Hippocampus fisheri, commonly known as Fisher's seahorse, or the Hawaiian seahorse, is a species of fish of the family Syngnathidae. It is known from the Hawaiian Islands, although previous misidentifications indicated species occurrences in Australia and New Caledonia. Habitat preferences are unknown, but it has been found far away from shore and at depths greater than 100 metres (330 ft). Feeding habits are also unknown, but individuals are expected to feed on small crustaceans similar to other seahorses. They are also expected to be ovoviviparous, with males carrying eggs in a brood pouch before giving birth to live young. Individuals can grow to lengths of 8 centimetres (3.1 in). The specific name and the common name honour "Walter V. Fisher" of Stanford University.
- Pollom, R. (2017). "Hippocampus fisheri". The IUCN Red List of Threatened Species. 2017: e.T41009A54908481. doi:10.2305/IUCN.UK.2017-3.RLTS.T41009A54908481.en.
- Lourie, S.A., A.C.J. Vincent and H.J. Hall, 1999. Seahorses: an identification guide to the world's species and their conservation. Project Seahorse, London. p. 214
- D.S. Jordan; B.W. Evermann (1903). "Descriptions of new genera and species of fishes from the Hawaiian Islands" (PDF). Bulletin of the U. S. Fish Commission. 22 (1902): 161–208.