Environmental Biology of Fishes

, Volume 96, Issue 12, pp 1399–1405 | Cite as

Seahorse fingerprints: a new individual identification technique

  • Natalie V. Freret-MeurerEmail author
  • José V. Andreata
  • Maria Alice S. Alves


Individual identification is particularly important for ethological studies and sampling design. Previous studies have developed various types of marking by tags and chemical marks, but these methods involve significant manipulation of the individuals. Other studies have reported natural marks as an efficient method for individual recognition. Our study aims to elucidate a new method for natural mark identification of seahorses, which we tested with the endangered Brazilian seahorse Hippocampus reidi. We avoid pseudoreplication by recognizing individuals. Seahorses have a hard bony structure on the top of their heads called the coronet, which has a different shape for each individual, corresponding to a fingerprint. We tagged seahorses in the field with collar tags and photographed their coronets. After two days, we identified seahorses by their photographs and verified their identification with the collar tags. We correctly identified all individuals by fingerprint identification. Although this method was only tested with adults, we suggest that it applies to seahorses in general, as all species possess the coronet structure.


Syngnathidae New method Natural marks 



We thank Bruno Meurer and Oliver Pereira for their assistance with the fieldwork. This work was supported by CAPES, Coordenação de Aperfeiçoamento de Pessoal de Nível Superior at the time of the field research. We also thank CNPq (proc. 308792/2009-2) and FAPERJ (proc. E-26/102868/2008 for the research grant to one the authors (M.A.S.A.) while writing this paper.


  1. Arntzen JW, Goudie IBJ, Halley J, Jehle R (2004) Cost comparison of marking techniques in long-term population studies: PIT-tags versus pattern maps. Amph–Rept 25:305–315Google Scholar
  2. Bell EM, Lockyear JF, Mcpherson ADM, Vincent ACJ (2003) First field studies of an endangered South African seahorse Hippocampus capensis. Environ Biol Fish 67:35–46CrossRefGoogle Scholar
  3. Block BA, Teo SLH, Walli A, Boustany A, Stokesbury MJW, Farwell CJ, Weng KC, Dewar H, Williams TD (2005) Electronic tagging and population structure of Atlantic bluefin tuna. Nature 434:1121–1127PubMedCrossRefGoogle Scholar
  4. Calambokidis J, Barlow J, Ford JK, Chandler TE, Douglas AB (2009) Insights into the population structure of blue whales in the Eastern North Pacific from recent sightings and photographic identification. Mar Mam Sci. doi: 10.1111/j.1748-7692.2009.00298
  5. Caldwell IR, Correia M, Palma J, Vincent ACJ (2011) Advances in tagging syngnathids, with the effects of dummy tags on behaviour of Hippocampus guttulatus. J Fish Biol 78:1769–1785PubMedCrossRefGoogle Scholar
  6. Curtis JMR (2006) A case of mistaken identity: skin filaments are unreliable for identifying Hippocampus guttulatus and Hippocampus hippocampus. J Fish Biol 69:1855–1859CrossRefGoogle Scholar
  7. DeRoche SE (1963) Slowed growth of lake trout following tagging. Trans Am Fish Soc 92:185–186CrossRefGoogle Scholar
  8. Dobson H, Smith RF (2000) What is stress, and how does it affect reproduction? Anim Reprod Sci 60–61:743–752PubMedCrossRefGoogle Scholar
  9. Eames M, Hino MK (1983) An evaluation of four tags suitable for marking juvenile chinook salmon. Trans Am Fish Soc 112:464–468CrossRefGoogle Scholar
  10. Fiedler W (2009) New technologies for monitoring bird migration and behavior. Ringing Migr 24:175–179CrossRefGoogle Scholar
  11. Foster SJ, Vincent ACJ (2004) Life history and ecology of seahorses: implications for conservation and management. J Fish Biol 64:1–61Google Scholar
  12. Freret-meurer NV, Andreata JV (2008) Field studies of a Brazilian seahorse population, Hippocampus reid Ginsburg, 1933. Braz Arch Biol Technol 51(4):743–751CrossRefGoogle Scholar
  13. Freret-meurer NV, Andreata JV, Alves MAS (2009) Padrão de atividade diurna do cavalo-marinho Hippocampus reidi no estado do Rio de Janeiro. Oecol Bras 13:89–98Google Scholar
  14. Freret-Meurer NV, Andreata JV, Alves MAS (2012) Activity rate of the seahorse Hippocampus reidi Ginsburg, 1933 (Syngnathidae). Acta Ethol 15(2):221–227Google Scholar
  15. Friday N, Smith TD (2000) Measurement of photographic quality and individual distinctiveness for the photographic identification of humpback whales, Megaptera novaeangliae. Mar Mam Sci 16(2):355–374CrossRefGoogle Scholar
  16. Giklinson AK, Pearson HC, Weltz F, Davis RW (2007) Photo-identification of sea otters using nose scars. J Wild-life Man 71(6):2045–2051CrossRefGoogle Scholar
  17. Glockner DA, Venus SC (1983) Identification, growth rate, and behaviour of humpback whale (Megaptera novaeangliae) cows and calves in the waters off Maui, Hawaii. In: Payne R (ed) Communication and behavior of whales. Westview Press, Colorado, pp 223–258Google Scholar
  18. Horne ML (2001) A new seahorse species (Syngnathidae: Hippocampus) from the Great Barrier Reef. Rec Aust Mus 52:243–246CrossRefGoogle Scholar
  19. Hussey NE, McCarthy ID, Dudley SFJ, Mann BQ (2009) Nursery grounds, movement patterns and growth rates of dusky sharks, Carcharhinus obscurus: a long-term tag and release study in South African waters. Mar Fresh Res 60:571–583CrossRefGoogle Scholar
  20. Hutchings JA, Gerber L (2002) Sex-biased dispersal in a salmonid fish. Proc R Soc Lond 269:2487–2493CrossRefGoogle Scholar
  21. Iversen RTB (1962) Food of albacore tuna, Tunnus germo (Lacepede), in the central and northeastern Pacific. Fish Bull 62:459–481Google Scholar
  22. Jensen AC (1967) Effects of tagging on the growth of cod. Trans Am Fish Soc 96:185–186CrossRefGoogle Scholar
  23. Kuiter RH (2001) Revision of the Australian seahorses genus Hippocampus (Syngnathiformes: Syngnathidae) with a description of nine new species. Rec Aust Mus 53:293–340CrossRefGoogle Scholar
  24. Kuiter RH (2003) A new pigmy seahorse (Pisces: Syngnathidae: Hippocampus) from Lord Howe Island. Rec Aust Mus 55:113–116CrossRefGoogle Scholar
  25. Le Cheminant JM (2000) An investigation to establish the suitability of opalithplattchen (bee tags), Floy and visible implant fluorescent elastomer (VIFE) tagging systems for marking the Knysna seashores, Hippocampus capensis. Dissertation, Bournemouth UniversityGoogle Scholar
  26. Lourie SA, Vincent ACJ, Hall HJ (1999) Seahorses: An identification guide to the world’s species and their conservation. Project Seahorse, LondonGoogle Scholar
  27. Lourie SA, Foster SJ, Cooper EWT, Vincent ACJ (2004) A guide to the identification of seahorses. Project Seahorse and TRAFFIC North America. Washington DCGoogle Scholar
  28. Martin-Smith KM (2011) Photo-identification of individual weedy seadragons Phyllopteryx taeniolatus and its application in estimating population dynamics. J Fish Biol 78:1757–1768PubMedCrossRefGoogle Scholar
  29. Martin-Smith KM, Vincent ACJ (2005) Seahorse declines in the Derwent estuary, Tasmania in the absence of fishing pressure. Biol Conserv 123:533–545CrossRefGoogle Scholar
  30. Mazzoni R, Bizerril CRSF, Buckup PA, Caetano MFO, Figueiredo CA, Menezes NA, Nunan GW, Tanizaki-Fonseca K (2000) Peixes. In: Bergallo HG, Rocha CFD, Alves MAS, Van Sluys M (eds) A Fauna ameaçada de extinção do Estado do Rio de Janeiro, Editora da Universidade do Estado do Rio de Janeiro, Rio de Janeiro, pp 63–73Google Scholar
  31. McGregor RL, Bender DJ, Fahrig L (2008) Do small mammals avoid roads because of the traffic? J Appl Ecol 45:117–123CrossRefGoogle Scholar
  32. Moreau M, Vincent ACJ (2004) Social structure and space use in a wild population of the Australian short-headed seahorse Hippocampus breviceps Peters, 1869. Mar Fresh Res 55:231–239CrossRefGoogle Scholar
  33. Morgan S, Martin-Smith KM (2004) Selected techniques for tagging seahorses. Tech Rep Ser 6Google Scholar
  34. Nelson JS (1994) Fishes of the world. Wiley, New YorkGoogle Scholar
  35. Payne R, Brazier O, Dorsey EM, Perkins JS, Rowntree VJ, Titus A (1983) External features in southern right whales (Eubalaena australis) and their use in identifying individuals. In: Payne (ed) Communication and behavior of whales. Westview Press, Colorado, pp 371–445Google Scholar
  36. Perante NC, Pajaro MG, Meeuwig JJ, Vincent ACJ (2002) Biology of a seahorse species, Hippocampus comes in the central Philippines. J Fish Biol 60:821–837CrossRefGoogle Scholar
  37. Petersen JCB (1972) An identification system for zebra (Equus burchelli, Gray). East Afr Wildlife J 10:59–63CrossRefGoogle Scholar
  38. Silveira RB (2005) Dinâmica populacional do cavalo-marinho Hippocampus reidi (Syngnathidae) no manguezal de Maracaípe, Ipojuca, PE.PhD Thesis, Universidade Católica do Rio Grande do SulGoogle Scholar
  39. Teo SLH, Sandstrom PT, Chapman ED, Null RE, Brown K, Klimley AP, Block BA (2005) Archival and acoustic tags reveal the post-spawning migrations, diving behavior, and thermal habitat of hatchery-origin Sacramento River steelhead kelts (Oncorhynchus mykiss). Environ Biol Fish. doi: 10.1007/s10641-011-9938-4
  40. Titus RG, Vanicek CD (1988) Comparative hooking mortality of lure-caught lahontan cutthroat trout at Heenan Lake, California. Cal Fish Game 74:218–225Google Scholar
  41. Vincent ACJ, Giles BG (2003) Correlates of reproductive success in a wild population of Hippocampus whitei. J Fish Biol 63:344–355CrossRefGoogle Scholar
  42. Vincent ACJ, Sadler LM (1995) Faithful pair bonds in wild seahorses, Hippocampus whitei. Anim Behav 50:1557–1569CrossRefGoogle Scholar
  43. Vincent ACJ, Evans KL, Marsden AD (2005) Home range behaviour of the monogamous Australian seahorse, Hippocampus withei. Environ Biol Fish 72:1–12CrossRefGoogle Scholar
  44. Vincent ACJ, Foster SJ, Koldewey HJ (2011) Conservation and management of seahorses and other Syngnathidae. J Fish Biol 78(6):1681–1724PubMedCrossRefGoogle Scholar
  45. Woods CWC, Martin-Smith KM (2004) Visible implant fluorescent Elastomer tagging of the big-bellied seahorse, Hippocampus abdominalis. Fish Res 66:363–371CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media Dordrecht 2013

Authors and Affiliations

  • Natalie V. Freret-Meurer
    • 1
    • 2
    Email author
  • José V. Andreata
    • 2
  • Maria Alice S. Alves
    • 1
  1. 1.Departamento de Ecologia, Instituto de Biologia Roberto Alcantara GomesUniversidade do Estado do Rio de JaneiroRio de JaneiroBrazil
  2. 2.Laboratório de Ictiologia, Instituto de Ciências Biológicas e AmbientaisUniversidade Santa ÚrsulaRio de JaneiroBrazil

Personalised recommendations