Hippocampus erectus 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Actinopterygii Syngnathiformes Syngnathidae

Scientific Name: Hippocampus erectus Perry, 1810
Regional Assessments:
Common Name(s):
English Lined Seahorse, Horsefish, Northern Seahorse, Northern Seahorse, Spotted Seahorse
French Hippocampe Rayé
Spanish Caballito de mar, Caballito erecto, Caballito estriado, Caballito punteado
Hippocampus fascicularis Kaup, 1856
Hippocampus laevicaudatus Kaup, 1856
Hippocampus marginalis Kaup, 1856
Hippocampus brunneus Bean, 1906
Hippocampus hudsonius DeKay, 1842
Hippocampus kincaidi Townsend and Barbour, 1906
Hippocampus punctulatus Guichenot, 1853
Hippocampus stylifer Jordan and Gilbert, 1882
Hippocampus tetragonus (Mitchill, 1814)
Hippocampus villosus Günther, 1880
Syngnathus tetragonus Mitchill, 1814
Syngnathus caballus Larrañaga, 1923
Taxonomic Source(s): Lourie, S.A., Pollom, R.A. and Foster, S.J. 2016. A global revision of the seahorses Hippocampus Rafinesque 1810 (Actinopterygii: Syngnathiformes): Taxonomy and biogeography with recommendations for future research. Zootaxa 4146(1): 1-66.

Assessment Information [top]

Red List Category & Criteria: Vulnerable A2cd ver 3.1
Year Published: 2017
Date Assessed: 2016-10-03
Assessor(s): Pollom, R.
Reviewer(s): Ralph, G.
Hippocampus erectus is a coastal seahorse species that inhabits a wide variety of habitats from Nova Scotia, Canada, to Brazil, including the Gulf of Mexico and Caribbean Sea. The species is threatened by being caught as bycatch in trawl fisheries and/or by being targeted for use in the aquarium trade, and by ongoing habitat degradation and loss. It is traded for traditional medicines, curios, and aquarium use. It is suspected through fisher interviews in the late 1990s and early 2000s that the species had undergone a decline of at least 30% over the previous 10 years. It is suspected that these threats are likely contributing to further declines, and thus that the previous estimate is still applicable. No further studies on population size or trends or on threats to the species have been undertaken since the previous assessment. Therefore this species is listed as Vulnerable under criterion A2cd.
Previously published Red List assessments:

Geographic Range [top]

Range Description:Hippocampus erectus is distributed in the western Atlantic from the southern tip of Nova Scotia, Canada, south along the east coast of the United States, Bermuda, the Bahamas, and throughout the Gulf of Mexico and Caribbean Sea to Bahia, Brazil (Silveira et al. 2014, Boehm et al. 2015). It has also been collected from Banco Acores (Azores Archipelago) in the eastern Atlantic, although it's not clear whether there is an established population there (Woodall et al. 2009). Its depth range is 0-100 m (Freret-Meurer and Andreata 2011).
Countries occurrence:
Bahamas; Belize; Bermuda; Brazil; Costa Rica; Cuba; Guatemala; Haiti; Honduras; Mexico (Veracruz, Yucatán); Nicaragua; Panama; Saint Kitts and Nevis; Suriname; United States (Connecticut, Delaware, Florida, Georgia, Louisiana, Maryland, New Jersey, New York, North Carolina, Rhode Island, South Carolina, Virginia); Venezuela, Bolivarian Republic of
Present - origin uncertain:
Canada (Nova Scotia)
FAO Marine Fishing Areas:
Present - origin uncertain:
Atlantic – western central; Atlantic – southwest; Atlantic – northwest
Additional data:
Continuing decline in area of occupancy (AOO):Unknown
Extreme fluctuations in area of occupancy (AOO):UnknownEstimated extent of occurrence (EOO) - km2:
Continuing decline in extent of occurrence (EOO):UnknownExtreme fluctuations in extent of occurrence (EOO):Unknown
Continuing decline in number of locations:Unknown
Extreme fluctuations in the number of locations:Unknown
Lower depth limit (metres):100
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:To date there have been no dedicated in situ surveys or population estimates for Hippocampus erectus. 

Project Seahorse trade surveys conducted between 2000–2001 indicated that seahorse numbers in the wild appear to have declined in the Western Atlantic (Caribbean and Gulf of Mexico), with fishers reporting decreases in catch of seahorses (proportion of declines that can be attributed to H. erectus is unknown). On the coast of Mexico 21/29 fishers in five locations reported declines in seahorses due to the shrimp trawl fishery. Of the 14 fishers who provided quantified catch estimates, eight estimated declines between 75–90% in the past 10–30 years (Baum et al. 2003). In Brazil 25/29 fishers surveyed reported declines in seahorse catches due to heavy fishing pressures (I. Rosa, unpublished data). In Honduras 70% of interviewed fishers (n=9) believed there has been a decline in abundance (Baum and Vincent 2005). In all cases other fishers indicated stability in the seahorse population.

While we recognise that these surveys and reported population declines are outdated and do not encompass the global range of H. erectus, more comprehensive, recent studies of the population are not available. Given that the major threats (exploitation and habitat degradation) have not ceased, and may be accelerating, we suspect that the previous global estimate of at least a 30% decline over 10 years (three generation lengths) is still applicable.

This species has been listed as Vulnerable at the regional scale based on population declines in Brazil and the Gulf of Mexico.

Current Population Trend:Decreasing
Additional data:
Continuing decline of mature individuals:Yes
Extreme fluctuations:UnknownPopulation severely fragmented:Unknown
Continuing decline in subpopulations:Unknown
Extreme fluctuations in subpopulations:UnknownAll individuals in one subpopulation:No

Habitat and Ecology [top]

Habitat and Ecology:Hippocampus erectus occurs in water up to 100 m (Freret-Meurer and Andreata 2011), and is associated with aquatic vegetation such as mangroves (mostly Rhizophora mangle and Avicennia sp.), Caulerpa spp., Carijoa sp., seagrass (Thalassia testudinum, Halophila sp.), as well as coral, rocky and oyster reef habitats, floating Sargassum, and sponges (Fish and Mowbray 1970, Lieske and Myers 1994,  McAllister 1990 in Lourie et al. 1999, Dias et al. 2002, Hare et al. 2006). Hippocampus erectus can be found at the surface and bottom of both shallow water and deeper areas of channels in bays, along beaches, in or near salt marshes, anchialine lakes, and over oyster beds and weed-covered banks (Hardy 1978, Rose et al. 2016). In Brazil it has been found in water with a salinity of 45% (Dias et al. 2002).   Little is known about their feeding, but they likely have diets similar to those exhibited by other seahorses which include mysids, amphipods, copepods, and gammarid shrimps (Woods 2002, Kendrick and Hyndes 2005, Felicio et al. 2006, Kitsos et al. 2008, Yip et al. 2015). 
Hippocampus erectus is ovoviviparous, and males brood the young in a pouch prior to giving live birth (Foster and Vincent 2004). The maximum size for the species is 18.5cm; the maximum reported height at onset of sexual maturity is 5.6 cm (Baum et al. 2003). Both males and females are fully mature at 12 cm, and the average brood size for this species is 250 to 300 eggs (although larger males can produce over 1200)(Fritzsche 2002, Baum et al. 2003, Dunham 2010). Hippocampus erectus matures during the first reproductive season after birth at six to twelve months of age, and has a gestation period of 20–21 days, varying with water temperature (Lourie et al. 1999). The egg diameter is 0.15 cm and the young approximately 0.49cm long at birth (Dunham 2010). The reproductive period for this species is apparently from May to October. The number of eggs/embryos inside the brood pouch of males with a total length ranging from 8cm to 12.6cm, from 97 to 1,552; number of prehydrated oocytes in females with a total length ranging from 6cm to 12.3cm, from 90 to 1,313. Newborns are released by ejection from the brood pouch by body contortions and pumping action of the pouch (Teixeira and Musick 2001). 

This species is known to develop elaborate skin fronds and males have proportionally longer tails than do females (Baum et al. 2003, Lourie et al. 2004).

This species may be particularly susceptible to decline.   All seahorse species have vital parental care, and many species studied to date have high site fidelity (Perante et al. 2002, Vincent et al. 2005), highly structured social behaviour (Vincent and Sadler 1995), and relatively sparse distributions (Lourie et al. 1999).
Generation Length (years):1
Movement patterns:Not a Migrant

Use and Trade [top]

Use and Trade: Hippocampus erectus is an important species in aquarium and medicinal trades (Zhang et al. 2010). This species is used in domestic folk medicine and souvenir trades, and domestic and international aquarium trades in Mexico, Brazil, and for domestic trades in Central America. Hippocampus erectus is also taken as by catch in shrimp trawl fisheries in the USA, Mexico, and Central America, some of which is retained for export for use in the Traditional Chinese Medicine trade (Dias et al. 2002). This species has been reared successfully in captivity; this has in part been the result of increasing culture efforts since all 33 recognised Hippocampus spp. species were listed on Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora, due to over-exploitation of the wild populations to meet growing demand in the Chinese medicine and ornamental market (Vincent 1996, Lourie et al. 1999, Zhang et al. 2011).    
Hippocampus erectus is one of more than ten seahorse species to have been successfully reared in captivity and is recognised as a good candidate for commercial aquaculture (Barletta and Correa 1989, Lin et al. 2008, Zhang et al. 2010). Seahorses also provide more tractable study taxa than many other small fish species due to their limited movement and site fidelity (Foster and Vincent 2005). About 95% of the seahorses in trade are used in TCM; as China’s population continues to grow rapidly, the demand for syngnathid products has followed (West 2012).  
Between January 1995 and November 2000, there were 12,586 specimens that were traded as marine aquarium fishes in Fortaleza, Ceara, Brazil, making this species 6.31% of all of the fishes reported being traded during these years (Monteiro-Neto et al. 2003).  The numbers of live Hippocampus erectus that were traded internationally and recorded in the CITES trade database are 160 from captivity, 59,156 - 62,114 from the wild, and 13,650 from unknown origins (Koldewey and Martin-Smith 2010).  85 specimens of H. erectus were collected for the live trades as well as the dried trades on the Atlantic coast of Latin America. Dried seahorses were usually sold unadorned or as key chains. Occasionally some of them were sold as jewellery, shell crafts with shells and sea stars, or as 'dragons' with wings and eyes attached. These dried seahorses were sometimes ground and consumed in a drink as folk medicine to treat asthma. Chinese populations in Panama and Peru sold seahorses commercially as medicine, for use as TCM. The live seahorses were traded as aquarium fishes. Also, in some countries, including Honduras and Costa Rica, they had in situ value because dive masters would take tourists to particular sites where these seahorses were located. It is believed that most live trades occur almost entirely on the black market, thus meaning that no records have been kept of the fishery or trade (Baum and Vincent 2005). A study conducted to see how icthyofauna are used in traditional medicine in Brazil reports several uses of this species. The  entirety of each specimen is used for therapies including athsma, alcoholism, thromboses, bronchitis, impotence, osteoporosis, heart disease, cancer, and rheumatism (El Deir et al. 2012).
The CITES Trade Database (CITES 2016) reports that on the order of  hundreds of animals per year are traded internationally for use in aquariums.

Threats [top]

Major Threat(s): Hippocampus erectus is threatened by being caught as bycatch in shrimp trawl fisheries and by being targeted for the aquarium trade. The species is traded dried as traditional medicine, curios, and live for aquariums (Vincent et al. 2011). This is a popular aquarium fish in North America. In Florida alone, thousands of H. erectus are collected each year for the aquarium trade (P. LaFrance unpublished data 2003). Hippocampus erectus is Brazil’s 6th most important marine ornamental export (Monteiro-Neto et al. 2000). In addition to being sold as traditional medicines, H. erectus are sold as curios in Mexico along the Caribbean coast (J. Baum unpublished data). Hippocampus erectus are often brought up as bycatch by shrimp trawling operations in Florida (Baum et al. 2003), and in Mexico seahorse population declines are attributed to indirect harvesting by the shrimp trawl fishery (J. Baum unpublished data). In Central America H. erectus are brought up in the shrimp trawls in Belize, Honduras, and Nicaragua, and are exported as TCM, or sold on both coasts as curios (Baum and Vincent 2005). Similarly in South America H. erectus are among the bycatch of shrimp trawls in Mar del Plata, Argentina (L. Magnasco in litt. to A. Vincent 23 May 1999), and in Brazil (I. Rosa and J. Baum unpublished data).

The preferred habitats of H. erectus (seagrasses, corals and mangroves) is also declining due to coastal development, pollution, destructive fishing practices such as trawling, and increased sedimentation (Carpenter et al. 2008, Polidoro et al. 2010, Short et al. 2011, Jackson et al. 2014). For example, in NE Brazil the development of shrimp farms has destroyed much of the coastal mangrove habitats where seahorses live (J. Gomezjuardo in litt. to A. Vincent Sept. 1999).

Conservation Actions [top]

Conservation Actions: The entire genus Hippocampus was listed in Appendix II of CITES in November 2002, with the listing being implemented in 2004 (Vincent et al. 2013, Foster et al. 2014). Full monitoring of the trade is underway in the United States, however this is dependent on traders’ declarations. Seahorses are listed under Title 68 (Rules of the Fish and Wildlife Conservation Commission) of the Florida Administrative Codes. The targeted fishery for the aquarium trade in Florida is monitored and regulations are in place, such as a limitation on the number of commercial harvesters, however the non-selective exploitation is not monitored in any state. Between the years of 1986 and 1998, the Coral Cay Conservation reported that Hippocampus erectus had a rare abundance in 7 proposed or established Marine Protected Areas where it was recorded: Turneffe Atoll, South Water Cay Marine Reserve, Sapodilla Cays, Snake Cays, and other unspecified areas (Harborne 2000). H. erectus has been frequently captured as bycatch by shrimp bait fishermen and it has been proposed to introduce seasonal and area closures (Baum et al. 2003).

Citation: Pollom, R. 2017. Hippocampus erectus. The IUCN Red List of Threatened Species 2017: e.T10066A20191442. . Downloaded on 17 December 2017.
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