|Scientific Name:||Gasterosteus aculeatus|
|Species Authority:||Linnaeus, 1758|
|Taxonomic Notes:||Populations from the Atlantic and Black Sea basins have not yet been compared in detail. Preliminary observations suggest that they are probably distinct species.|
|Red List Category & Criteria:||Least Concern ver 3.1|
|Reviewer(s):||Smith, K. & Darwall, W.R.T.|
|Contributor(s):||Freyhof, J., Kottelat, M. & Lukey, J.R.|
|Facilitator/Compiler(s):||Hammerson, G.A. & Ormes, M.|
Gasterosteus aculeatus has been assessed as Least Concern. This species has an extremely broad native distribution, with a large number of subpopulations. This species is not known to be impacted by any major threat processes and is reported to be common to abundant throughout most of its distribution: Consequently the population is considered to be stable.
|Range Description:||The range of Gasterosteus aculeatus encompasses the coastal waters of Eurasia, Iceland, eastern Asia and Northern America. In North America, this fish ranges from Alaska to Baja California on the west coast, from Baffin Island and the west side of Hudson Bay to Chesapeake Bay, Virginia, along east coast, and it occurs also in inland areas (including Lake Ontario) along both coasts. Sometimes this species occurs in the open ocean. This species has been introduced and is established in certain areas of California, Massachusetts, and the Great Lakes (Lakes Huron, Michigan, Erie and Superior) (Fuller et al. 1999; Stephenson and Momot 2000). In Eurasia it is found along North Sea coasts of Scotland and Scandinavia; coasts of Iceland and White Sea; Atlantic coasts from Ireland northward; southeastern shore of Baltic Sea and its basin (Odra and Vistula drainages); shores of Black Sea and its northern basin (from Danube to Kuban drainages). Almost absent inland in Finland, except north of 68°N. There is a hybrid zone with G. gymnurus in the English Channel, southern North Sea, Baltic Sea and their basins. It has been introduced to northern Italy.|
Native:Algeria; Belarus; Belgium; Bosnia and Herzegovina; Canada; China; Croatia; Denmark; Estonia; Finland; France; Georgia; Germany; Greece; Greenland; Iceland; Ireland; Japan; Korea, Democratic People's Republic of; Korea, Republic of; Latvia; Lithuania; Mexico; Netherlands; Norway; Poland; Portugal; Romania; Russian Federation; Slovenia; Spain; Sweden; Switzerland; Turkey; Ukraine; United Kingdom; United States (Georgia)
Introduced:Austria; Czech Republic; Hungary; Iran, Islamic Republic of; Italy; Slovakia
|FAO Marine Fishing Areas:||
Atlantic – northwest; Mediterranean and Black Sea; Pacific – eastern central; Pacific – northeast
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||This is an abundant species.|
|Habitat and Ecology:||
This species is typically found in quiet weedy pools and backwaters. It is also found in the marginal vegetation of streams, over sand and mud bottom substrates. Marine populations are pelagic, and usually found inshore along the coast, in estuaries and coastal lagoons. In some lakes, two morphologically and ecologically distinct forms may occur, differing in habitat (one littoral, the other mainly limnetic). Eggs are deposited in freshwater in a nest of plant material made by the male on the bottom in shallow water. The female will typically lay a few hundred eggs and may lay eggs in several nests over a period of several days (Morrow 1980).
Anadromous, with numerous resident populations in brackish or pure freshwater, rarely in marine waters. Usually forages at sea until two years old, then moves to lower part of rivers in March-April to reproduce. Freshwater populations usually spawn for the first time at one year. In spawning season, males develop a bright orange to red belly and blue-green flank and eyes. They defend territories, in which in April-June they construct a nest on the bottom, in relatively shallow areas, very rarely attached to plants. They make a depression up to 14 × 10 cm to which they bring plant materials (especially filamentous algae), which are glued together with kidney secretions. Several females are individually led to the nest to spawn, then chased away. Males guard and fan eggs to provide them with oxygenated water. Spawning behaviour is very stereotyped. Eggs hatch in 7-8 days and juveniles are guarded for a few days after which male abandons the nest. Anadromous individuals usually die of exhaustion after spawning cycle while freshwater individuals are able to complete several cycles within one year or sometimes over several years. Juveniles move to sea (anadromous populations) or to deeper, larger water bodies (freshwater populations) in July-August where they form large feeding schools. Feeds on small aquatic invertebrates, especially insects and crustaceans.
|Major Threat(s):||No major widespread threats known. However, the species has been listed as threatened in some of its range states, for example it is listed as Endangered in Croatia.|
|Conservation Actions:||There are no species-specific conservation measures in place, or needed, for Gasterosteus aculeatus.|
|Citation:||NatureServe 2015. Gasterosteus aculeatus. The IUCN Red List of Threatened Species. Version 2015.2. <www.iucnredlist.org>. Downloaded on 02 September 2015.|
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