Reoccurrence of the Pacific Seahorse,
Hippocampus Ingens, in San Diego Bay
Robert Snodgrass, Former Aquarium Curator
Reprinted from California Fish and Game 74 (4): 236-248
Originally published in 1988
The Pacific seahorse, Hippocampus ingens, has reappeared in San Diego Bay. Hippocampus ingens is the only species of seahorse in the eastern Pacific and is one of the largest seahorses known, reaching a maximum length of 12 in. (30 cm) (Miller and Lea 1972). The normal distributional range of the Pacific seahorse is from central Baja California to northern Peru (Hubbs and Hinton 1963). Although common, especially in bays over this geographic area, it has rarely been reported in California waters (Starks and Morris 1907, Hubbs and Hinton 1963, Miller and Lea 1972, Eschmeyer and Herald 1983). There have been only nine specimens reported from the San Diego area since the mid 1800's (five in 1857, one in 1872, one in 1880, one in 1962, and one in 1958 or 1959) (Hubbs and Hinton 1963). A survey of San Diego Bay eelgrass beds in 1980-81 did not reveal any seahorses (Hoffman 1986). Reported here, are additional records collected recently from San Diego Bay and adjacent waters documenting the return of Hippocampus ingens to the San Diego Bay area.
Since 1984, there has been an apparent resurgence of seahorses in San Diego Bay as accounted for by fishermen and divers. Twenty-two records have been tabulated (Table I ). The first of these seahorses was collected on 16 August 1984, by Jason Campbell while playing in the surf at Mission Beach. It was donated the same day to the Scripps Aquarium. In November 1984, while otter trawling immediately south of Coronado Cays at a depth of 4 m, we (ATJ and PD) collected a second seahorse. Six months later (3 May 1985), a specimen was taken in Mission Bay by a diver under his boat at Marina Village near the ocean channel. At this time, a report was received at Scripps Aquarium of a dead seahorse on a beach in Mission Bay. The next specimen was caught a month later when a seahorse wrapped its tail around the finger of a diver working in zero visibility at one of the Naval docks in San Diego Bay.