. & Hyndes, G.A. (2005) Variations in the dietary compositions of morphologically diverse syngnathid fishes. Environmental Biology of Fishes, 72, 415–427.
http://dx.doi.org/10.1007/s10641-004-2597-yKnowlton, N. (2000) Molecular genetic analyses of species boundaries in the sea. Hydrobiologia, 420, 73–90.
http://dx.doi.org/10.1023/A:1003933603879Kuiter, R. H. (1997) Guide to sea fishes of Australia: A comprehensive reference for divers and fishermen. 2nd ed. French’s Forest, New South Wales, Australia: New Holland Publishers. 434 pp.
Kuiter, R. (2000) Seahorses, pipefishes and their relatives: a comprehensive guide to Syngnathiformes. TMC Publishing, Chorleywood, UK.
Kuiter, R. (2001) Revision of the Australian seahorses of the genus Hippocampus (Syngnathiformes: Syngnathidae) with descriptions of nine new species. Records of the Australian Museum, 53, 293–340.
http://dx.doi.org/10.3853/j.0067-1975.53.2001.1350Kuiter, R. (2003) A new pygmy seahorse (Pisces: Syngnathidae: Hippocampus) from Lord Howe Island. Records of the Australian Museum, 55, 113–116.
http://dx.doi.org/10.3853/j.0067-1975.55.2003.1382Kuiter, R.H. (2009) Seahorses and Their Relatives. Aquatic Photographics, Seaford, Australia.
Kumaravel, K., Ravichandran, S., Balasubramanian, T. & Sonneschein, L. (2012) Seahorses - a source of traditional medicine. Natural Product Research , 26, 2330–2334.
http://dx.doi.org/10.1080/14786419.2012.662650Leach, W.E. (1814) The Zoological Miscellany; Being Descriptions of New, or Interesting Animals. McMillan, London.
Lesson, R.P. (1827) Espèce nouvelle d’Hippocampe. Bulletin des Sciences Naturelles et de Géologie (Férussac), 11, 127–128.
Leysen, H., Roos, G. & Adriaens, D. (2011) Morphological variation in head shape of pipefishes and seahorses in relation to snout length and developmental growth. Journal of Morphology, 272, 1259–70.
http://dx.doi.org/10.1002/jmor.10982Linnaeus, C. (1758) Systema naturæ per regna tria naturæ, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. 10th Editi. Laurentii Salvii, Stockholm.
Lockyear, J.F., Kaiser, H. & Hecht, T. (1997). Studies on the captive breeding of the Knysna seahorse, Hippocampus capensis. Aquarium Sciences and Conservation, 1, 129–136.
Lockyear, J.F., Hecht, T., Kaiser, H. & Teske, P.R. (2006) The distribution and abundance of the endangered Knysna seahorse Hippocampus capensis (Pisces: Syngnathidae) in South African estuaries. African Journal of Aquatic Science, 31, 275–283.
http://dx.doi.org/10.2989/16085910609503897Lourie, S., Foster, S., Cooper, E. & Vincent, A. (2004) A Guide to the identification of Seahorses. Project Seahorse and TRAFFIC North America. University of British Columbia and World Wildlife Fund. Washington, D.C.
Lourie, S. & Kuiter, R. (2008) Three new pygmy seahorse species from Indonesia (Teleostei: Syngnathidae: Hippocampus). Zootaxa, 1963, 54–68.
Lourie, S. & Randall, J. (2003) A new pygmy seahorse, Hippocampus denise (Teleostei Syngnathidae) from the Indo-Pacific. Zoological Studies, 42, 284–291.
Lourie, S., Vincent, A. & Hall, H. (1999) Seahorses: An Identification Guide to the World’s Species and Their Conservation. Project Seahorse, London, UK.
Lourie, S.A. (2004) Phylogeography of Southeast Asian seahorses in a conservation context. PhD thesis, McGill University, Montreal, Canada.
Lourie, S.A., Green, D.M. & Vincent, A.C.J. (2005) Dispersal, habitat differences, and comparative phylogeography of Southeast Asian seahorses (Syngnathidae: Hippocampus). Molecular Ecology, 14, 1073–1094.
http://dx.doi.org/10.1111/j.1365-294X.2005.02464.xLourie, S.A. & Vincent, A.C.J. (2004)a) A marine fish follows Wallace’s Line: the phylogeography of the three-spot seahorse (Hippocampus trimaculatus, Syngnathidae, Teleostei) in Southeast Asia. Journal of Biogeography, 31, 1975–1985.
http://dx.doi.org/10.1111/j.1365-2699.2004.01153.xLourie, S.A. & Vincent, A.C.J. (2004)b) Using biogeography to help set priorities in marine conservation. Conservation Biology, 18, 1004–1020.
http://dx.doi.org/10.1111/j.1523-1739.2004.00137.xMace, G.M. (2004) The role of taxonomy in species conservation. Philosophical Transactions of the Royal Society of London - Series B, Biological Sciences, 359, 711–719.
http://dx.doi.org/10.1098/rstb.2003.1454Maclaine, J. (2015) Hippocampus hippocampus: The saga of the short-snouted seahorse. PULSE: News from the Linnean Society of London, 25, 1–2.
Mariani, S., Griffiths, A.M., Velasco, A., Kappel, K., Jérôme, M., Perez-Martin, R.I., Schröder, U., Verrez-Bagnis, V., Silva, H., Vandamme, S.G., Boufana, B., Mendes, R., Shorten, M., Smith, C., Hankard, E., Hook, S.A., Weymer, A.S., Gunning, D. & Sotelo, C.G. (2015) Low mislabeling rates indicate marked improvements in European seafood market operations. Frontiers in Ecology and the Environment, 13, 536–540.
http://dx.doi.org/10.1890/150119Masonjones, H. & Lewis, S. (2000) Differences in potential reproductive rates of male and female seahorses related to courtship roles. Animal Behaviour, 59, 11–20.
http://dx.doi.org/10.1006/anbe.1999.1269Masuda, H., Amaoka, K., Araga, C., Uyeno, T. & Yoshino, T. (1984) The Fishes of the Japanese Archipelago. 1st ed. Tokai University Press, Tokyo, Japan, 437 pp.
Mayr, E. (1975) Species Concepts and Definitions. In: Grene, M. & Mendelsohn, E. (Eds), Topics in the Philosophy of Biology. Boston Studies in the Philosophy of Science. D. Reidel Publishing Company, Dordrecht, Netherlands, pp. 353–371.
Mee, J.A., Bernatchez, L., Reist, J.D., Rogers, S.M. & Taylor, E.B. (2015) Identifying designatable units for intraspecific conservation prioritization: a hierarchical approach applied to the lake whitefish species complex (Coregonus spp.). Evolutionary Applications, 8, 423–41.
http://dx.doi.org/10.1111/eva.12247Miller, D.J. & Lea, R.N. (1972) Guide to the coastal marine fishes of California. California Fisheries Bulletin, 157, 1–235.
Mobley, K.B., Small, C.M. & Jones, A.G. (2011) The genetics and genomics of Syngnathidae: pipefishes, seahorses and seadragons. Journal of Fish Biology, 78, 1624–46.
http://dx.doi.org/10.1111/j.1095-8649.2011.02967.xMukai, T., Tsuihiji, T., Sato, T. & Morisawa, M. (2000) Mitochondrial DNA divergence in the seahorse, Hippocampus coronatus (Synathioformes: Syngnathidae), collected from Sagami Bay, Japan. Japanese Journal of Ichthyology, 47, 139–143.
Nguyen, V.L. & Do, H.H. (1996) Biological parameters of two exploited seahorse species in a Vietnamese fishery. In Proceedings of the 1st International Conference in Marine Conservation (Hong Kong).
Nickel, J. & Cursons, R. (2012) Genetic diversity and population structure of the pot-belly seahorse Hippocampus abdominalis in New Zealand. New Zealand Journal of Marine and Freshwater Research, 46, 207–218.
http://dx.doi.org/10.1080/00288330.2011.632014Nickel, J.E. (2009) The diversity of Hippocampus abdominalis in New Zealand. MSc thesis, The University of Waikato, Waikato, New Zealand.
Ogilby, J.D. (1908) New or little known fishes in the Queensland Museum. Annals of the Queensland Museum, 9, 1–41.
Otero-Ferrer, F., Herrera, R., López, A., Socorro, J., Molina, L. & Bouza, C. (2015) First records of Hippocampus algiricus in the Canary Islands (north-east Atlantic Ocean) with an observation of hybridization with Hippocampus hippocampus. Journal of Fish Biology, 87, 1080–1089.
http://dx.doi.org/10.1111/jfb.12760Padial, J.M., Miralles, A., De la Riva, I. & Vences, M. (2010) The integrative future of taxonomy. Frontiers in Zoology, 7, 16.
http://dx.doi.org/10.1186/1742-9994-7-16Pajaro, M.G. & Vincent, A.C.J. (2016) The catch and export of the seahorse trade in the Philippines, pre-CITES. Fisheries Centre Working Paper, 2015–102, 27 pp.
Palsbøll, P.J., Bérubé, M. & Allendorf, F.W. (2007) Identification of management units using population genetic data. Trends in Ecology & Evolution 22, 11–16.
http://dx.doi.org/10.1016/j.tree.2006.09.003Perry, G. (1810) Arcana; or The Museum of Natural History: A General Survey of Nature. London.
Peters, W. (1869) Uber neue oder weniger bekannte Fische des Berliner Zoologischen Museums. Monatsberichte der Koniglichen Preussischen Akademie der Wissenschaften zu Berlin, 703–711.
Peters, W. (1877) Übersicht der während der von 1874 bis 1876 unter der Commando des Hrn. Capitän z. S. Freiherrn von Schleinitz ausgeführten Reise S. M. S. Gazelle gesammelten und von der Kaiserlichen Admiralität der Königlichen Akademie der Wissenschaften übersandten Fis. Monatsberichte der Königlichen Preussischen Akademie der Wissenschaften zu Berlin, 1876, 831–854.
Piacentino, G. & Luzzatto, D. (2004) Hippocampus patagonicus sp. nov., nuevo caballito de mar para la Argentina (Pisces, Syngnathiformes). Revista del Museo Argentino de Ciencias Naturales, 6, 339–349.
Popta, C. (1895) Handwritten notes to complete Bleeker’s Atlas Icthyologique des Indes Orientales Neerlandaises. Naturalis Museum, Leiden, Netherlands.
Posnansky, A. (1911) El clima del altiplano y la extension del Lago Titicaca con relacion a Tihuanacu en epocas prehistoricas. La Paz, Bolivia: Tipograpfia Comercial de Ismael Argote.
Project Seahorse (2002) Hippocampus angustus. The IUCN Red List of Threatened Species, 2002, e.T41004A10384184.
Project Seahorse (2003a) Hippocampus borboniensis. The IUCN Red List of Threatened Species, 2003, e.T10061A3158341.
Project Seahorse (2003b) Hippocampus fuscus. The IUCN Red List of Threatened Species, 2003, e.T10068A3159336.
De Queiroz, K. (2007) Species concepts and species delimitation. Systematic Biology, 56, 879–86.
http://dx.doi.org/10.1080/10635150701701083Rafinesque, C.S. (1810) Per le stampe di Sanfilippo Caratteri di alcuni nuovi generi e nuove specie di animali e piante della sicilia, con varie osservazioni sopra i medisimi. Sanfilippo: Palermo, Italy.
http://dx.doi.org/10.5962/bhl.title.104418Randall, J.E. & Lourie, S.A. (2009) Hippocampus tyro, a new seahorse (Gasterosteiformes: Syngnathidae) from the Seychelles. Smithiana Bulletin, 10, 19–21.
Ratnasingham, S. & Hebert, P.D.N. (2007) BOLD: The Barcode of Life Data System (http://www.barcodinglife.org). Molecular Ecology Notes, 7, 355–364.
http://dx.doi.org/10.1111/j.1471-8286.2007.01678.xRatnasingham, S. & Hebert, P.D.N. (2013) A DNA-based registry for all animal species: the barcode index number (BIN) system. PLOS ONE, 8, e66213.
http://dx.doi.org/10.1371/journal.pone.0066213Reiss, H., Hoarau, G., Dickey-Collas, M. & Wolff, W.J. (2009) Genetic population structure of marine fish: mismatch between biological and fisheries management units. Fish and Fisheries, 10, 361–395.
http://dx.doi.org/10.1111/j.1467-2979.2008.00324.xRoos, G., Van Wassenbergh, S., Aerts, P., Herrel, A. & Adriaens, D. (2011) Effects of snout dimensions on the hydrodynamics of suction feeding in juvenile and adult seahorses. Journal of Theoretical Biology, 269, 307–17.
http://dx.doi.org/10.1016/j.jtbi.2010.10.023Saarman, N.P., Louie, K.D. & Hamilton, H. (2010) Genetic differentiation across eastern Pacific oceanographic barriers in the threatened seahorse Hippocampus ingens. Conservation Genetics, 11, 1989–2000.
http://dx.doi.org/10.1007/s10592-010-0092-xSabaj-Pérez, M.H. (2014) Standard Symbolic Codes for Institutional Resource Collections in Herpetology and Ichthyology: an Online Reference. Version 5.0 (22 September 2014) American Society of Ichthyologists and Herpetologists, Washington, DC. Available from: http://www.asih.org (Accessed 27 Jul. 2016)
Sanders, J.G., Cribbs, J.E., Fienberg, H.G., Hulburd, G.C., Katz, L.S. & Palumbi, S.R. (2008) The tip of the tail: Molecular identification of seahorses for sale in apothecary shops and curio stores in California. Conservation Genetics, 9, 65–71.
http://dx.doi.org/10.1007/s10592-007-9308-0Scales, H. (2010) Poseidon’s Steed: The Story of Seahorses, from Myth to Reality. Gotham Books, New York, USA.
Schindler, D.E., Hilborn, R., Chasco, B., Boatright, C.P., Quinn, T.P., Rogers, L.A. & Webster, M.S. (2010) Population diversity and the portfolio effect in an exploited species. Nature, 465, 609–12.
http://dx.doi.org/10.1038/nature09060Schinz, H.R. (1822) Das Thierreich eingetheilt nach dem Bau der Thiere als Grundlage ihrer Naturgeschichte und der vergleichenden Anatomie. 2nd ed. Cotta, Germany.
Shokri, M.R., Gladstone, W. & Jelbart, J. (2009) The effectiveness of seahorses and pipefish (Pisces: Syngnathidae) as a flagship group to evaluate the conservation value of estuarine seagrass beds. Aquatic Conservation: Marine and Freshwater Ecosystems, 19, 588–595.
http://dx.doi.org/10.1002/aqc.1009SAIAB—South African Institute for Aquatic Biodiversity (2016): Specimen-records of preserved specimens in the National Collection of Fishes of South Africa. Vol 1.2. The South African Institute for Aquatic Biodiversity. Dataset/Occurrence. Available from: http://ipt.saiab.ac.za/resource?r=saiab&v=1.2 (accessed 18 April 2016)
Silveira, R.B., Siccha-Ramirez, R., Silva, J.R.S. & Oliveira, C. (2014) Morphological and molecular evidence for the occurrence of three Hippocampus species (Teleostei: Syngnathidae) in Brazil. Zootaxa, 3861 (4), 317–32.
http://dx.doi.org/10.11646/zootaxa.3861.4.2Simberloff, D. (1998) Flagships, umbrellas, and keystones: Is single-species management passé in the landscape era? Biological Conservation, 83, 247–257.
http://dx.doi.org/10.1016/S0006-3207(97)00081-5Simpson, G.G. (1951) The species concept. Evolution: International Journal of Organic Evolution, 5, 285–298.
http://dx.doi.org/10.2307/2405675Sites Jr., J.W. & Marshall, J.C. (2004) Operational criteria for delimiting species. Annual Review of Ecology, Evolution, and Systematics, 35, 199–227.
http://dx.doi.org/10.1146/annurev.ecolsys.35.112202.130128Smith, R.E. (2010) The Biology and Conservation of Gorgonian-Associated Pygmy Seahorses. PhD thesis, University of Queensland, Brisbane, Australia.
Song, H. & Mabuchi, K. (2014) Complete mitochondrial genome sequence of the thorny seahorse Hippocampus histrix (Gasterosteiformes: Syngnathidae). Mitochondrial DNA, 25, 7–8.
http://dx.doi.org/10.3109/19401736.2013.775263Steinke, D., Zemlak, T.S. & Hebert, P.D.N. (2009) Barcoding nemo: DNA-based identifications for the ornamental fish trade. PLOS ONE, 4, e6300.
http://dx.doi.org/10.1371/journal.pone.0006300Stölting, K.N. & Wilson, A.B. (2007) Male pregnancy in seahorses and pipefish: beyond the mammalian model. BioEssays, 29, 884–96.
http://dx.doi.org/10.1002/bies.20626Szabó, Z., Kimokeo, B.K., Toonen, R.J. & Randall, J.E. (2011) On the status of the Hawaiian seahorses Hippocampus hilonis, H. histrix and H. fisheri (Syngnathidae). Marine Biology Research, 7, 701–709.
http://dx.doi.org/10.1080/17451000.2011.558096Temminck, C.J. & Schlegel, H. (1850) Pisces. In: Fauna Japonica, sive descriptio animalium quae in itinere per Japoniam suscepto annis 1823-30 collegit, notis observationibus et adumbrationibus illustravit P. F. de Siebold, pp. 270–324.
Teske, P.R. & Beheregaray, L.B. (2009) Evolution of seahorses’ upright posture was linked to Oligocene expansion of seagrass habitats. Biology letters, 5, 521–3.
http://dx.doi.org/10.1098/rsbl.2009.0152Teske, P.R., Cherry, M.I. & Matthee, C.A. (2003) Population genetics of the endangered Knysna seahorse, Hippocampus capensis. Molecular Ecology, 12, 1703–1715.
http://dx.doi.org/10.1046/j.1365-294X.2003.01852.xTeske, P.R., Cherry, M.I. & Matthee, C.A. (2004) The evolutionary history of seahorses (Syngnathidae: Hippocampus): molecular data suggest a West Pacific origin and two invasions of the Atlantic Ocean. Molecular Phylogenetics and Evolution, 30, 273–286.
http://dx.doi.org/10.1016/S1055-7903(03)00214-8Teske, P.R., Hamilton, H., Matthee, C.A. & Barker, N.P. (2007a) Signatures of seaway closures and founder dispersal in the phylogeny of a circumglobally distributed seahorse lineage. BMC Evolutionary Biology, 7, 138.
http://dx.doi.org/10.1186/1471-2148-7-138Teske, P.R., Hamilton, H., Palsboll, P.J., Choo, C.K., Gabr, H., Lourie, S.A., Santos, M., Sreepada, R.A., Cherry, M.I. & Matthee, C.A. (2005) Molecular evidence for long-distance colonization in an Indo-Pacific seahorse lineage. Marine Ecology Progress Series, 286, 249–260.
http://dx.doi.org/10.3354/meps286249Teske, P.R., Lockyear, J.F., Hecht, T. & Kaiser, H. (2007b) Does the endangered Knysna seahorse, Hippocampus capensis, have a preference for aquatic vegetation type, cover or height? African Zoology, 42, 23–30.
http://dx.doi.org/10.3377/1562-7020(2007)42[23:DTEKSH]2.0.CO;2Teske, P.R., Lourie, S.A., Matthee, C.A. & Green, D.M. (2007c) Hippocampus queenslandicus Horne, 2001—a new seahorse species or yet another synonym? Australian Journal of Zoology, 55, 139–145.
http://dx.doi.org/10.1071/ZO07021Turner, G.F. (1999) What is a fish species? Reviews in Fish Biology and Fisheries, 9, 281–297.
http://dx.doi.org/10.1023/A:1008903228512UNEP-WCMC (2015) CITES Trade Database. Available from: http://trade.cites.org (accessed 30 Oct. 2015)
UNEP-WCMC (Comps.) (2015) The Checklist of CITES Species Website. CITES Secretariat, Geneva, Switzerland. Compiled by UNEP-WCMC, Cambridge, UK. Available from: checklist.cites.org (accessed 12 April 2016)
Vari, R. (1982) The seahorses (subfamily Hippocampinae). In: Fishes of the Western North Atlantic. Sears Foundation for Marine Research, Yale University, New Haven, Connecticut, pp. 178–193.
Vasil’Eva, E.D. (2007) Seahorse species (genus Hippocampus, Pisces) described by C. Linné. Folia Zoologica 56, 319–327.
Vincent, A.C.J., Foster, S.J. & Koldewey, H.J. (2011) Conservation and management of seahorses and other Syngnathidae. Journal of Fish Biology 78, 1681–1724.
http://dx.doi.org/10.1111/j.1095-8649.2011.03003.xVincent, A.C.J., Sadovy de Mitcheson, Y.J., Fowler, S.L. & Lieberman, S. (2014) The role of CITES in the conservation of marine fishes subject to international trade. Fish and Fisheries, 15, 563–592.
http://dx.doi.org/10.1111/faf.12035Wang, X., Zhang, Y., Zhang, H., Meng, T. & Lin, Q. (2016) Complete mitochondrial genome sequence of the longsnout seahorse Hippocampus reidi (Ginsburg, 1933; Gasterosteiformes: Syngnathidae). Mitochondrial DNA, 27, 1401–1402.
http://dx.doi.org/10.3109/19401736.2014.947600Waples, R.S. (2008) Evolutionarily significant units, distinct population segments, and the Endangered Species Act: Reply to Pennock and Dimmick. Conservation Biology, 12, 718–721.
http://dx.doi.org/10.1111/j.1523-1739.1998.97524.xWard, R.D., Hanner, R. & Hebert, P.D.N. (2009) The campaign to DNA barcode all fishes, FISH-BOL. Journal of Fish Biology, 74, 329–56.
http://dx.doi.org/10.1111/j.1095-8649.2008.02080.xWeber, M. (1913) Die Fische der Siboga-Expedition. E. J. Brill, Leiden.
Wheeler, A. (1985) The Linnaean fish collection in the Linnean Society of London. Zoological Journal of the Linnean Society, 84, 1–76.
http://dx.doi.org/10.1111/j.1096-3642.1985.tb01716.xWheeler, Q. & Meier, R.( Eds.) (2000) Species concepts and phylogenetic theory: a debate. Columbia University Press, New York.
Whitley, G. & Allen, J. (1958) The seahorse and its relatives. Griffin Press, Melbourne.
Whitley, G.P. (1964) Fishes from the Coral Sea and the Swain Reefs. Records of the Australian Museum, 26, 145–195.
http://dx.doi.org/10.3853/j.0067-1975.26.1964.673Whitley, G.P. (1970) Bargibant’s Sea-horse from New Caledonia. Proceedings of the Linnean Society of New South Wales 94 (3), 294.
Wikipedia (2016) Wikipedia. Available from: www.wikipedia.org (accessed 12 Apr. 2016)
Will, K.W. & Rubinoff, D. (2004) Myth of the molecule: DNA barcodes for species cannot replace morphology for identification and classification. Cladistics, 20, 47–55.
http://dx.doi.org/10.1111/j.1096-0031.2003.00008.xWilson, A.B., Ahnesjo, I., Vincent, A.C.J. & Meyer, A. (2003) The dynamics of male brooding, mating patterns, and sex roles in pipefishes and seahorses (family Syngnathidae). Evolution, 57, 1374–1386.
http://dx.doi.org/10.1111/j.0014-3820.2003.tb00345.xWilson, A.B. & Orr, J.W. (2011) The evolutionary origins of Syngnathidae: pipefishes and seahorses. Journal of Fish Biology, 78, 1603–1623.
http://dx.doi.org/10.1111/j.1095-8649.2011.02988.xWoodall, L. (2009) Population Genetics and Mating Systems of European Seahorses Hippocampus guttulatus and Hippocampus hippocampus. PhD thesis. University of London.
Woodall, L.C., Koldewey, H.J., Boehm, J.T. & Shaw, P.W. (2015) Past and present drivers of population structure in a small coastal fish, the European long snouted seahorse Hippocampus guttulatus. Conservation Genetics, 16, 1139–1153.
http://dx.doi.org/10.1007/s10592-015-0728-yWoodall, L.C., Koldewey, H.J., Santos, S.V & Shaw, P.W. (2009) First occurrence of the lined seahorse Hippocampus erectus in the eastern Atlantic Ocean. Journal of Fish Biology, 75, 1505–12.
http://dx.doi.org/10.1111/j.1095-8649.2009.02371.xWoodall, L.C., Koldewey, H.J. & Shaw, P.W. (2011) Historical and contemporary population genetic connectivity of the European short-snouted seahorse Hippocampus hippocampus and implications for management. Journal of Fish Biology, 78, 1738–56.
http://dx.doi.org/10.1111/j.1095-8649.2011.02974.xYasué, M., Nellas, A., Panes, H. & Vincent, A.C.J. (2015) Monitoring landed seahorse catch in a changing policy environment. Endangered Species Research, 27, 95–111.
http://dx.doi.org/10.3354/esr00643Yearsley, G.K., Last, P.R. & Hoese, D.F. (Eds.) (2006) Standard names of Australian Fishes. CSIRO Marine and Atmospheric Research Paper 009, 66 pp.
Zachos, F.E. (2013) Taxonomy: Species splitting puts conservation at risk. Nature, 494, 35.
http://dx.doi.org/10.1038/494035cZhang, Y., Pham, N.K., Zhang, H., Lin, J. & Lin, Q. (2014) Genetic variations in two seahorse species (Hippocampus mohnikei and Hippocampus trimaculatus): evidence for middle Pleistocene population expansion. PLOS ONE, 9, e105494.
http://dx.doi.org/10.1371/journal.pone.0105494Zhang, Y., Zhang, H., Lin, Q. & Huang, L. (2015) Complete mitochondrial genome sequence of the lined seahorse Hippocampus erectus Perry, 1810 (Gasterosteiformes: Syngnathidae). Mitochondrial DNA, 26, 659–660.
http://dx.doi.org/10.3109/19401736.2013.840595