Methods of breeding crustacea.
The main requirement for incubation apparatus is the uniform and complete movement of eggs throughout the entire incubation period. Many aquarists overlook this, trying to breed the crustacean in all kinds of jars with a flat and wide bottom. The mistake of many aquarists trying to get a good yield of crustacea is excessive salinization of the solution.
1. Pour 0.5 l of saline solution (20 g of table salt per 0.5 l of water) into a 1-liter bottle, add a teaspoon (without a mound) of Artemia eggs, and close it with a stopper having 2 holes with plastic tubes passed through them. Put an airstone on one of them at the end immersed in water to the very bottom, and connect the other end to the compressor. Another tube, short, does not reach the water surface and serves to exhaust air. A strong stream of air ensures the mixing of eggs, and so that they do not accumulate near the neck of the bottle, it is shaken from time to time.
Ripening of the first batch of nauplii at a solution temperature of 24-25°C occurs in 36-40 hours. To collect them, turn off the air supply and place the bottle at a slight angle for 4-5 minutes so that the nauplii have time to settle to the bottom. Then insert another stopper with 2 tubes into the bottle, one of which is connected to the compressor and does not reach the water surface. One end of the second tube reaches the bottom of the bottle, and the other is led to a glass jar covered with a fine mesh. Turn on the compressor, and the water flows into the jar, while the nauplii remain on the mesh.
After washing with water, they can be fed to fish. The solution from the jar is poured back into the bottle, and the operation can be repeated 1-2 more times. A fresh solution is prepared for each new batch of eggs. The disadvantage of this method is not a very high percentage of hatching from eggs and the inability to completely get rid of eggshells, which, remaining in the net and entering the fry’s intestine, can cause unpleasant consequences.
2. The breeding vessel is glued from an opaque material (viniplast or painted plexiglass), and only the side and back walls of chamber “2” are made of transparent plexiglass. Eggs are loaded into chamber “1”, and the newly hatched nauplii penetrate through the lower slot and holes in the intermediate wall into the illuminated chamber “2”, from where they are caught with a net. This transition is especially intense if aeration is turned off for a few minutes.
3. In a three-liter jar of aquarium water, dissolve 3 tablespoons of non-iodized salt and 1 tablespoon of baking soda. Place 0.5-2 teaspoons of eggs there, depending on the need for 
feed. Cover with a plastic lid with 2 holes for inserting the compressor hose and the air outlet tube. The water temperature is maintained at 26-30°C; at a lower temperature, the hatching of nauplii is prolonged, and hatchability worsens. Round-the-clock lighting and weak aeration by a compressor through an airstone are desirable so that the eggs are constantly in motion and do not accumulate at the bottom. It is possible to continuously introduce new portions of Artemia eggs into the incubator.
Hatching begins in 18-20 hours if the jar is in a warm place. 15 minutes after turning off the compressor, dead specimens and shells accumulate near the surface, eggs are at the bottom, and live Artemia are in the bottom layer. When catching them, their reaction to light should be used by shading most of the jar. They are sucked out with a siphon — a glass tube with a bulb attached to it, washed with water in a very dense nylon net, and fed to fish.
4. One of the simplest and most convenient tools in operation is the Weis apparatus, into which air is supplied. A likeness of the Weis apparatus can be easily made at home from 2-3 liter plastic bottles. The bottom of the bottle is cut off to serve as a lid. An air supply tube is passed through a hole in the lid. For continuous production, one or several bottles can be mounted in a stand. Harvesting of nauplii is carried out with a siphon or through a tube with a valve hermetically embedded in the bottle stopper; silicone sealant can be used for this. The optimal temperature for hatching nauplii is considered to be 28°C, although it happens faster and more uniformly at 30-31°C.
The bulk emerges a day or two after the start of incubation. To enrich the incubation medium with oxygen and remove carbon dioxide, intensive aeration with air through an airstone is used. The air flow must be such that the cysts are constantly in the thickness of the solution. During the first day, the cyst absorbs water 1.4 times its own initial weight, after which the embryo revives and its development resumes. A slit forms in the cyst, through which the embryo, surrounded by the hatching membrane, gradually emerges.
After a few hours, it is completely released, but is still in the hatching membrane, which is connected to an empty shell hanging like a ball above the teardrop-shaped embryo (“parachutist” is what practitioners call this very characteristic stage of development, serving as a reliable sign of a successful incubation process). Soon the hatching membrane ruptures, and the nauplius begins free swimming. Until the first molt, within 10-12 hours, the nauplius does not feed: the mouth and anus are closed, and the digestive system does not work. Half a day later, it enters the second larval stage and begins to filter out and absorb unicellular algae, bacteria, and detritus. In the process of growth within 8 days, up to 15 molts take place. Artemia lives up to 6 months.
5. Artemia incubator. It is a rectangular vessel glued from plexiglass. The bottom is heavily slanted. A solution of table salt is poured into the vessel. Concentration — a full 
tablespoon of salt per 1 liter of water. Aeration is carried out using an airstone. The intensity of aeration is chosen so that all eggs are evenly mixed and do not settle to the bottom. From 0.2 to 0.5 teaspoons of eggs are poured into 1 liter of saline solution. Depending on their quality and the aquarist’s tasks, more can be added, but in this case, there is a danger of poisoning the incubator with metabolic products.
The incubator must be illuminated around the clock. It is advisable to place a 15-25 Watt incandescent lamp on the side. Then it also works as a heater. If it is cold in the room, the incubators are placed in an insulated box. By moving the bulb away or closer, you can select the desired temperature in the incubator and do without a special thermostat. The optimal incubation temperature is 28-30°C. At 28°C, larval hatching begins in 1 day, and mass appearance of nauplii suitable for feeding occurs in 30-48 hours. At a higher temperature, the process goes faster, and the larvae hatch more uniformly and, accordingly, finish faster.
6. Three liters of transparent old aquarium water are poured into a glass crystallizer with a diameter of 40 centimeters. Then, in a separate jar — one and a half liters of fresh tap water heated to a temperature of 50-60 degrees. Table salt is dissolved in this water — six tablespoons without a mound. The salt solution is filtered through cotton wool. The filtrate is poured into the aquarium water, after which the vessel is placed in a warm place so that the water temperature is constantly maintained at 24-26 degrees. When the water surface completely calms down, half a tablespoon (or less) of eggs is lowered onto the surface. It is advisable to place them in a floating dry food feeder; in this case, the eggs do not stick to the walls of the jar, and it will be easier to catch them later.
The first larvae hatch in 22-24 hours, and this is where many amateurs make a mistake. Eager to examine them, they move the jar, or even move it from place to place entirely. In this case, a mass of larvae that have begun hatching but have not yet freed themselves from the eggshells sink to the bottom and die there (probably from lack of oxygen). The larva must hatch on the surface, in direct contact with air. After 1.5 days, the vast majority of larvae have already hatched, and for better oxygen supply to the water, the jar can be moved to a cooler place or weak air aeration can be arranged.
7. To obtain nauplii, an incubator is made. It is an isothermal box in which two vessels with a total capacity of 1.5 l are installed. The body is a box whose side walls and top cover are made of 3 mm plywood, and the base is a piece of board 25 mm thick. The entire frame is covered with a double layer of plastic film, and the front part is made hinged. The tightness of the front part’s fit to the side walls and base is ensured by a sealing rubber.
1-liter bottles are used as containers. The containers are installed in the incubator body with the neck down, next to the side walls, to which they are attached with an elastic band. Two holes with a diameter of 14 mm are drilled in the top cover of the incubator body to install a funnel and a control thermometer. Holes with a diameter of 4 mm are made in the bottle neck stoppers, through which PVC tubes with regular airstones pass. A regular 15-watt lamp serves as the heating element in the incubator; it is suspended in the free space between the containers, the socket is standard, the wire is stranded, flexible. The distance from the container to the lamp bulb is about 25 mm. With the help of such a simple heater, the solution temperature is maintained within 27-29°C.
In the base board of the incubator body, along the installation axis of the containers, 20 mm diameter recesses are drilled to 3/4 of the base thickness; through-holes with a diameter of 6 mm are drilled to them from the end side of the board. A PVC tube connecting the airstones to the compressor is passed through the end holes and axial recesses. The holes in the bottom of the incubator eliminate tube kinking and ensure normal air supply from the compressor. The compressor serves both the incubator and the aquarium facilities simultaneously. Working with the incubator is simple. It comes down to washing the containers, filling them with solution, introducing Artemia eggs, and extracting the crustacean. The solution and Artemia eggs are introduced through the holes in the top cover using a small funnel.
Feeding fish with Artemia. Branchiopod crustaceans, freshwater fairy shrimp.
Artemia. Branchiopod crustaceans (Artemia salina). Decapsulation of Artemia eggs. 
