Key Technical Points and Methods for Brine Shrimp Culture Explained

Brine shrimp is a high-quality live bait with very rich nutritional value, especially suitable for feeding artificially cultured fish and shrimp. It is widely distributed, mainly in salt pans or salt lakes on land. Brine shrimp is widely used in aquaculture, so it has very good prospects for culture.

Brine Shrimp Culture Technology

1. Preparations in Advance

Hatching brine shrimp dormant eggs requires water of a specific salinity, so the water used for hatching must strictly follow the requirements. Since the salinity required for hatching is only one-half to one-third that of natural seawater, the simplest method is to mix natural seawater with freshwater at a ratio of 1:1 or 1:2. When natural seawater is unavailable, commercially available artificial sea salt can also be used to first prepare artificial seawater according to the recommended dosage, and then mix it with freshwater.

2. Hatching Methods

1. Brine shrimp eggs are stored refrigerated, so before hatching they should be placed in a dry environment at room temperature for about one week in advance, otherwise the hatching rate will be lower.

2. For small-scale hatching, a small container that is narrow at the bottom and wide at the top can be used as a hatchery, filled with light saltwater. The water used for hatching is just the opposite of the water used for culture: very dilute seawater should be used, about half seawater and half freshwater, for the highest hatching rate. Before use, it should be boiled for disinfection to prevent microorganisms from being introduced.

3. If the water temperature can be maintained at 20-30 degrees, the hatching rate will be better, and lower temperatures will not have a serious effect. Install an air inlet at the bottom of the container, and aerate lightly so that bubbles rise slowly from the bottom.

4. Nauplii will swim in the middle layer of the water, empty egg shells float on the surface, and dead eggs and unhatched eggs sink to the bottom. Use a pipette to draw out the water from the middle layer containing nauplii, and pour it directly into the culture tank. After that, more light saltwater can be added to the hatchery and aeration continued for one or two more days, and more nauplii will still hatch out.

3. Feeding

The best food for brine shrimp is the planktonic algae in seawater. After exposure to sunlight, large amounts of algae will naturally grow in seawater for brine shrimp to feed on, so generally no feeding is needed. However, under conditions of higher culture density, other tiny organic matter can also be supplemented to increase the number of brine shrimp. In a home culture environment, organic wastewater such as rice-washing water or milk can be continuously added to the water. But it should be noted that when supplementing these wastewaters with very high organic content, the principle of using less rather than more should be adhered to, and it should be controlled to a level where the water quality does not deteriorate and become turbid. Never use excessive amounts.

4. Timely Harvesting

Brine shrimp nauplii can mature after more than ten days of feeding. Most adult brine shrimp are female, and mature females all carry egg sacs. At this time their nutritional value is the highest, and they can be harvested.

If a tank contains brine shrimp of different sizes, or if some brine shrimp have already released young, when harvesting it is best to use a wide-mesh dip net, catching the large ones and letting the small ones go, only scooping out the mature brine shrimp and leaving the small ones in the tank to grow.

Ecological Habits of Brine Shrimp

1. Strong adaptability. Brine shrimp have a very strong ability to adapt to temperature, salinity, and dissolved oxygen. The temperature range they can tolerate is between 6 and 35°C; salinity is from 5 parts per thousand to 340 parts per thousand; and dissolved oxygen is between 1 and 150 ppm.

2. Wide distribution. The distribution of brine shrimp is global, all in salt lakes and saline ponds. Brine shrimp are rarely found in water below a salinity of 45 parts per thousand. Brine shrimp can survive in water with a salinity of 300 parts per thousand. Because under high salinity there are very few predators and competitors, their populations can maintain very high densities.

3. Dormant eggs. Brine shrimp produce dormant eggs with a diameter of about 200-280 micrometers at a salinity above 100 parts per thousand, commonly known as durable eggs. Durable eggs are grayish brown, have a hard shell, and float on the water surface or are suspended in the water. They can survive harsh environments such as oxygen deprivation, cold, and dryness in the sludge at the bottom.

4. Durable eggs. Brine shrimp are dioecious, and their reproductive methods can be divided into two types: oviparous and ovoviviparous. Under poor conditions such as high salinity and low dissolved oxygen, oviparity is induced, forming durable eggs. Under low salinity and high dissolved oxygen, fertilized eggs directly develop into nauplii.

Methods for Decapsulating Brine Shrimp Durable Eggs

After the hard shells of brine shrimp durable eggs are swallowed by fry, they can block the digestive tract and even cause the death of the seedlings, so mixing egg shells into the nauplii and putting them into the seedling pond must be avoided as much as possible. To reduce the impact of egg shells, decapsulation can be carried out according to the following steps.

1. Soak the durable eggs in seawater for half an hour first.

2. Collect the durable eggs with filter cloth and remove the water.

3. Add 2 parts per thousand bleach solution pre-cooled to 15-20°C.

4. Aerate for 5-7 minutes, or until the egg shells change from brown to orange-red.

5. Filter and collect, then rinse with freshwater.

6. Add 3 grams of Na2S2O3 per liter to neutralize.

7. Aerate for 5-7 minutes.

8. Filter and collect, then rinse with freshwater.

9. Hatch the eggs according to the usual method.

After decapsulation treatment, the hard shells of the durable eggs are dissolved, thus preventing the seedlings from swallowing the hard shells and dying.

Selecting Brine Shrimp Eggs

1. Good brine shrimp eggs should be brown in color and glossy, feel dry to the touch, have no musty or fishy odor, and contain relatively little mud and sand.

2. Use two pieces of glass to crush the eggs, count the number of eggs with oil droplets and eggs without oil droplets among the broken eggs, and determine the ratio of good eggs to bad eggs. If there are more eggs without oil droplets, the reason may be that a large amount of egg shells is mixed in, and special attention should be paid when purchasing.

3. Observe with a magnifying glass and roughly estimate the proportion of round, shriveled, and damaged eggs. Sunken eggs are mostly caused by dehydration; if they are not damaged, they are good eggs.

4. If conditions permit, samples can be taken for hatching. For the same number of nauplii hatched, the brine shrimp eggs that require a shorter time are better. Such eggs have relatively uniform hatching times for the larvae, making collection easier.

Brine shrimp are a relatively easy shrimp to raise. Brine shrimp also have an extremely wide temperature tolerance range, they do not eat much, and the hatching of brine shrimp eggs and the growth of brine shrimp are basically one process.