Cultivation of Artemia

* Artemia, also known as brine worm, brine shrimp, brine shrimp, also called salt worm, is a small crustacean distributed worldwide.

* my country has used Artemia nauplii as feed for marine juveniles since 1958.

* In all field resource surveys since the founding of the People's Republic of China, my country is also a country with large Artemia resources.

1. The biology of Artemia

* (1) Reproductive habits

* Artemia reproduces in both parthenogenesis (also known as parthenogenesis) and bisexual reproduction.

* Parthenogenesis: under good environmental conditions;

* Bisexual reproduction: under adverse environmental conditions.

* There are also some strains that are only parthenogenetic or bisexual.

* Reproduction: Female 5-10 times/life, 2-300 eggs per pregnancy

(Generally 80-150), 30-40 each time indoors.

(2) The life history of Artemia

* Artemia undergoes metamorphosis during its development, going through stages such as egg, nauplii, post-nauplii, larvae and adults.

* Development: egg → nauplii → adult? (shell growth);

* Lifespan: 2-3 months, up to 9 months.

* Artemia grows by molting (12-15 times in a lifetime), and develops metamorphosis. From the nauplii hatched from the eggs to the adult stage, the individual differences are very large.

* The newly hatched nauplii have a large amount of yolk within 1-2 days, which is rich in nutrients such as protein and fat, and is a good bait for fish, shrimp and crab larvae.

1. Artemia winter eggshell is thick, gray-brown, 200-280 ?m in diameter

2. nauplii

* Initial hatching:

* Body length 0.3-0.4mm

* Body width 0.25-0.3mm

* 3 pairs of appendages, one eye

3. Adult Artemia

* Total length 1.2-1.5cm, separate head, chest and abdomen;

* Head: 5 pairs of appendages

* Chest: 11 pairs of appendages

* Abdomen: without appendages

(3) Ecological conditions

* 1. Distribution: extensive, our country is rich in resources

* Distributed all over the world except the north and south poles. Mainly distributed in salt lakes or salt pans with high salinity;

* my country is rich in resources in Hebei, Liaoning, Shandong and Inner Mongolia.

2. Salinity

*Life 10-242

* Tolerable 1-340

* Optimum 30-50

* Salinity has a significant effect on the individual size and body color of Artemia. Under the condition of salinity of 30-50, Artemia is large and light in color. The higher the salinity, the smaller the individual and the darker the body color.

3. Temperature

* Artemia has a wide range of adaptation to temperature, survival is -3~42°C, growth is 15-35°C, and the optimum incubation temperature is 30°C. Less than 15 ℃, slow growth and development.

* Able to withstand sudden changes in temperature. For example, if the oviparous females cultured at 25°C are immediately transferred to -2°C for 2 days, Artemia can still survive.

4. Low dissolved oxygen consumption, more than 1mg/L can

5. pH

Adapt to 7.5-8.5 Adapt to 7.5-8.5

6. Bait

* Typical filter feeder, omnivorous (bacteria, yeast, algae, small protozoa, organic detritus);

* The selectivity of the bait is poor, and the size of the bait is less than 50um.

* 7. The moving larvae have strong phototaxis and can be collected by light induction.

2. Treatment of Artemia eggs

(?1) Saturated brine method - specific gravity method:

Eggs——saturated salt water→sinking to the bottom: sand and stone with a large specific gravity.

Floating → fresh water → floating: grass and other impurities.

???

Bottom sinking: eggs → fish out → sea water washing

Dehydration, air drying → sieving → processing, packaging (large plastic drum or iron can packaging).

(2) Panning method:

* ①Coarse mesh filter;

* ②Using 40-60 mesh net to wash (remove large impurities);

* ③Use 80-100 mesh net to wash (remove small impurities);

* ④ Seawater washing → dehydration, air drying → sieving → processing and packaging.

3. Storage

* (1) Low temperature;

* (2) Vacuum or nitrogen filling;

* (3) In saturated brine.

2) Selection of dormant eggs

* --Look at the place of origin: Tianjin and the United States are better.

* --Understand the treatment technology: seawater should be washed in the treatment, and low temperature treatment is required.

* 1. Judgment of appearance quality

* ①Color and odor: It is tan, shiny, and does not agglomerate by hand.

* Can be dispersed, no musty smell in the nose;

* ②Sediment content: judged by clean saturated brine, sedimentation at the bottom of the test tube

* Too many things and turbid water is not good;

* ③ broken shell broken shell and empty shell: use a magnifying glass or microscope to observe: it is round or deflated,

* With or without broken shell and proportion.

* ④Size: determine the number of eggs per gram;

* ⑤ Counting oil droplets: Take 10 eggs and squeeze them with two glass slides to see if there are oil droplets.

* Those with oil droplets are good eggs;??

* ⑥Bacterial content: microbial culture.

4. Quality identification standard

* (Comparison under the conditions of salinity 35‰ and temperature 25℃)

* ①Hatch rate: %

* ② Hatching efficiency: the number of nauplii/g;

* ③ Hatching speed: T0 (the first larvae appear), T90 (90% hatched);

* T10 (10% hatched); T0 is about 20-26 hours, the shorter the better, the difference between T10 and T90 indicates the synchronization of incubation, the closer it is, the better.

* ④ Hatching yield: 180,000-250,000 grains/g, referring to the total dry weight of hatched nauplii;

* ⑤Moisture content: Generally, the water content is 5-8%;

* ⑥ Nutritional value - breeding effect. Such as: seawater eggs are better than salt lake eggs.

(3) Shelling of dormant eggs

* 1. The principle of shelling:

* Artemia eggshell is composed of lipoprotein + heme, which can be oxidized by hypochlorite.

* 2. The meaning of artemia egg shelling:

> ①Can play a role in disinfection;

> ②Prevent water pollution;

> ③Increase hatching rate;

> ④Increase the energy of nauplii;

> ⑤There is no need to separate the eggshell, which saves labor and time, and brings convenience to production.

3. The process of shelling Artemia eggs:

* Water treatment (1h) Washing and filtering Prepare shelling solution Shelling (6-15min) Washing and filtering Dechlorination (1-2%Na2S2O3) Washing and filtering.

* Preparation of shelling solution: NaOH 0.13g/g egg (sodium hypochlorite) and Na2CO3 1g/g egg (calcium hypochlorite).

* Each gram of available chlorine (hypochlorite) can oxidize 2-2.5g eggshells.

* Total volume of dehulling solution: 13ml/g egg.

(4) Incubation of dormant eggs

* ⑴ temperature: optimum 25-30 ℃; water temperature <7 ℃, > 45 ℃ do not hatch;

* (2) Salinity: Optimum 28-30, >30 slows down hatching and reduces hatching rate; ?

* ⑶pH: 8-9 (alkaline) is better, can activate hatching enzymes;

PH can be increased with 1g/L NaHCO3 or 65mg/L CaO;

* ⑷ Light: only about half hatch in the dark, and hatch again after light;

To continuously 1000-2000lx lighting effect is good;

* ⑸ Dissolved oxygen: >3ppm, it is better to be close to saturation.

* 1. Incubation conditions

2. Incubation method

* ⑴ preferred: bulk to remove impurities, not canned;

* ? ⑵ cleaning, soaking and disinfection: there are impurities, bacteria, viruses, parasites on the shell;

* Cleaning: Use tap water to clean impurities;

* Soaking: Put it in a 120-mesh mesh bag and soak it in sea water for 15 minutes to soften the eggshell;

* Disinfection: its method:

* A, 20-50ppm formalin soak for 30 minutes;

* B, 15-30ppm potassium permanganate soak for 5 minutes;

* C, 20ppm bleaching powder soak for 30 minutes;

* D. Iodine solution: 2-10ppm, soak for 30 minutes.

* ⑶ Incubation density: 2-3 grams/liter, 4-6 cans/m3.

3. Incubation bucket and collection method

⑴ Incubation bucket: 1-2 air stones/m2, one heating rod, black or transparent glass fiber reinforced plastic bucket, the bottom is transparent or white, black lid (cover when collecting), and 1-2 30-40W fluorescent lamps are installed on it.

(2) Collection: Incubation for 24-36 hours

A. Remove the air stone and heating rod, and cover with the black cover;

B. Use a lamp on the bottom to lure the nauplii;

C. 120 mesh mesh bags are collected at the outlet.