Aquaculture of brine shrimp
Encyclopedia
Brine shrimp
have the ability to produce dormant eggs, known as cyst
s. This has led to the extensive use of brine shrimp in aquaculture
. The cysts may be stored for long periods and hatched on demand to provide a convenient form of live feed for larval fish and crustaceans
. Nauplii of the brine shrimp constitute the most widely used food item, and over 2000 tonnes of dry brine shrimp cysts are marketed worldwide annually. In addition, the resilience of brine shrimp makes them ideal animals for running biological toxicity assays and is now one of the standard organisms for testing the toxicity
of chemicals.
Fish farm owners search for a cost-effective, easy to use, and available food that is preferred by the fish. From cysts, brine shrimp nauplii can readily to be used to feed to fish and crustacean larvae just after one-day incubation
. Instar
I (the nauplii that just hatched and with large yolk reserves in their body) and instar II nauplii (the nauplii after first moult and with functional digestive tracts) are more wildly used in aquaculture, for the reasons they are easy for operation, nutrients rich, and of small size which makes them suitable for feeding fish and crustacean larvae live or after drying.
In their first stage of development, brine shrimp nauplii do not feed but consume their own energy reserves stored in the cyst. Wild brine shrimp eat microscopic planktonic
algae
. Cultured brine shrimp can also be fed particulate foods including yeast
, wheat
flour
, soybean
powder
or egg yolk
.
which has a brown colour. These eggs, also known as cysts, are metabolically
inactive and can remain in total stasis for two years while in dry oxygen-free conditions, even at temperatures below freezing. This characteristic is called cryptobiosis
, meaning "hidden life". While in cryptobiosis, brine shrimp eggs can survive temperatures of liquid air
(-190 C) and a small percentage can survive above boiling temperature (105 °C or 221 °F) for up to two hours.
Once placed in briny (salt) water (>5‰), the eggs hatch within a few hours. The nauplii, or larvae, are less than 0.4 mm in length when they first hatch. Brine shrimp have a biological life cycle
of one year.
formulation is yet available to completely substitute for brine shrimp, feeding live prey to young fish and crustacean larvae still remains essential in commercial hatchery
operation. The nutritional properties of newly hatched brine shrimp are high in lipid
s and unsaturated fatty acids
(but low in calcium
). Dried brine shrimp nauplii contain 37%–71% protein, 12%–30% lipid, 11%–23% carbohydrate, and 4%–21% ash.
The fatty acid compositions of the nauplii are highly environmentally determined. Also the nutritional quality of commercially available brine shrimp strains being relatively poor in eicosapentaenoic acid
(EPA, 20:5n-3), and especially docosahexaenoic acid
(DHA, 22:6n-3). Since these components are critical for the larvae development, it is common practice to feed this live prey with emulsions of marine oils
that are rich in the EPA and DHA, which is referred as enrichment
processes.
in the USA
has been the major supplier of brine shrimp cysts to the world aquaculture industry and the subject of numerous speculations regarding its capacity to sustain a growing aquaculture industry. However, due to the unpredictable fluctuation of the cyst yield from Great Salt Lake, there are other sites for cyst production, such as lake Urmia
in Iran, Aibi Lake in China
, Bolshoye Yarovoye
in Siberia
, Kara Bogaz Gol in Turkmenistan
, and several lakes in Kazakhstan
.
Although hatchery process of brine shrimp are relative simple and easy to operate, a series of factors need to be controlled and monitored to make optimal use of the cysts. The critical factors are light, temperature, salinity
, oxygen level, pH
and cyst density, which vary between different brine shrimp strains. Hatching quality can be described by hatching efficiency (number of nauplii per gram of cysts), hatching percentage or hatching synchrony
(time between first and last hatching cysts).
There are six stages in the hatching and development of brine shrimp industrial hatchery.
After hatching, and prior to feeding them to the fish or crustacean larvae, brine shrimp nauplii should be separated from the hatching wastes. After switching off the aeration
in the hatching tank, cyst shells will float and nauplii will concentrate at the bottom of the tank. The nauplii are further concentrated in a concentrator
rinse and separated from the cysts.
The enrichment process, if needed, generally occurs after the nauplii develop a digestive tract
. The three main enrichment approaches are listed below.
Brine shrimp
Artemia is a genus of aquatic crustaceans known as brine shrimp. Artemia, the only genus in the family Artemiidae, has changed little externally since the Triassic period...
have the ability to produce dormant eggs, known as cyst
Cyst
A cyst is a closed sac, having a distinct membrane and division on the nearby tissue. It may contain air, fluids, or semi-solid material. A collection of pus is called an abscess, not a cyst. Once formed, a cyst could go away on its own or may have to be removed through surgery.- Locations :* Acne...
s. This has led to the extensive use of brine shrimp in aquaculture
Aquaculture
Aquaculture, also known as aquafarming, is the farming of aquatic organisms such as fish, crustaceans, molluscs and aquatic plants. Aquaculture involves cultivating freshwater and saltwater populations under controlled conditions, and can be contrasted with commercial fishing, which is the...
. The cysts may be stored for long periods and hatched on demand to provide a convenient form of live feed for larval fish and crustaceans
Crustacean
Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...
. Nauplii of the brine shrimp constitute the most widely used food item, and over 2000 tonnes of dry brine shrimp cysts are marketed worldwide annually. In addition, the resilience of brine shrimp makes them ideal animals for running biological toxicity assays and is now one of the standard organisms for testing the toxicity
Toxicology testing
Toxicology testing, also known as safety testing, or toxicity testing, is conducted by pharmaceutical companies testing drugs, or by contract animal testing facilities such as Huntingdon Life Sciences and Inveresk Research International on behalf of a wide variety of customers, including the...
of chemicals.
Fish farm owners search for a cost-effective, easy to use, and available food that is preferred by the fish. From cysts, brine shrimp nauplii can readily to be used to feed to fish and crustacean larvae just after one-day incubation
Hatchery
A hatchery is a facility where eggs are hatched under artificial conditions, especially those of fish or poultry. It may be used for ex-situ conservation purposes, i.e. to breed rare or endangered species under controlled conditions; alternatively, it may be for economic reasons A hatchery is a...
. Instar
Instar
An instar is a developmental stage of arthropods, such as insects, between each molt , until sexual maturity is reached. Arthropods must shed the exoskeleton in order to grow or assume a new form. Differences between instars can often be seen in altered body proportions, colors, patterns, or...
I (the nauplii that just hatched and with large yolk reserves in their body) and instar II nauplii (the nauplii after first moult and with functional digestive tracts) are more wildly used in aquaculture, for the reasons they are easy for operation, nutrients rich, and of small size which makes them suitable for feeding fish and crustacean larvae live or after drying.
Diet
Phytoplankton
Phytoplankton are the autotrophic component of the plankton community. The name comes from the Greek words φυτόν , meaning "plant", and πλαγκτός , meaning "wanderer" or "drifter". Most phytoplankton are too small to be individually seen with the unaided eye...
algae
Algae
Algae are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms, such as the giant kelps that grow to 65 meters in length. They are photosynthetic like plants, and "simple" because their tissues are not organized into the many...
. Cultured brine shrimp can also be fed particulate foods including yeast
Yeast
Yeasts are eukaryotic micro-organisms classified in the kingdom Fungi, with 1,500 species currently described estimated to be only 1% of all fungal species. Most reproduce asexually by mitosis, and many do so by an asymmetric division process called budding...
, wheat
Wheat
Wheat is a cereal grain, originally from the Levant region of the Near East, but now cultivated worldwide. In 2007 world production of wheat was 607 million tons, making it the third most-produced cereal after maize and rice...
flour
Flour
Flour is a powder which is made by grinding cereal grains, other seeds or roots . It is the main ingredient of bread, which is a staple food for many cultures, making the availability of adequate supplies of flour a major economic and political issue at various times throughout history...
, soybean
Soybean
The soybean or soya bean is a species of legume native to East Asia, widely grown for its edible bean which has numerous uses...
powder
Powder (substance)
A powder is a dry,thick bulk solid composed of a large number of very fine particles that may flow freely when shaken or tilted. Powders are a special sub-class of granular materials, although the terms powder and granular are sometimes used to distinguish separate classes of material...
or egg yolk
Egg yolk
An egg yolk is a part of an egg which feeds the developing embryo. The egg yolk is suspended in the egg white by one or two spiral bands of tissue called the chalazae...
.
Reproduction
Adult female brine shrimp ovulate approximately every 140 hours. In favourable conditions, the female brine shrimp can product eggs that almost immediately hatch. While in extreme conditions, such as low oxygen level or salinity above 150‰, female brine shrimp produce eggs with a chorion coatingChorion
The chorion is one of the membranes that exist during pregnancy between the developing fetus and mother. It is formed by extraembryonic mesoderm and the two layers of trophoblast and surrounds the embryo and other membranes...
which has a brown colour. These eggs, also known as cysts, are metabolically
Metabolism
Metabolism is the set of chemical reactions that happen in the cells of living organisms to sustain life. These processes allow organisms to grow and reproduce, maintain their structures, and respond to their environments. Metabolism is usually divided into two categories...
inactive and can remain in total stasis for two years while in dry oxygen-free conditions, even at temperatures below freezing. This characteristic is called cryptobiosis
Cryptobiosis
Cryptobiosis is an ametabolic state of life entered by an organism in response to adverse environmental conditions such as desiccation, freezing, and oxygen deficiency. In the cryptobiotic state, all metabolic procedures stop, preventing reproduction, development, and repair...
, meaning "hidden life". While in cryptobiosis, brine shrimp eggs can survive temperatures of liquid air
Liquid air
Liquid air is air that has been cooled to very low temperatures so that it has condensed to a pale blue mobile liquid. To protect it from room temperature, it must be kept in a vacuum flask. Liquid air can absorb heat rapidly and revert to its gaseous state...
(-190 C) and a small percentage can survive above boiling temperature (105 °C or 221 °F) for up to two hours.
Once placed in briny (salt) water (>5‰), the eggs hatch within a few hours. The nauplii, or larvae, are less than 0.4 mm in length when they first hatch. Brine shrimp have a biological life cycle
Biological life cycle
A life cycle is a period involving all different generations of a species succeeding each other through means of reproduction, whether through asexual reproduction or sexual reproduction...
of one year.
Nutritional benefits
Since no artificial feedCompound feed
Compound feeds are feedstuffs that are blended from various raw materials and additives. These blends are formulated according to the specific requirements of the target animal...
formulation is yet available to completely substitute for brine shrimp, feeding live prey to young fish and crustacean larvae still remains essential in commercial hatchery
Fish hatchery
A fish hatchery is a "place for artificial breeding, hatching and rearing through the early life stages of animals, finfish and shellfish in particular". Hatcheries produce larval and juvenile fish primarily to support the aquaculture industry where they are transferred to on-growing systems...
operation. The nutritional properties of newly hatched brine shrimp are high in lipid
Lipid
Lipids constitute a broad group of naturally occurring molecules that include fats, waxes, sterols, fat-soluble vitamins , monoglycerides, diglycerides, triglycerides, phospholipids, and others...
s and unsaturated fatty acids
Fatty acid
In chemistry, especially biochemistry, a fatty acid is a carboxylic acid with a long unbranched aliphatic tail , which is either saturated or unsaturated. Most naturally occurring fatty acids have a chain of an even number of carbon atoms, from 4 to 28. Fatty acids are usually derived from...
(but low in calcium
Calcium
Calcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft gray alkaline earth metal, and is the fifth-most-abundant element by mass in the Earth's crust...
). Dried brine shrimp nauplii contain 37%–71% protein, 12%–30% lipid, 11%–23% carbohydrate, and 4%–21% ash.
The fatty acid compositions of the nauplii are highly environmentally determined. Also the nutritional quality of commercially available brine shrimp strains being relatively poor in eicosapentaenoic acid
Eicosapentaenoic acid
Eicosapentaenoic acid is an omega-3 fatty acid. In physiological literature, it is given the name 20:5. It also has the trivial name timnodonic acid...
(EPA, 20:5n-3), and especially docosahexaenoic acid
Docosahexaenoic acid
Docosahexaenoic acid is an omega-3 fatty acid that is a primary structural component of the human brain and retina. In chemical structure, DHA is a carboxylic acid with a 22-carbon chain and six cis double bonds; the first double bond is located at the third carbon from the omega end...
(DHA, 22:6n-3). Since these components are critical for the larvae development, it is common practice to feed this live prey with emulsions of marine oils
Fish oil
Fish oil is oil derived from the tissues of oily fish. Fish oils contain the omega-3 fatty acids eicosapentaenoic acid , and docosahexaenoic acid , precursors of certain eicosanoids that are known to reduce inflammation throughout the body, and are thought to have many health benefits.Fish do not...
that are rich in the EPA and DHA, which is referred as enrichment
Food fortification
Food fortification or enrichment is the process of adding micronutrients to food. It can be purely a commercial choice to provide extra nutrients in a food, or sometimes it is a public health policy which aims to reduce numbers of people with dietary deficiencies in a population.Diets that lack...
processes.
Industrial hatchery
Since the development of commercial marine fish culture in the late 1970s, the demand for brine shrimp cysts has gradually increased from a few tonnes to approximately 800 tonnes per annum, representing approximately 40% of the total aquaculture demand for feeds for early stages. The price of the cysts varies during the last a few decades depending on both demand and the quality of the cysts. During the last 25 years, the Great Salt LakeGreat Salt Lake
The Great Salt Lake, located in the northern part of the U.S. state of Utah, is the largest salt water lake in the western hemisphere, the fourth-largest terminal lake in the world. In an average year the lake covers an area of around , but the lake's size fluctuates substantially due to its...
in the USA
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
has been the major supplier of brine shrimp cysts to the world aquaculture industry and the subject of numerous speculations regarding its capacity to sustain a growing aquaculture industry. However, due to the unpredictable fluctuation of the cyst yield from Great Salt Lake, there are other sites for cyst production, such as lake Urmia
Lake Urmia
Lake Urmia , ancient name: Lake Matiene) is a salt lake in northwestern Iran, near Iran's border with Turkey. The lake is between the Iranian provinces of East Azerbaijan and West Azerbaijan, west of the southern portion of the similarly shaped Caspian Sea...
in Iran, Aibi Lake in China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
, Bolshoye Yarovoye
Yarovoye
Yarovoye is a town in Altai Krai, Russia, located on the north shore of Lake Bolshoye Yarovoye west of Barnaul. Population: Yarovoye was established in 1943 and was granted town status in 1993....
in Siberia
Siberia
Siberia is an extensive region constituting almost all of Northern Asia. Comprising the central and eastern portion of the Russian Federation, it was part of the Soviet Union from its beginning, as its predecessor states, the Tsardom of Russia and the Russian Empire, conquered it during the 16th...
, Kara Bogaz Gol in Turkmenistan
Turkmenistan
Turkmenistan , formerly also known as Turkmenia is one of the Turkic states in Central Asia. Until 1991, it was a constituent republic of the Soviet Union, the Turkmen Soviet Socialist Republic . Turkmenistan is one of the six independent Turkic states...
, and several lakes in Kazakhstan
Kazakhstan
Kazakhstan , officially the Republic of Kazakhstan, is a transcontinental country in Central Asia and Eastern Europe. Ranked as the ninth largest country in the world, it is also the world's largest landlocked country; its territory of is greater than Western Europe...
.
Although hatchery process of brine shrimp are relative simple and easy to operate, a series of factors need to be controlled and monitored to make optimal use of the cysts. The critical factors are light, temperature, salinity
Salinity
Salinity is the saltiness or dissolved salt content of a body of water. It is a general term used to describe the levels of different salts such as sodium chloride, magnesium and calcium sulfates, and bicarbonates...
, oxygen level, pH
PH
In chemistry, pH is a measure of the acidity or basicity of an aqueous solution. Pure water is said to be neutral, with a pH close to 7.0 at . Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline...
and cyst density, which vary between different brine shrimp strains. Hatching quality can be described by hatching efficiency (number of nauplii per gram of cysts), hatching percentage or hatching synchrony
Synchronization
Synchronization is timekeeping which requires the coordination of events to operate a system in unison. The familiar conductor of an orchestra serves to keep the orchestra in time....
(time between first and last hatching cysts).
There are six stages in the hatching and development of brine shrimp industrial hatchery.
After hatching, and prior to feeding them to the fish or crustacean larvae, brine shrimp nauplii should be separated from the hatching wastes. After switching off the aeration
Aeration
Aeration is the process by which air is circulated through, mixed with or dissolved in a liquid or substance.-Aeration of liquids:-Methods:Aeration of liquids is achieved by:...
in the hatching tank, cyst shells will float and nauplii will concentrate at the bottom of the tank. The nauplii are further concentrated in a concentrator
Concentrator
In telecommunication, the term concentrator has the following meanings:# In data transmission, a functional unit that permits a common path to handle more data sources than there are channels currently available within the path...
rinse and separated from the cysts.
The enrichment process, if needed, generally occurs after the nauplii develop a digestive tract
Digestion
Digestion is the mechanical and chemical breakdown of food into smaller components that are more easily absorbed into a blood stream, for instance. Digestion is a form of catabolism: a breakdown of large food molecules to smaller ones....
. The three main enrichment approaches are listed below.