Syngnathus acus 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Actinopterygii Syngnathiformes Syngnathidae

Scientific Name: Syngnathus acus Linnaeus, 1758
Regional Assessments:
Common Name(s):
English Longsnout Pipefish, Common Pipefish, Greater Pipefish, Great Pipefish
French Aiguille de Mer, Syngnathe Aiguille
Spanish Aguja de Mar
Sygnathus acus (Linnaeus, 1758)
Syngnathus alternans Günther, 1870
Syngnathus brachyrhynchus Kaup, 1856
Syngnathus delalandi Kaup, 1856
Syngnathus rubescens Risso, 1810
Syngnathus temminckii Kaup, 1856
Taxonomic Source(s): Linnaeus, C. 1758. Systema naturae per regna tria naturae, secundum classes, ordinus, genera, species, cum characteribus, differentiis, synonymis, locis. Tomus I. Editio decima, reformata. Impensis Direct, Laurentii Salvii, Holmiae.

Assessment Information [top]

Red List Category & Criteria: Least Concern ver 3.1
Year Published: 2015
Date Assessed: 2013-05-07
Assessor(s): Smith-Vaniz, W.F.
Reviewer(s): Strongin, K., Polidoro, B. & Carpenter, K.E.
Syngnathus acus is widely distributed from Norway throughout the Mediterranean and south to Gambia. There is a broad disjunct distribution from Gambia to Angola with occurrence resuming in northern Namibia to Zululand (Indian Ocean). This species inhabits algal and seagrass beds and may be affected by habitat degradation. Additional information about the population trend and life history of this species is not available. It is therefore listed as Least Concern given its wide distribution and lack of known major threats. Monitoring of its eelgrass and algal habitats is recommended.

Geographic Range [top]

Range Description:Syngnathus acus is extant in waters along the Eastern Atlantic from the Baltic Sea near the Faeroe Islands, Norway and down through the British Isles to Western Sahara and from Senegal and Gambia. It is also found from Namibia to Cape of Good Hope and northward to the coast of Zululand in the western Indian Ocean (Dawson 1986). It is also found throughout the Mediterranean and Black seas. This species has also been identified from the Azores.
Despite literature records, occurrence in the Indo-Pacific outside South African waters lacks conclusive evidence.

This species occurs at depths from 10-110 m (Dawson 1986).
Countries occurrence:
Albania; Algeria; Belgium; Bosnia and Herzegovina; Bulgaria; Croatia; Cyprus; Denmark; Egypt (Egypt (African part)); Faroe Islands; France (Corsica, France (mainland)); Georgia; Germany; Gibraltar; Greece (East Aegean Is., Greece (mainland), Kriti); Guernsey; Ireland; Isle of Man; Israel; Italy (Italy (mainland), Sardegna, Sicilia); Jersey; Lebanon; Libya; Malta; Monaco; Montenegro; Morocco; Namibia (Caprivi Strip, Namibia (main part)); Netherlands; Norway; Portugal (Azores, Portugal (mainland)); Romania; Slovenia; South Africa (Eastern Cape Province, KwaZulu-Natal, Northern Cape Province, Western Cape); Spain (Baleares, Spain (mainland)); Sweden; Syrian Arab Republic; Tunisia; Turkey; United Kingdom (Great Britain, Northern Ireland); Western Sahara
FAO Marine Fishing Areas:
Atlantic – southeast; Atlantic – northeast; Atlantic – eastern central; Indian Ocean – western; Mediterranean and Black Sea
Additional data:
Lower depth limit (metres):110
Upper depth limit (metres):10
Range Map:Click here to open the map viewer and explore range.

Population [top]


There have not been any dedicated population estimates for Syngnathus acus to date. Population status and trend are unknown. 

There are over 3,400 records on the Global Biodiversity Information Facility (GBIF 2014), indicating that this species is relatively common. Two hundred and one museum records for Syngnathus acus with quite a few records of 15 or more individuals may suggest local abundance in some areas (Fishnet2 2014).
Current Population Trend:Unknown
Additional data:

Habitat and Ecology [top]

Habitat and Ecology:Syngnathus acus is a demersal species that inhabits coastal and estuarine areas with sea grass beds, such as Zostera species. It uses sea grasses as breeding and feeding grounds and as shelter from prey. This species feeds on small invertebrates and fish larvae including harpacticoid copepods, amphipods, cypris larvae and decapod crustaceans (Taçkavak et al. 2013). Gurkan et al. (2009) speculate that the large distribution of average sizes at maturity is due to water temperatures. Subpopulations inhabiting colder seas tend to reach sexual maturity later, and thus reach a longer length in comparison to species found in warmer temperatures.

Syngnathus acus
is polygamous, so males are able to accept eggs from multiple females, and carry them for the incubation period in their brood pouches (Gurkan et al. 2009). After several weeks, the males give birth to fully formed juveniles measuring an average of 2.6 cm. This species has been shown to display filial cannibalism in captivity, as newborns are often preyed upon by adult pipefish, their own parents included (Silva et al. 2006). Sexual dimorphism in body size is absent in this species (Gurkan et al. 2009).

In a study by Silva et al. (2006) on the early life history behaviour of S. acus, it was observed that newborn juveniles immediately adopted a benthic strategy, and kept close, continual contact with the strata. This behaviour was thought to limit the species ability to disperse and colonize new areas in comparison to species with a pelagic early life stage. This may result in an increased vulnerability to habitat fragmentation and degradation.


Continuing decline in area, extent and/or quality of habitat:Yes

Use and Trade [top]

Use and Trade:

The utilization of this species in the Eastern Central Atlantic is unknown (Smith-Vaniz pers. comm. 2013). Some pipefish species are caught as bycatch and subsequently used as a substitute for Hippocampus species in traditional Chinese medicine (Vincent et al. 2011). Pipefishes are considered to be less effective and are cheaper in price (West 2012).

Threats [top]

Major Threat(s): Habitat degradation and disturbance through direct anthropogenic activities such as coastal developments and the effect of fishing gear (e.g. trawls and dredges) may pose a threat to Syngnathus acus (Vincent et al.  2011, 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 this species' geographic range, and like other small coastal fish, is also threatened by pollution from shore side run-off and ships (Islam and Tanaka 2004). Seagrass habitats are declining globally and also in Europe (Airoldi and Beck 2007, Short et al. 2011). It is not clear to what extent seagrass loss is affecting wild subpopulations of Syngnathus acus. Closer monitoring of seagrass habitat is needed to determine regional-scale declines over shorter time frames.

Conservation Actions [top]

Conservation Actions: There are no species-specific conservation efforts in place for Syngnathus acus. However, its distribution overlaps with marine reserves in parts of its range (World Database on Protected Areas 2010).

Citation: Smith-Vaniz, W.F. 2015. Syngnathus acus. The IUCN Red List of Threatened Species 2015: e.T198765A44933898. . Downloaded on 21 September 2018.
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