Hippocampus guttulatus 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Actinopterygii Syngnathiformes Syngnathidae

Scientific Name: Hippocampus guttulatus Cuvier, 1829
Regional Assessments:
Common Name(s):
English Long-snouted Seahorse, Seahorse
French Cheval Marin, Hippocampe Moucheté
Spanish Caballito de Mar
Hippocampus filamentosus Duméril, 187O
Hippocampus hippocampus ssp. microcoronatus Slastenenko, 1938
Hippocampus hippocampus ssp. microstephanus Slastenenko, 1937
Hippocampus longirostris Schinz, 1822
Hippocampus ramulosus Leach in Leach & Nodder, 1814
Taxonomic Source(s): Cuvier, G. 1829. Le Règne Animal, distribué d'après son organisation, pour servir de base à l'histoire naturelle des animaux et d'introduction à l'anatomie comparée. Edition 2. Volume 2.
Taxonomic Notes: All Black Sea specimens examined thus far have been genetically identified as Hippocampus guttulatus, with no evidence of a separate species (Woodall 2009). This supersedes previous suggestions that a new and different species or subspecies inhabits the Black Sea.

Assessment Information [top]

Red List Category & Criteria: Data Deficient ver 3.1
Year Published: 2017
Date Assessed: 2016-12-05
Assessor(s): Pollom, R.
Reviewer(s): Ralph, G.
Contributor(s): Woodall, L.
Hippocampus guttulatus is a coastal marine seahorse that inhabits macroalgae, seagrass, sand and mud, sessile invertebrates, reefs and lagoons in Europe and the Mediterranean. Populations appear to fluctuate widely, and trends in abundance indicate both declines and increases in different areas. Habitat loss and degradation have contributed to declines. The species is threatened by habitat loss and degradation due to pollution and destructive fishing practices, and is often caught as bycatch. Further research is needed in order to estimate population size and trends in abundance across this species' range, and population and habitat monitoring are needed. Therefore H. guttulatus is listed as Data Deficient.
Previously published Red List assessments:

Geographic Range [top]

Range Description:Hippocampus guttulatus is primarily a species of European waters. The species is present along the Atlantic coast from the UK, Ireland and Netherlands to the Mediterranean Sea. Distribution continues throughout the Mediterranean Sea and Black Seas (Woodall et al. 2015, Lourie et al. 2016).
Countries occurrence:
Bulgaria; Croatia; Cyprus; France; Georgia; Greece; Ireland; Israel; Italy; Malta; Monaco; Netherlands; Portugal; Romania; Russian Federation; Spain; Syrian Arab Republic; Tunisia; Turkey; Ukraine; United Kingdom
FAO Marine Fishing Areas:
Atlantic – eastern central; Atlantic – northeast; Mediterranean and Black Sea
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):30
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:There is no global estimate of H. guttulatus population size or trends in abundance. However there are several locations where datasets are available regarding population size and trends.

In the Ria Formosa lagoon (southern Portugal), the H. guttulatus population decreased by 94% from 2002 to 2007 (from 0.073 indivduals/m² to 0.004 individuals/m² - Curtis and Vincent 2005, Caldwell and Vincent 2012). More recent surveys at this location revealed that the population size is possibly increasing again to 0.039-0.140 indivduals/m² (Correia et al. 2014, 2015).  H. guttulatus has been shown to utilise complex habitats (Curtis and Vincent 2005, Gristina et al. 2015), with populations apparently fluctuating according to the availability of holdfasts (Correia et al. 2015).

In the Thau Lagoon (Southern France), H. guttulatus populations have fluctuated each year, however no long term trend has been observed (2005–2009) (Louisy 2011). In the Arcachon Basin (Western France), interviews suggest that the population distribution is very patchy, but to date no trend has been established due to lack of consistent data collection (2005–2011) (Grima 2011).

In the Gulf of Lion, it is reported that this species was easily caught in this area up until the 1980’s. Since that time, it has become rarer and the populations appear to have declined significantly (anecdotal evidence and field experience) (J.P. Quignard pers. comm. 2007). Mayol et al. (2000) state that there have been population declines in the Balearic Islands. Goffredo et al. (2004) remarked that among the 3,061 seahorse specimens caught around Italy, 68% were this species.

In the Mar Piccolo di Taranto, southeastern Italy, there was a mean abundance of 0.018 individuals/m² (SE +/-0.003) in the summer of 2012 (ranging from a maximum of 0.035 individuals/m² (SE +/-0.007) to a minimum of 0.008 individuals/m² (SE +/-0.002)) (Gristina et al. 2015).

Anecdotal evidence is available in other locations, but without exhaustive surveys and systematic data collection. In Mar Menor, (Southern Spain), Voiotias, (Greece) and Varna, (Bulgaria) the population size of H. guttulatus fluctuates greatly each year (2005–2011) (anecdotal evidence compiled by L. Woodall). In other coastal sites populations have both decreased (Badalona, Spain- J. Ortiz, SASBA,  in. litt. 2012; Malaga, Spain- P. Cabrera, in. litt. 2012; Galicia, Spain- S. Valladares, in. litt. 2012) and increased (La Herradura, Spain- P. Cabrera, in. litt. 2012). It is therefore difficult to generalise on population trends for this species throughout its range. Systematic and range-wide monitoring need to be implemented on an ongoing basis in order to determine the true population size and trends in abundance for this species.
Current Population Trend:Unknown
Additional data:
Extreme fluctuations:Yes
Continuing decline in subpopulations:Unknown
Extreme fluctuations in subpopulations:UnknownAll individuals in one subpopulation:No

Habitat and Ecology [top]

Habitat and Ecology:Hippocampus guttulatus are mostly found inhabiting small home ranges in shallow coastal waters, lagoon systems and estuaries (0.5–15 m; Curtis and Vincent 2005,Curtis and Vincent 2006, Garrick-Maidment and Jones 2004, Woodall 2009) but there may be seasonal migration to deeper waters (30 m+) (Boisseau 1967, Garrick-Maidment 2007, Garrick-Maidment and Jones 2004). Adult H. guttulatus use varied habitats, of all sediment types, macroalgae and seagrass and in addition are often observed on artificial structures using them as holdfasts (Garrick-Maidment and Jones 2004, Curtis and Vincent 2005, Franco et al. 2006, Woodall 2009, Louisy 2010, Gristina et al. 2015). 

In the Ria Formosa adult H. guttulatus are associated with complex habitats, including Zostera marina, Ulva spp., Codium spp. and artificial structures (Curtis and Vincent 2005, Correia et al. 2015). However this species is seen in different habitats such as rocky areas, sand/silt ripples, sessile invertebrates and sponges in other locations such as the U.K, Bulgaria, Spain, France and Greece (Garrick-Maidment and Jones 2004, Woodall 2009, Louisy 2010).

As an ambush predator, H. guttulatus has a wide dietary range that mainly comprises Amphipoda, Anmura, Decopoda and Mysidaceae (Kitsos et al. 2008, Gurkan et al. 2011) and thus is associated with highly productive habitats. Valladares et al. (2016) used stable isotopes to study diet, with Caprellidea being the primary source, followed by Gammaridea and Caridea. Mysidae and Annelida were consumed in lower numbers.  Sex differences in diet were found - Caprellidea was the most important prey for females; Gammaridea was the dominant prey for males.

Hippocampus guttulatus are seasonal breeders (approx. March to October) with a temperature limited mating and gestation period of around 21 days (Boisseau 1967, Curtis 2007). Like all other seahorses, they are ovoviviparous, and the males brood the young in a pouch prior to giving live birth (Foster and Vincent 2004). Predicted annual fecundity for this species is about 900 young and is correlated with fish size, but the size of the male brood pouch is inferred to be a limiting factor for both sexes (Curtis 2007).

In the Ria Formosa, newborn H. guttulatus are about 12 mm and are seen in adult habitat at 96 mm. Males are mature at 109 mm, reproduce at 125 mm and live for approximately 5 years (Curtis and Vincent 2006). Juvenile H. guttulatus (less than 96 mm) are rarely observed during surveys (Curtis and Vincent 2006, Woodall 2009, Louisy 2010). They spend the first weeks of life as plankton, but nothing more is known about them until recruitment at 96 mm (Boisseau 1967). Juvenile development ex-situ is determined by water temperature, food availability and condition at birth (J. Palma pers. comm. 2012).

Hippocampus guttulatus adults have low dispersal and limited migration (Caldwell and Vincent 2012, 2013). This reduces their ability to colonise new areas, recolonise old ones, and in addition reduces their ability to move when habitat becomes unfavourable. H. guttulatus, consistent with other seahorses, has a genetically monogamous mating system, at least within a breeding season (Woodall et al. 2011), and this may reduce their reproductive potential if their partner is removed from the population (e.g. caught). However H. guttulatus matures at an early age, has rapid growth rates, and a short generation time, traits which suggest that it may recover rapidly when direct (e.g., exploitation) and indirect (e.g., by-catch and habitat damage) effects of disturbance cease, but it may then be vulnerable to extended periods of poor recruitment (Curtis and Vincent 2006).
Continuing decline in area, extent and/or quality of habitat:Yes
Generation Length (years):2
Movement patterns:Not a Migrant

Use and Trade [top]

Use and Trade: No specific targeted fisheries are known in Europe for H. guttulatus. There may be exploited populations in Africa but the extent of the species' range in this region is unconfirmed. International trade is required to be documented as sustainable, as H. guttulatus is listed on CITES Appendix II. Recent CITES-reported trade is minimal and on the order of tens of animals per year (CITES 2016). Seahorse species are, however, often misidentified (L. Woodall pers. obs.).

Individuals retained in bycatch are sometimes sold as curiosities, good-luck charms and for use in traditional medicines (Portugal and France; L. Woodall pers. obs.; Vincent et al. 2011). This species is also collected occasionally under permits for displays in local public aquariums (Portugal and France; L. Woodall pers. obs.). It is not clear how much offtake is occurring and the overall effect of bycatch on this species is unknown.

Threats [top]

Major Threat(s): The major continuing threat to H. guttulatus is habitat degradation and disturbance through direct anthropogenic activities such as coastal developments and the effect of fishing gear (e.g., trawls and dredges) (Caldwell and Vincent 2012). As it is a shallow coastal species it is extremely susceptible to anthropogenic activities. Habitat degradation through climate change continues across H. guttulatus' range. The species is also threatened by pollution and habitat degradation from shore side run-off (Islam and Tanaka 2004).

Seahorses are caught both intentionally and incidentally in Portugal, and sold for curiosities or into the live aquarium fish trade (J. Curtis, in litt. 2012). They are also caught incidentally in Italy, France, Spain and Croatia (J. Curtis 2012). The volume of this trade is unknown, but without appropriate management this trade might represent a threat to the species.

Conservation Actions [top]

Conservation Actions: The entire genus Hippocampus is listed in Appendix II of CITES. Hippocampus guttulatus has been listed under OSPAR, European CITES, (Curd 2009) the Bern Convention and Barcelona Convention (Abdul Malak et al. 2011) .

Regionally, it is listed as Near Threatened in the Mediterranean and Endangered in Croatia (Jardas et al. 2007). In the Black Sea region, it is listed as Endangered by Turkey, Vulnerable in Georgia and the Ukraine, and Least Concern in Romania (Yankova 2012). The species is listed in National Red Data Books in Bulgaria, France, Portugal and Slovenia (Yankova 2012). H. guttulatus is protected by the UK Wildlife and Countryside Act of 2008 (DEFRA 2008) and is a UK Biodiversity Action Plan priority species (JNCC 2010).

Further research on this species' biology, ecology, habitat, abundance and distribution is needed. Long-term monitoring is required for this species across its geographic range focusing on population trends, harvest level trend and habitat trends.

Citation: Pollom, R. 2017. Hippocampus guttulatus. The IUCN Red List of Threatened Species 2017: e.T41006A67617766. . Downloaded on 23 September 2018.
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