H. hippocampus (Linnaeus 1758) English common names. Short-snouted Seahorse. Synonyms. Gasterosteus equus Cabrera, Pérez, and Haenseler 1817, Syngnathus hippocampus Linnaeus 1758, H. heptagonus Rafinesque 1810, H. antiquorum Leach 1814, H. vulgaris Cloquet 1821, H. brevirostris Schinz 1822, H. antiquus Risso 1827, H. europaeus Ginsburg 1937; H. pentagonus Rafinesque 1810. Distribution. Algeria, Albania, Azores, Croatia, France, The Gambia, Greece, Guinea, Guinea-Bissau, Italy, Malta, Montenegro, Netherlands, Portugal, Senegal, Slovenia, Spain (including the Canary Islands), Turkey, UK, Western Sahara. Neotype: BMNH 1872.2.6.3 (but see notes about Linnaeus’ specimens). Type locality. Spain / Portugal, eastern Atlantic. Notes. Linnaeus had two seahorses in his collection, one of which is the European Short-snouted Seahorse, the other is a distinctly spiny species of unknown identity (SL pers. obs., Maclaine 2015). Linnaeus himself made no distinction between different species of seahorse and gave them only a single name, Syngnathus hippocampus. This species name has been used extensively with the revised generic name for seahorses— Hippocampus) for the Short- Snouted Seahorse over the years, and is consistent with one of Linneaus’ specimens. Vasil’Eva (2007) however, suggests the use of H. hippocampus for the long-snouted European seahorse based on (some of) the meristic data in Linnaeus’ original descriptions. This action would be extremely disruptive to European seahorse nomenclature. We follow CF (Eschmeyer & Fricke 2016) and Maclaine (2015) in recommending that Vasil’Eva’s publication, its neotype designation, and its nomenclatural conclusions be suppressed. Hippocampus hippocampus consists of three distinct genetic units (921 bp cyt b and CR) in the English Channel/ Bay of Biscay, the Mediterranean/Atlantic Europe, and West Africa (Woodall et al. 2011). Hippocampus europaeus does not exhibit meristic or morphological characteristics that distinguish it (Appendix F). The average distance among the populations in the Mediterranean and Atlantic Europe is 0.89%, while the average distance of the West African populations is 1.90% from the above populations (Woodall et al. 2011), and these do tend to have distinctively large coronets (Lourie et al. 1999).

Published as part of Sara A. Lourie, Riley A. Pollom & Sarah J. Foster, 2016, A global revision of the Seahorses Hippocampus Rafinesque 1810 (Actinopterygii: Syngnathiformes): Taxonomy and biogeography with recommendations for further research, pp. 1-66 in Zootaxa 4146 (1) on page 27, DOI: 10.11646/zootaxa.4146.1.1, http://zenodo.org/record/268078