Sprat is the common name applied to a group of

forage fish Forage fish, also called prey fish or bait fish, are small pelagic fish which are preyed on by larger predators for food. Predators include other larger fish, seabirds and marine mammals. Typical ocean forage fish feed near the base of the f ...

belonging to the genus '' Sprattus'' in the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Clupeidae Clupeidae is a family of ray-finned fishes, comprising, for instance, the herrings, shads, sardines, hilsa, and menhadens. The clupeoids include many of the most important food fishes in the world, and are also commonly caught for producti ...

. The term also is applied to a number of other small sprat-like forage fish ('' Clupeoides'', '' Clupeonella'', '' Corica'', '' Ehirava'', ''

Hyperlophus ''Hyperlophus'' is a genus of sprat belonging to the herring family Clupeidae Clupeidae is a family of ray-finned fishes, comprising, for instance, the herrings, shads, sardines, hilsa, and menhadens. The clupeoids include many of the most im ...

'', '' Microthrissa'', '' Nannothrissa'', '' Platanichthys'', '' Ramnogaster'', '' Rhinosardinia'', and '' Stolothrissa''). Like most forage fishes, sprats are highly active, small,

oily fish Oily fish are fish species with oil (fats) in soft tissues and in the coelomic cavity around the gut. Their fillets may contain up to 30% oil, although this figure varies both within and between species. Examples of oily fish include sma ...

. They travel in large schools with other fish and swim continuously throughout the day.Meskendahl, L., J.-P. Herrmann, and A. Temming. "Effects of Temperature and Body Mass on Metabolic Rates of Sprat, Sprattus Sprattus L." ''Marine Biology'' 157.9 (2010): 1917–1927. Academic Search Premier. Web. 26 November 2011. p. 192

/ref> They are recognized for their nutritional value, as they contain high levels of polyunsaturated fats, considered beneficial to the human diet. They are eaten in many places around the world. Sprats are sometimes passed off as other fish; products sold as having been prepared from anchovies (since the 19th century) and others sold as sardines sometimes are prepared from sprats, as the authentic ones once were less accessible. They are known for their smooth flavour and are easy to mistake for baby sardines.

Species

True sprats

True sprats belong to the genus '' Sprattus'' in the family

. The five species are: * Type species

Other sprats

The term also is commonly applied to a number of other small sprat-like forage fish that share characteristics of the true sprat. Apart from the true sprats,

FishBase FishBase is a global species database of fish species (specifically finfish). It is the largest and most extensively accessed online database on adult finfish on the web.

lists another 48 species whose common names ends with "sprat". Some examples are:

Characteristics

The average length of time from fertilization to hatching is about 15 days, with environmental factors playing a major role in the size and overall success of the sprat.Nissling, Anders. "Effects of Temperature on Egg And Larval Survival of Cod (Gadus Morhua) And Sprat (Sprattus Sprattus) In The Baltic Sea – Implications For Stock Development." ''Hydrobiologia'' 514.1-3 (2004): 115-123. Academic Search Premier. Web. 24 November 2011. p. 12

/ref> The development of young larval sprat and reproductive success of the sprat have been largely influenced by environmental factors. Some of these factors affecting the sprat can be seen in the Baltic Sea, where

specific gravity Relative density, or specific gravity, is the ratio of the density (mass of a unit volume) of a substance to the density of a given reference material. Specific gravity for liquids is nearly always measured with respect to water at its dens ...

, water temperature, depth, and other such factors play a role in their success. Over the last two decades, the number of sprat has fluctuated, due primarily to availability of

zooplankton Zooplankton are the animal component of the planktonic community ("zoo" comes from the Greek word for ''animal''). Plankton are aquatic organisms that are unable to swim effectively against currents, and consequently drift or are carried along by ...

, a common food source, and also from overall changes in Clupeidae total abundance. Although the overall survival rates of the sprat decreased in the late 1980s and early 1990s, an increase has occurred in the last two decades. Recent studies suggesting a progression in the reproductive success of the sprat acknowledge that a significant increase in spawning stock biomass occurred. One of the main concerns for reproductive success for the sprat include exceedingly cold winters, as cold temperatures, especially in the Baltic Sea, have been known to affect the development of sprat eggs and larvae. The metabolic rate of the sprat is highly influenced by environmental factors such as water temperature. Several related fish, such as the

Atlantic herring Atlantic herring (''Clupea harengus'') is a herring in the family Clupeidae. It is one of the most abundant fish species in the world. Atlantic herrings can be found on both sides of the Atlantic Ocean, congregating in large schools. They can ...

(''C. harengus''), have much lower metabolic rates than that of the sprat. Some of the difference may be due to size differences among the related species, but the most important reason for high levels of metabolism for the sprat is their exceedingly high level of activity throughout the day.

Distribution

Fish of the different species of sprat are found in various parts of the world including New Zealand, Australia, and parts of Europe. By far, the most highly studied location where sprat, most commonly ''Sprattus sprattus'', reside is the

Baltic Sea The Baltic Sea is an arm of the Atlantic Ocean that is enclosed by Denmark, Estonia, Finland, Germany, Latvia, Lithuania, Poland, Russia, Sweden and the North and Central European Plain. The sea stretches from 53°N to 66°N latitude and from ...

in Northern Europe. The Baltic Sea provides the sprat with a highly diverse environment, with spatial and temporal potential allowing for successful reproduction.Friedrich W. Köster, et al. "Developing Baltic Cod Recruitment Models. I. Resolving Spatial And Temporal Dynamics of Spawning Stock And Recruitment For Cod, Herring, And Sprat." ''Canadian Journal of Fisheries & Aquatic Sciences'' 58.8 (2001): 1516. Academic Search Premier. Web. 21 November 2011. p. 1516

/ref> One of the most well-known locations in the Baltic Sea where they forage for their food is the

Bornholm Bornholm () is a Danish island in the Baltic Sea, to the east of the rest of Denmark, south of Sweden, northeast of Germany and north of Poland. Strategically located, Bornholm has been fought over for centuries. It has usually been ruled by ...

Basin, in the southern portion of the Baltic Sea.Casini, Michele, Cardinale, Massimiliano, and Arrheni, Fredrik. "Feeding preferences of herring (Clupea harengus) and sprat (Sprattus sprattus) in the southern Baltic Sea". ''ICES Journal of Marine Science'', 61 (2004): 1267-1277. Science Direct. Web. 22 November 2011. p. 1268

/ref> Although the Baltic Sea has undergone several ecological changes during the last two decades, the sprat has dramatically increased in population.Casini, Michele, Massimiliano Cardinale, and Joakim Hjelm. "Inter-Annual Variation in Herring, Clupea Harengus, And Sprat, Sprattus Sprattus, Condition in the Central Baltic Sea: What Gives The Tune?." ''Oikos'' 112.3 (2006): 638-650. Academic Search Premier. Web. 22 November 2011. p. 638

/ref> One of the environmental changes that has occurred in the Baltic Sea since the 1980s includes a decrease in water salinity, due to a lack of inflow from the North Sea that contains high saline and oxygen content.

Ecology

Scramble^^ A Gannet begins its take off run

In the Baltic Sea, cod,

herring Herring are forage fish, mostly belonging to the family of Clupeidae. Herring often move in large schools around fishing banks and near the coast, found particularly in shallow, temperate waters of the North Pacific and North Atlantic Ocean ...

, and sprat are considered the most important species. Cod is the top predator, while the herring and sprat primarily are recognized as prey. This has been proven by many studies that analyze the stomach contents of such fish, often finding contents that immediately signify predation among the species. Although cod primarily feed on adult sprat, sprat tend to feed on cod before the cod have been fully developed. The sprat tends to prey on the cod eggs and larvae. Furthermore, sprat and herring are considered highly competitive for the same resources that are available to them. This is most present in the vertical migration of the two species in the Baltic Sea, where they compete for the limited zooplankton that is available and necessary for their survival. Sprats are highly selective in their diet and are strict zooplanktivores that do not change their diet as their size increases, like some herring, but include only zooplankton in their diet. They eat various species of zooplankton in accordance to changes in the environment, as temperature and other such factors affect the availability of their food. During autumn, sprats tend to have a diet high in '' Temora longicornis'' and '' Bosmina maritime''. During the winter, their diet includes ''Pesudocalanus elongates''. ''Pseudocalanus'' is genus of the order

Calanoida Calanoida is an order of copepods, a group of arthropods commonly found as zooplankton. The order includes around 46 families with about 1800 species of both marine and freshwater copepods between them. Description Calanoids can be distinguis ...

and subclass Copepoda that is important to the predation and diet of fish in the Baltic Sea. In both autumn and winter, a tendency exists for sprats to avoid eating ''

Acartia ''Acartia'' is a genus of marine calanoid copepods. They are epipelagic, estuarine, zooplanktonic found throughout the oceans of the world, primarily in temperate regions. Classification This genus contains the majority of species in the fa ...

'' spp., because they tend to be very small in size and have a high escape response to predators such as the herring and sprat. Although ''Acartia'' spp. may be present in large numbers, they also tend to dwell more toward the surface of the water, whereas the sprats, especially during the day, tend to dwell in deeper waters.

Fisheries

File:Time series for global capture of all sprats 2.png, Global commercial capture of sprats in million tonnes 1950–2010Based on data sourced from the relevan
FAO Species Fact Sheets
/ref> File:Global total production sprats.png, The total capture of sprats in 2010 reported by the FAO was 667,000 tonnes.

As food

In Northern Europe, European sprats are commonly smoked and preserved in oil, which retains a strong, smoky flavor. Sprat, if smoked, is considered to be one of the foods highest in

purine Purine is a heterocyclic aromatic organic compound that consists of two rings ( pyrimidine and imidazole) fused together. It is water-soluble. Purine also gives its name to the wider class of molecules, purines, which include substituted purines ...

content.Various food types and their purine content http://www.acumedico.com/purine.htm People who suffer from

gout Gout ( ) is a form of inflammatory arthritis characterized by recurrent attacks of a red, tender, hot and swollen joint, caused by deposition of monosodium urate monohydrate crystals. Pain typically comes on rapidly, reaching maximal intens ...

or high uric acid in the blood should avoid eating such foods. Most importantly, sprats contain long-chain

polyunsaturated fatty acids Polyunsaturated fatty acids (PUFAs) are fatty acids that contain more than one double bond in their backbone. This class includes many important compounds, such as essential fatty acids and those that give drying oils their characteristic pr ...

, including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). They are present in amounts comparable to Atlantic salmon, and up to seven times higher in EPA and DHA than common fresh fillets of gilt-head bream. The sprats contain about 1.43 g/100 g of these polyunsaturated fatty acids that have been found to help prevent mental, neural, and cardiovascular diseases.Galina S. Kalachova, et al. "Content of essential polyunsaturated fatty acids in three canned fish species." ''International Journal of Food Sciences & Nutrition'' 60.3 (2009): 224-230. Academic Search Premier. EBSCO. Web. 26 October 2011. p.224

/ref> File:Sprattus sprattus.jpg, ''Sprattus sprattus'', the European sprat File:Visserijmuseum048.jpg, Creel (basket), Creel with sprat, National Fishery Museum, Belgium File:Visserijmuseum047.jpg, Oven for smoking sprat, National Fishery Museum, Belgium