Sewing a net for catching Cyclops Daphnia dust. How to make a net for catching daphnia. Life-size Daphnia in a two-liter container

Suborder: Cladocera Latreille, 1829 = Cladocera

Catching daphnia in nature.

They catch daphnia with a net. For this you need a special net - with a long handle (up to 2-3 meters, usually made of several screwed sections), with a diameter of about 25-30 cm and a fabric cone about 50-60 cm long with a rounded end. The net ring is made of durable material, for example stainless wire with a diameter of 3-5mm. If you make it from a thinner one, it will bend easily, and considering the possible snags on the bottom... But the most difficult thing is to choose the fabric for the net. Here, synthetic materials are preferable, such as nylon, which do not rot from prolonged contact with water. The mesh size of the net depends on what you are going to catch; very fine fabric greatly slows down the net in the water, so it is better to have several interchangeable rings with different fabrics for catching food of different sizes.

They operate the net calmly, smoothly, without much effort, moving it with a figure of eight in places where daphnia accumulate. We did it a couple of times - took it out, shook out the catch, and began to fish further. If you push a full net, many daphnia will crumple and die, so it is better to take it out more often with small portions of prey. Otherwise, greed, you know, does not lead to good. For fishing, it is better to prefer smaller bodies of water, for example, puddles - there daphnia are more accustomed to oxygen starvation and will more easily endure further transportation. True, it is difficult to catch in small puddles with a standard net; there you have to use a net with a shorter cone - otherwise it begins to cling to the bottom and create turbidity. In order not to catch hydra with daphnia, you should try to catch prey away from thickets of aquatic plants or objects in the water to which it can attach. And in no case is it recommended to catch food in reservoirs where fish live - with such food you can easily introduce pathogens of various diseases.

The caught daphnia are placed in a container - a can or a special can for transportation. Before pouring, it is advisable to strain the catch through a thin mesh to remove any trapped debris and any large unwanted guests - swimming beetles or large dragonfly larvae. It is very desirable to have a battery-powered compressor in the transport container - it will keep most of the catch alive during the journey home.

At home, caught daphnia are poured into a wide flat vessel, for example a white enamel basin. There, for some time, all the unwanted organisms settle on the bottom and walls; on a white background it is easy to spot the larvae of dragonflies and leeches, and everything else that has nothing to do with daphnia. There, at the bottom, dead crustaceans accumulate. When feeding, daphnia are caught with a net; the water in which they are located cannot be poured into the aquarium!

Crustaceans (Crustacea). Representatives of the class of crustaceans, along with bloodworms, occupy a leading position in feeding aquarium fish. Species of two orders are especially important: cladocera and copepods (Copepoda).

All cladocerans are usually called Daphnia. The body of most of them is enclosed in a bicuspid chitinous shell, fastened on the back and diverging on the ventral side. Branched antennae extend from the head, and when struck by them, the crustaceans make characteristic pushes: with each swing, the body moves forward and upward, then slowly lowers, after which another push follows. For such spasmodic movement they received the name water fleas. On the ventral side of the body, under the shell, there are 4-6 pairs of thoracic legs with gills that carry out breathing.

Cladocerans are found in a wide variety of water bodies, especially in small ponds, puddles, ditches, and pits. Sometimes there are so many of them that the water turns reddish, greenish or grayish.

Cladocerans feed on microorganisms: algae, bacteria, ciliates. They are very sensitive to light: when the light dims, they rise to the surface, and vice versa.

Throughout the summer, females reproduce virginally. In the brood chamber, located on the back, unfertilized eggs develop, from which young females hatch. Only towards the end of summer do some eggs hatch into males. After they fertilize the females, eggs are formed (usually no more than two), rich in yolk and completely opaque, they are enclosed in a dense shell. The shell containing the eggs forms a saddle, or ephippium. Ephippia swim freely or sink to the bottom, they tolerate freezing and drying. Dried ephippias, along with dust, are carried by the wind. Warmth and moisture awaken the eggs to life; from them females are hatched, capable of reproducing virginally for many generations.

Rice. 42. Cladocera crustaceans:
a - Daphnia magna, b - Daphnia pulex, c - Daphnia longispina, d - symocephalus, d - moina, f - ceriodaphnia, g - bosmina, h - chidorus, i - sida

Several hundred species of cladocerans are known (Fig. 42), all of them have great variability. Of these, the most common are representatives of the genus Daphnia. This genus contains the most widespread and well-known crustaceans. These include: the largest Daphnia magna(Daphnia magna Straus), reaching 5-6 mm in length; It usually lives in shallow bodies of water (ponds, pits). Very widespread in shallow waters Daphnia pulex(D. pulex De Geer) 3-4mm long. Daphnia longispina(D. Iongispina Muller) lives in both shallow and deep water bodies; it comes in a number of different forms.

Representatives of the genus symocephalus(Simocephalus) - flat crustaceans, often colored red, they are characteristic of stagnant bodies of water; their body length ranges from 2 to 4 mm.

Representatives of the genera are widespread ceriodaphnia(Ceriodaphnia) and moina (Moina).

Of the smaller forms, various representatives of the genus are found in huge quantities bosmin(Bosmina) with long beak-like appendages on the head and Khidorusov(Chidorus), characterized by its round shape.

Copepods (Copepoda) in contrast to cladocerans, most of which are a temporary component of plankton, usually live in water bodies all year round (Fig. 43). Representatives of two genera are of greatest importance for aquarists: diaptomus(Diaptomus) and cyclops(Cyclops). Usually aquarists call all copepods cyclops.

Rice. 43. Copepods;
a - Cyclops, b - Cyclops nauplius, c - Diaptomus

Diaptomus belong to the group of copepods of open waters; they are characterized by “hovering” in the water on long first antennae outstretched to the sides. In contrast, Cyclops are residents of the coastal zone; they move in characteristic leaps with the help of relatively short first antennae and thoracic legs. In both Diaptomus and Cyclops, both sexes always take part in reproduction. The female carries fertilized eggs in special facial sacs attached at the base of the abdomen - one in Diaptomus and two in Cyclops. The eggs develop in egg sacs and larvae emerge from them - nauplii, which are sharply different from adult individuals. Copepods feed on organic remains and small organisms.

Rice. 44. Folding net for catching crustaceans

To catch various small crustaceans and other types of food that make up plankton, a net is needed (Fig. 44); The crustaceans are usually transported in a special vessel - a canna. The net should be light, stainless and suitable for catching crustaceans of various sizes. The most convenient is a net with a diameter of 25-30 cm, made of stainless wire 3-5 mm thick and equipped with a screw thread for connection to the handle (Fig. 45). The handle can be made up of 4-6 screwed elbows (40-50 cm long each), made of duralumin tubes with a diameter of 25-30 mm. By connecting one or another number of elbows, you can use a net to catch crustaceans at greater or lesser depths and at different distances from the shore. A bag 50-60 cm long, rounded at the end, is sewn to the ring. The fabric of the bag should easily allow water to pass through and at the same time not be damaged by dampness. These conditions are best met by mill gas or nylon fabric; in extreme cases, cambric or voile can be used. It is better to have two nets or two removable rings with different fabrics: a bag of more common mill gas, nylon fabric, cambric or maya is pulled onto one ring, trapping both adult crustaceans and the smallest nauplii, rotifers and other small organisms, united under the general name "dust"; another ring, with a rarer mill gas, nylon or marquise, is used in cases where there is no need to extract “dust”. When catching food with such a net, it will be sorted at the same time; Working with a net made of rare fabric is much easier.

Rice. 45. Connection of the ring with the handle of the net

When catching crustaceans, you need to move the net calmly, without using much effort, and take out its contents without waiting until there is too much food in it. Daphnia and Cyclops caught in this way are better preserved.

It is better to catch crustaceans in polluted ponds and small temporary puddles, since here they have adapted to unfavorable conditions and in the future will be easier to transport and will remain alive longer.

When catching crustaceans, it is necessary to take into account that depending on the light, temperature, wind direction, as well as the time of day and year, the crustaceans move first to one shore, then to the other, sometimes they stay in the upper layers of water, sometimes in the middle layers, and often at the very the bottom of the reservoir. Observation, and subsequently experience, makes it possible to quickly detect the place of their greatest concentration. First, you have to do test catches, using a net ten times in different places and placing the contents in a transparent vessel (test tube). Thus, a suitable place with the highest concentration of crustaceans is found.

To avoid introducing infection into your aquarium farm, it is better to catch fish food in reservoirs devoid of fish populations. To avoid collecting hydras, you should catch food away from plants and various objects immersed in water. To catch food in puddles, it is better to use a small net with a short bag.

Caught crustaceans should be strained on the spot through a fine mesh or sieve so that various other aquatic animals and debris do not get into the food. It is especially convenient if a mesh of a suitable shape is mounted in a vessel intended for transporting daphnia and cyclops.

To transport crustaceans, you can use ordinary cans, but it is better to make a canna - a special low vessel with a wide neck. A canna made to suit the size of a suitcase is especially convenient; On top of the remaining free space are placed a folded net with handle arms of appropriate sizes, a glass jar for viewing water samples, and, if there is a need for high concentrations and long-distance transportation of food, a rubber balloon for blowing air through the water. You can transport wet crustaceans alive on wooden frames with a slightly moistened cloth stretched over them, placing them in a thin layer. Such frames can be placed one on top of the other and, tied together, transported as a whole package within one or two hours. You can design a special box or adjust the frames to fit the size of the suitcase. Such a relatively complex device should be made if it is intended to dry daphnia, and for some reason there is no time or opportunity to perform this operation on the shore of a reservoir.

You should not feed your fish freshly caught crustaceans. First, the food must be filtered, and then to store it alive, place it in a wide flat vessel, preferably in a white enamel basin. Here you can easily find various unwanted “guests”: swimming beetles and their larvae, nymphs and larvae of dragonflies, smoothies. The most dangerous enemies of fish - carp-eating crustaceans and hydras - quickly settle on the bottom and walls of the vessel. Water poured into a basin with food reaches room temperature within 1-2 hours. Only after this they begin distributing food.

Fish should be fed crustaceans without the water in which they are kept; To do this, water with crustaceans can be filtered through a net, and, if necessary, through 2-3 nets.

Rice. 46. ​​Sieves for sorting plankton and bloodworms

It’s even better to make special sieves from zinc (Fig. 46) with holes such that the largest crustaceans are retained in the top one, small ones in the second, and “dust” is concentrated in the third. This kind of sieves can be made from a metal tin can with the bottoms cut out, and the mesh is attached to it using a rubber ring. Usually three sieves are sufficient. If any larger animals or plants are found with the food, you can place a fourth sieve with larger holes on top. For the same purpose, a sieve is often installed directly in the canna.

To preserve crustaceans, wide, flat vessels, such as enamel basins, are usually used. The vessel containing the crustaceans should be placed in a cool and dimly lit or dark place. The duration of storage of crustaceans depends on their species, as well as on the concentration. This period can be increased by blowing air through the water or by storing the crustaceans in the refrigerator.

Rice. 47. Vessel for keeping crustaceans

In all cases, when storing live crustaceans, a certain number of them die and fall to the bottom, so you need to periodically remove the dead ones with a pear or pour the top layer of water with live crustaceans with a hose. You can make a special vessel (Fig. 47) with an outlet tube at the bottom, through which to lower dead crustaceans that have fallen to the bottom. Using this tube, the crustaceans are released into sieves for sorting.

Tropical fish cannot eat daphnia, so they are kept in the aquarium all the time, but their excessive quantity leads to the fact that the crustaceans absorb too much oxygen. You can periodically add this type of live food without going beyond a certain density.

Frantisek Gavlena from Czechoslovakia kindly shared his experience of cultivating live daphnia with the author. For this purpose, a swimming pool 25 m long, 120 cm wide and 80 cm deep was built at a fish hatchery in Bratislava. In spring and autumn, the pool is covered with glass, and in winter the water in it is heated. In this basin, sustainable “harvests” are obtained, providing live food for the farmed fish until December. Daphnia can be bred in barrels, vats, 5-liter jars and even glasses.

Of the numerous species of cladocerans, according to the observations of F. Gavlen, Daphnia magna is most suitable for breeding, but satisfactory results are also obtained with Daphnia pulex.

To develop the culture of crustaceans, feed and baker's yeast are used. They are filled with 15 g/m 3 of water, then every other day 7 g/m 3 are added. After 3-5 days, the water turns green (“blooms”). To speed up this process, you can add water from the aquarium where it “bloomed”.

First, daphnia are bred in a 5-liter jar, and then the finished culture is added to large-volume vessels.

Daphnia should be caught in natural reservoirs in the spring or bred from ephippia. Ephippia are collected in the fall from the surface of a reservoir; they can also be obtained under artificial conditions. To do this, you must first reduce and then completely stop feeding daphnia. Usually after a week the culture dies out and a mass of ephippia forms.

The daphnia culture should not be too dense: to begin with, it is enough to plant 40-50 specimens in an 80-100 liter aquarium. Subsequently, the culture is “charged” at the rate of 200 specimens per 1 liter of water. 50 g of daphnia per 1 m 3 are placed in the breeding pool.

The water temperature is maintained at 20-25°, its color should be slightly green or slightly brown. Brown water is an indicator of unfavorable conditions, in which case feeding should be stopped. Usually after a day the water returns to a faint green or brownish color. Otherwise, the culture should be “recharged”.

Once or twice a week, 10 g/m 3 of ammonium nitrate NH 4 N0 3 should be added to the culture. Good results are obtained by adding blood or water in which the meat was washed to the culture.

When breeding daphnia, the best results are obtained if a certain number of tubifex worms with sand are placed in the culture, which serve as constant suppliers of bacteria. If all the specified conditions are met, 40 g/m of daphnia per day is usually obtained. The largest number of daphnia are collected three weeks after charging the culture.

Cyclops can also be bred under the same conditions.

Rice. 48. Artemia

In the southern regions of the USSR, relatively large crustaceans are widespread in salt water reservoirs Artemia(Artemia salina), reaching 8-11 mm in length (Fig. 48). Adult crustaceans are usually not used as food, but only juvenile Artemia are used.

Many aquarists believe that Artemia larvae are the best food for fry of most fish species. On the shores of those reservoirs where many of these crustaceans are found, you can often find a whole roller of eggs carried out by the waves. These eggs are carefully collected, separated from debris and grains of sand and stored in a cool, dry place. Artemia eggs can sometimes be purchased at the store.

Artemia is best bred in low vessels, such as cuvettes. In this case, it is recommended to blow the water with air. To obtain juvenile brine shrimp, 1/4 teaspoon of eggs is placed in a 5% solution of table salt (1-1.5 tablespoons per liter of water). At a water temperature of 28-30°, the fry hatch after 20-24 hours, at 17-19° - after 40-50 hours. It is better to hatch brine shrimp at the same temperature at which they will be fed to the fish.

Artemia are convenient because juveniles can be obtained during the absence of food in natural reservoirs; in addition, juveniles of varying degrees of development and size can be used to feed fry of different ages. Unfortunately, the percentage of juveniles emerging from Artemia eggs is often insignificant; usually the yield does not exceed 10-30%. However, if the collected eggs are fanned with air and the less light ones are separated, then the yield from the heavier eggs reaches 80%. Eggs can be stored in a cool, dry place in glass jars for at least 10 years.

As a separator for winnowing heavy eggs from light eggs and from shells, it is convenient to use a vacuum cleaner turned on for blowing. In this case, you can place a wide pipe vertically and select its dimensions in such a way that unusable particles fly out and only heavy eggs are preserved. With this method, 4 liters are winnowed in 20 minutes.

When feeding fish with artemia, as well as other crustaceans, it is imperative to filter them through a sieve or net.

Both young and adult brine shrimp can be dried, thus preparing food suitable for many types of fish. Recently, newly hatched Artemia larvae have been frozen and stored in this form and used to feed fry. Since the larvae are dead and sink to the bottom, this type of food is especially suitable for feeding catfish and puntius (barbs), the fry of which pick up food from the ground.

Rice. 49. Bloodworm

Mosquito larvae. The greatest importance in feeding adult fish is bloodworm. Bloodworm is the common name for the larvae of a number of species of mosquitoes from the bell family Chironomidae sin Tendipedidae. In aquarium practice, large bloodworms are used to feed some fish - the larvae of the widespread mosquito (Chironomus plumosus), usually living in reservoirs with muddy soil (ponds, lakes, ditches). Much more often, small bloodworms are used, obtained from rivers heavily polluted by sewage. This includes the larvae of several species of mosquitoes from the same family (Fig. 49).

These mosquitoes lay their eggs, enclosed in a gelatinous, transparent substance, in water; Colorless or grayish larvae hatch from the eggs; after the first molt they become red. By secreting salivary glands, the larvae glue particles of silt into silty tubes in which they live, protruding only the head end. With this end, the bloodworm rummages through the mud, extracting various plant and animal remains. The bloodworm breathes with the help of thread-like gill appendages located at the rear end, as well as over the entire surface of the body; being in a calm state, he makes wave-like movements with his body, promoting the change of water around him. The bright red color of the animal depends on the color of the blood, rich in hemoglobin, which ensures the absorption of oxygen by the body.

Mature larvae pupate. When the time comes for hatching, the pupae rise to the surface of the water, their covers burst, and adult insects - mosquitoes - fly out.

In cities where fishing and fish farming are developed, you can buy bloodworms in pet stores and in stores of the “Fisherman-Sportsman” society; You can get it yourself. To do this, they usually use a scoop with a more or less long handle or a bucket on a rope and a sieve. Using a scoop or bucket, scoop up silt from the bottom of the reservoir and place it in small portions in a sieve; using rotational movements, they get rid of small particles of sludge, after which bloodworms and various large particles (soil, plants, shellfish) remain in the sieve. -The sieve is removed from the water for a while, then carefully lowered into the water again. At the same time, the bloodworm, slightly dried from the surface, floats up and is collected with a small net. After repeating this several times, a new portion of sludge is collected into the sieve for washing. When obtaining bloodworms, you need to know well the places of its highest concentrations at different times of the year; It is especially difficult to find it in the spring and the first half of summer.

The extracted bloodworms contain a significant admixture of various debris. To obtain clean bloodworms, they are placed in a sieve with holes large enough for it to fit through; The sieve is placed on a basin of water so that its bottom touches the water. The bloodworm crawls through the holes into the water and falls to the bottom of the basin, from where it is collected with a net, placed in a canvas rag and wrung out quite vigorously.

You can use different methods to store bloodworms. The simplest is storage in a damp canvas rag or burlap; in this case, the bloodworms should be placed in a layer of no more than 1 cm. Slightly damp bloodworms can be placed in a tightly covered low glass vessel; Petri dishes are especially good for this purpose. These methods make it possible to preserve bloodworms for 1-2 weeks.

Bloodworms are well preserved when kept in low vessels with water changed daily. Particularly favorable results are obtained when it is kept in sand and water. For this purpose, a net is made, through the cells of which bloodworms do not pass; using this net, the sand is washed and sorted so that its grains easily pass through the cells. Sand is placed in a layer of 1-2 cm in a low vessel, filled with water 1-2 mm above its level and bloodworms are placed. Live bloodworms quickly bury themselves in the sand. The weak and dead should be thrown out with water. Before feeding the fish, the sand is washed through a net, and the bloodworms remaining in it are used as food.

Rice. 50. Feeders for live and dry food

There are many other ways to preserve bloodworms. In all cases, it should be stored at low (+3-5°), but not negative temperatures. Only live, well-washed bloodworms can be eaten.

To feed fish with bloodworms, it is very good to use a foam feeder with a mesh bottom, through which the larvae gradually crawl into the water (Fig. 50).

In an aquarium with established biological “equilibrium,” uneaten remains of chopped bloodworms decompose faster than whole bloodworms.

Young and small fish can be fed with cut bloodworms. To do this, place a bunch of bloodworms on glass or paper folded several times (newspaper can be used) and cut them all together with scissors. The pulp obtained in this way is introduced into the water with several sharp movements of the scissors.

In shallow places in reservoirs, you can often catch a large number of transparent fish using a net. coretre- larvae of mosquitoes from the genus Chacborus (Corethra), reaching 10-12 mm in length (Fig. 51).

Rice. 51. Koretra

Koretra differs from bloodworms in that it does not burrow into the sand and lives in an aquarium for a long time. It is apparently less nutritious than bloodworms. Koretra can be used to feed most types of fish, periodically replacing it with bloodworms or other food; it feeds on a variety of animals, including large ones such as daphnia. This should be taken into account, since coretras in aquariums pose a danger to fry. Correts live for a long time in low, large vessels at low water temperatures. You can keep them in a damp chamber or rag, like bloodworms.

Rice. 52. Larva and pupa of the Culex mosquito

“Devils” often called the larvae of ordinary mosquitoes of the genus Culex (Fig. 52). In summer, they can be found in literally every puddle, where they swim upside down, touching the surface of the water with a breathing tube.

Usually the larvae are dark brown, almost black in color; they got their name from their characteristic structure and rapid “twitching” movements. The size of the larvae usually does not exceed 1 cm. The “devils” should be caught with sharp movements of the net, otherwise they quickly sink to the bottom.

Fish of many species willingly eat “devils”, preferring them to many other foods.

The larvae of many other mosquitoes, often found in large numbers in various small bodies of water, puddles, etc., are also used as food.

Hello to all readers of my blog!

Every aquarist can make a net for an aquarium. Perhaps someone will say that it’s easier to buy and they will be partly right, why bother with a needle, thread and wire when you can just buy, especially since it doesn’t cost much money.

In fact, how much easier and more convenient it will be for you when working with catching fish depends on the net, or rather, on its size. The idea for using a large net (a hoop with a diameter of 20 cm) did not come to me right away.

The large net that I now use for fish was originally made for catching coretras and daphnia, but the daily torment of catching fish for buyers gave me the idea to use a large net, because catching fish with an ordinary net takes a lot of time and patience.

If you don’t often catch fish and don’t go looking for bark and daphnia, you may not need a large net, but it still won’t hurt to make a spare net. Once at a pet store I was buying zebrafish and I felt sorry for the seller who took about 15 minutes to catch 4 fish. At this time I was thinking how I was missing a big net right now.

How to make a net with your own hands

To make a large net you will need: a piece of rigid wire approximately 120 cm, preferably (not necessarily) made of stainless steel with a diameter of 4-5 mm. Not very dense fabric organza, chiffon, nylon, nylon, voile No. 7-76.

The shape of the hoop, square or round, doesn’t matter, I make it square with each side measuring 20 cm, and twist the remaining tails of the wires, they will serve as a handle. If the handle seems short, you can lengthen it.

Next we make the pattern and the bag. Bags for nets can be different, for example, simply from two halves of fabric, the pattern of which has a parabolic shape. Or a cross-shaped pattern, which is considered the most profitable of all possible options. The bag turns out to be rectangular with a flat bottom and safe for fish when catching them.

Honestly, I used different nets and didn’t hurt a single fish, and it seems to me that this depends on the aquarist himself, and not on the shape of the bag. We carefully measure the pattern, taking into account the fact that the length of the bag should be about half the diameter of the hoop (in my case 30 cm), we also take into account the part of the wrapped material on the lining of the darling.

To improve the quality of the net, it is advisable to strengthen the areas where the shell is sheathed by sheathing it with additional material. To catch daphnia or coretra, we attach the net to a pole by wrapping the handle of the net with wire or rope.

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Preparation of dried daphnia | AquaDomik

At the beginning of summer, when the ponds inhabited by daphnia are not yet overgrown with duckweed, hornwort and other aquatic plants, you can store dried daphnia for the winter.

You need to dry daphnia on a clear, hot day in the morning, having previously prepared several wooden frames measuring about 80*60 cm with ordinary gauze stretched over them, taking with you a bucket and some kind of mug or just a tin can, squeezed on one side so that When pouring daphnia, the widest possible stream of water was obtained. Having 10 frames with you, on a good hot day you can prepare up to 2 kg of dry daphnia. A net for catching daphnia should be made of rare material, perhaps from ordinary gauze, with a handle longer than an ordinary net. Daphnia should not be squeezed out in a net; it is better to let the water drain and then dump it into a bucket. When half the bucket is full, you need to dilute the daphnia with water and pour it along with the water over a pre-wetted frame, holding it at an angle. Pour should be made by making quick movements from top to bottom with the hand holding the mug so that the daphnia is applied to the gauze in an even layer. When the entire frame is covered with daphnia, it is placed against the sun, placing a support under one edge so that the sun's rays fall perpendicularly on the frame. If the daphnia is spread evenly and not in a very thick layer, then its complete drying in good sunlight is achieved within two hours. You should remove the daphnia from the gauze using a knife, placing the frame with the daphnia on its edge. Daphnia is scraped off in the form of sticky pieces, which easily crumble when further sifted through a coarse sieve. Sifting dry daphnia is necessary in order to separate dried insects and any debris caught along with the crustaceans. This procedure, of course, can be done not at the pond, but at home. At the pond, it is enough to limit yourself to removing daphnia from the nets. You can simply dry daphnia on gauze or some other material laid out on the ground. The disadvantage of this method is that it can only be used in calm weather. At the slightest wind, the daphnia will be blown away, while with the first method, the wind, on the contrary, helps drying, significantly speeding it up.

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Chapter 3. FEEDING FISH

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The first live food for newly hatched fry of spawning fish are ciliates, bred as a pure culture or together with the smallest crustaceans caught in ponds in the form of live “dust”. To the naked eye they appear to be just small moving dots, but with a little magnification and a good magnifying glass you can see that they are living creatures. Newborn fry see them well and eat them in countless quantities.

If such food is given evenly, so that it is in the aquarium continuously, then the fry of all spawning fish grow quickly and soon reach a size that allows them to absorb larger food - small cyclops or daphnia.

Such tiny live food can be easily obtained in any standing body of water; it is separated from larger feed by filtering through a net made of awning or nylon stocking.

Spring is the season when water bodies are richest in such “dust”, so at this time of year it is easiest to feed aquarium fish fry. However, you can have such tiny food at any time of the year by maintaining an artificial culture of it at home. It is most advisable to use ciliates for this purpose, since maintaining a culture of crustaceans is difficult and they quickly grow beyond the size of the “dust”. Fish most willingly take a certain type of ciliate - the slipper, or paramecium (Paramaecium caudatum) (Fig. 18).

Rice. 18. Ciliates (slipper).

You can get a slipper in any standing body of water. It is abundantly populated by small, stagnant ponds with fallen leaves, small peat bogs, and country pits with rotting organic matter.

Such bodies of water often emit a characteristic hydrogen sulfide odor and are usually teeming with many different ciliates, especially near the shore. If you collect water from such a body of water in a bottle or test tube, you can view its population through a magnifying glass. Ciliates differ from crustaceans by their smooth movements and rounded outlines. In most crustaceans, movements are spasmodic, and under a magnifying glass their jointed limbs are already quite visible.

The shoe is a medium-sized ciliate (0.25-0.3 mm) and has a slender spindle-shaped body, shaped really like the sole of a shoe. The movement of the paramecium is very fast; during forward movement, the animal rotates around its axis.

The enemies of protozoa, including slippers, are all small animals that feed on them - predatory ciliates, rotifers, daphnia, cyclops, insects and their larvae. Therefore, and also taking into account the preference for using paramecia for food, you need to choose a crop that contains only ciliates - most of them are slippers. It is even better to create a pure culture, which is done as follows. You need to pour some water into the watch glass from the natural culture in which the shoes were seen.

The population located in the glass should be viewed under a dissecting loupe. If there are many ciliates of various types in the glass, then the culture needs to be diluted with water so that the ciliates are distributed less frequently, then individual paramecium can be caught under a magnifying glass, which is done using a pipette with a thinly drawn end of a glass tube. One to two dozen paramecia caught are placed in prepared jars with hay infusion (boil 10 g of hay in 1 liter of water for 1 hour). The slippers multiply quickly, division occurs at least once a day, and after a week, under favorable conditions, they can be seen even with the naked eye in the form of a mass of whitish moving points in the upper part of the vessel. The water in the vessel becomes cloudy and gives off a putrid smell, but this should not bother the amateur. The vessel with the culture should not be placed in direct sunlight; it can even be placed in a dark place. You should not be afraid of temperature drops even to 10° C and below. But ciliates reproduce well only at room temperature 18-22°C.

To maintain the culture, it is necessary to add boiled milk to the water no more than twice a month, based on the proportion of 5 drops per 100 cm3 of water.

It is better to feed the fry with filtered ciliates. To do this, filter or school blotting paper is inserted into the funnel, which retains the ciliates. After filtering, the paper with the ciliates settled on it is rinsed in places where the fry accumulate. You can simply pour part of the liquid with the culture of ciliates into an aquarium with fry, but this will spoil the water in the aquarium a little.

In extreme cases, you can replace live “dust” or an artificial culture of ciliates when growing fry of spawning fish with egg yolk. A small piece of the yolk of a hard-boiled egg is ground in a spoonful of water taken from the aquarium. In this form, the yolk should be given after 2-3 hours, a few drops at a time, to the places where the fry gather, where they quickly grab it.

The best live food for fry of spawning fish that have grown somewhat on ciliates or living “dust” or just hatched viviparous fish are lower crustaceans - cyclops and daphnia.

Starting in April, as soon as the sun really warms up and the water temperature in the ponds rises above +8°C, a cyclops (Cyclops) appears, belonging to the order of copepods (Copepoda) of the subclass of lower crayfish (Entomostaca). The body of the Cyclops is noticeably divided into a cephalothorax and abdomen. The body length ranges from 1 to 4 mm depending on its type and age. On the head there is an unpaired eye, which gave rise to the name of the crustacean. The organs of movement and soaring are antennae, lined with short hairs and bristles. By simultaneously hitting the antennae and rowing legs, the Cyclops jumps forward. Having jumped, the crustacean spreads its antenna wide, like a parachute, and, as if floating, slowly descends (Fig. 19).

Rice. 19. Cyclops.

Cyclops' food consists of microscopic algae and other small organisms. Cyclops, like all copepods, breathes over the entire surface of the body.

The eggs, when released from the female's oviducts, form two elongated egg sacs, which are located on the sides of the end of the body until the larvae hatch from them. The larva swims animatedly in the water, grows and moults. During its transformations, the Cyclops goes through five unsegmented and six segmented stages, the last of which corresponds to an adult sexually mature animal.

The same order of copepods also includes a number of Diaptomus, distinguished by their elliptical body shape and longer antennae. Diaptomus is less readily eaten by fish due to the hardness of its shell.

Cyclops is good to feed all fish of relatively small size, but for larger fish in the summer, the best live food is the daphnia crustacean (Daphnia pulex. Subclass Entomostaca, order Phyllopoda - phyllopods, suborder Cladocera - cladocerans) (Fig. 20).

Rice. 20. Daphnia.

The body length of daphnia reaches 5 mm, its body is enclosed in a chitinous sheath. The head of the daphnia, not covered with a shell, has a large compound eye, next to which there is a small simple eye. The second pair of antennae, each with two branches, represents the crustacean’s powerful rowing organ. During daphnia's jumps, followed by a smooth descent - soaring, fatigue is not noticeable; it never sinks to the bottom: this is facilitated by the small specific gravity of the crustacean due to the abundant fat, visible through the transparent body of the crustacean in the form of brightly colored drops.

In the warm season, daphnia reproduces; females lay unfertilized eggs in the embryonic sac, which quickly develop and after 3-4 days, fully formed small daphnia, ready to emerge, can already be seen through the walls of the case. Juvenile daphnia grow quickly and, after going through three molts, reach sexual maturity 8-10 days after leaving the egg. If we take into account that the female gives birth to offspring every 3-4 days in the amount of about 80 individuals, each of which itself gives birth to offspring after 12-14 days, then it becomes clear where the masses of daphnia populating our water bodies come from.

The best daphnia for fish food is red. It appears in almost all dirty standing waters in the spring, at first very fine in the form of dust, and with the onset of hot days it becomes larger and larger and in such quantities that it can be seen hanging along the shore in whole clouds of rusty color.

Only large fish can be fed with large live daphnia. To catch cyclops and daphnia you need a net. A ring for a net with a diameter of 250-300 mm must be bent from a piece of wire 3-5 mm thick, leaving two ends bent, which should be attached to a stick up to 2 m long. A bag 50-60 cm deep, shaped like a cone, rounded at end. The bag should be made of a material that easily allows water to pass through, for example, awning to catch “dust.” The lower part of the net or the entire net is made of denser material.

When fishing in the summer, you should keep in mind that there is more food on the side from which the wind blows, but in calm weather the food is kept in the same quantity throughout the pond.

In a musty reservoir, daphnia stays at the surface of the water closer to the shore; in relatively clean water, it sinks into the lower, cooler, oxygen-rich layers of water.

You should not drive the net for a long time, waiting until there is more food in the net; it is better to remove the net more often and throw cyclops or daphnia into the can, since when driving the net for a long time, part of the food suffocates. For the same reason, you should not use much effort; it is better to move the net calmly.

In both winter and summer, you should never feed fish with freshly caught cyclops. First of all, you need to strain the food through a thin mesh or sieve into a basin so that water insects, larvae and debris do not get into the food. Food poured into a basin in winter should stand in the room until the temperature of the water in the basin is equal to the temperature of the water in the aquarium. Only after this can you feed the fish. Otherwise, due to a sharp change in temperature, almost the entire Cyclops dies, settles to the bottom and causes water spoilage.

To keep the food alive for several days, it should be poured into a flat container so that the water level is no higher than 3-4 cm, or, if left in a basin, it should be blown with air. Dead cyclops and daphnia settle to the bottom; they should be periodically removed using a blower or by pouring the top layer of water with live crustaceans into another vessel and discarding the remaining sediment.

Since live daphnia is a good food for all fish, dried daphnia is one of the best foods after live food. Therefore, at the beginning of summer, when ponds inhabited by daphnia are not yet overgrown with duckweed, hornwort and other aquatic plants, you can store dried daphnia for the winter.

You need to dry daphnia on a clear, hot day in the morning, having previously prepared several wooden frames measuring about 80X60 cm with ordinary gauze stretched over them, taking with you a bucket and some kind of mug or just a tin can, squeezed on one side so that when spilled Daphnia received the widest possible stream of water. Having 10 frames with you, on a good hot day you can dry up to 2 kg of dry daphnia.

A net for catching daphnia should be made of rare material, perhaps from ordinary gauze, with a handle longer than an ordinary net. Daphnia should not be squeezed out in a net; it is better to let the water drain and then dump it into a bucket. When half the bucket is full, you need to dilute the daphnia with water and pour it along with the water over a pre-wetted frame, holding it at an angle. Pour should be made by making quick movements from top to bottom with the hand holding the mug so that the daphnia is applied to the gauze in an even layer. When the entire frame is covered with daphnia, it is placed against the sun, placing a support under one edge so that the sun's rays fall perpendicularly on the frame.

If the daphnia is spread evenly and not in a very thick layer, then its complete drying in good sunlight is achieved within two hours.

You should remove the daphnia from the gauze using a knife, placing the frame with the daphnia on its edge. Daphnia is scraped off in the form of sticky pieces, which easily crumble when further sifted through a coarse sieve. Sifting dry daphnia is necessary in order to separate dried insects and any debris caught along with the crustaceans.

This procedure, of course, can be done not at the pond, but at home. At the pond, it is enough to limit yourself to removing daphnia from the nets.

You can simply dry daphnia on gauze or some other material laid out on the ground. The disadvantage of this method is that it can only be used in calm weather. With the slightest wind, the daphnia will be blown away and the work may be in vain, while with the first method, the wind, on the contrary, helps drying, significantly speeding it up.

Dried daphnia should be stored in tightly closed metal or wooden boxes. If the daphnia is not completely dried, mold may appear during storage and destroy the entire daphnia. Dried daphnia should not be stored in a bag, as it can harbor moths, the larvae of which turn the daphnia into dust, making it completely unsuitable for food.

In winter, you can also catch live food in almost all ponds, but it is much more difficult. If there is a pond with a permanent ice hole, then cyclops can be caught in such a pond throughout the winter until February. From February or the end of January, very few of them are made and in the end they completely disappear, appearing only when the ice begins to melt and ice-free water appears near the shore; At this time, you can start catching cyclops from the shore.

In winter, live food is obtained in an ice hole, which should be cut with a crowbar, the end of which is flattened in the form of a hatchet. First, you need to cut a furrow along the contour of an oval shape (the desired size) for two-thirds of the entire circumference, right through to the water. Then, with several blows on the uncut part of the circle, break off the ice floe and push it under the ice. After this, all that remains is to clear the water of small pieces of ice floating in the water. The vessel intended for cyclops should be carried in a cotton case in winter so that the water does not freeze.

If you place some cyclops or daphnia caught from a pond in a glass vessel and look closely, then among the caught crustaceans you can distinguish the completely transparent larvae of the corethra mosquito (Chaoborus crystallinus - Corethra plumicornis) 10-12 mm long, which are revealed by their black eyes and tracheal bladders. The coretra larva feeds on plankton. Standing motionless in the water, she tracks down cyclops and daphnia, pounces on them with a sharp throw, grabbing her prey with the trapping apparatus of the mouthparts (Fig. 21).

Rice. 21. Development of the coretra mosquito.

The larva is dangerous for fry of spawning fish, especially small ones, such as lalius. At the same time, the coretra is a good food for all fish: it lives in an aquarium for a very long time, does not bury itself in the sand like bloodworms, stays among thickets of plants, and the fish have the opportunity to hunt for it all the time. Koretra can be stored for a long time in the same way as bloodworms, in a damp cloth in a cool place, but it is better to keep it in periodically refreshed water.

An excellent live food for all fish without exception, not only adults, but also for grown-up fry of many spawning fish and all viviparous fish, is the well-known red larva of the mosquito (Tendipes - Chironomus plumosus) - bloodworm (Fig. 22).

Rice. 22. Bloodworm.

The red color of the bloodworm larva is given by the hemoglobin contained in its blood. Bloodworms live in silt and, rummaging in it, find abundant food. The larvae weave a web around their passages and, clinging to the walls of this peculiar tube with the hooks of their legs, can protrude from it or hide in the depths of the silt. In warm weather and an abundance of food, the larvae grow quickly and 15 days after laying eggs reach a length of up to 15 mm. The larva molts three times and pupates after maturation. The pupa floats to the surface of the water just before the mosquito flies out. This mosquito does not bite, it differs from the ordinary one in its large size and the manner of twitching its front legs extended forward, for which it received the name “twitch mosquito.”

Large bloodworms the thickness of a match are only suitable for feeding large fish (veiltails, telescopes, large viviparous fish and all predators). For other fish, you should take small bloodworms. It is important that the bloodworms are fresh and alive. This can be seen if you move a bunch of bloodworms with your finger, the fresh bloodworms begin to move vigorously. Stale bloodworms stick together and have a dark color. Eating such bloodworms is risky; it can cause illness and sometimes death of fish.

You can catch bloodworms yourself, but to do this you need to know the places where there are a lot of them, although they are found in almost all dirty reservoirs, both with standing water and with quietly flowing water. To catch bloodworms, you need to have a bucket with a rope 8-10 m long and a sieve with a fine mesh. The bucket tied to the rope is thrown further away. When it sinks, it is pulled to the shore, dragged along the bottom in order to scoop up the bottom mud, in which the bloodworm lives. When the bucket is pulled ashore, a little dirt is collected from it into a sieve and washed in water, making rotational movements until all the dirt comes off and only bloodworms and debris that do not fit into the holes of the mesh remain in the sieve.

The entire contents of the sieve, with the exception of large debris, which can be removed immediately, are dumped into a rag made of rough canvas prepared for this purpose.

In winter, bloodworms are obtained in the same way from an ice hole.

At home, the bloodworms are laid out in a wide sieve with large holes, which is placed over a basin, into which water is poured so that the bottom of the sieve lightly touches the water. Having felt the water, the bloodworm immediately begins to crawl through the sieve and within a short time, depending on the total number of bloodworms, it is all in the water. The garbage is thrown away, and the bloodworms are laid out on a dry rag, and when all the water has drained from it, the entire procedure for preparing the bloodworms should be considered complete.

Since the bloodworm tends to quickly burrow into the sand, it is best to give it by placing it in a special floating bloodworm, through the holes in the bottom of which the bloodworm crawls gradually and the fish grab it, not giving it the opportunity to burrow into the sand. Some fish pull it out of the moth as soon as it starts to crawl out. This method is also good because only live bloodworms will pass through the holes, and the dead ones remain in the bloodworm and can be easily removed. Small fish and fry can be fed with cut bloodworms. Having placed a little bloodworm on a small piece of glass, holding it slightly inclined so that the blood drains, you need to quickly cut the bloodworm with scissors until it turns into a bloody pulp. To make it easier for fish to find cut bloodworms and eat them without leaving a trace, they need to be thrown into the aquarium in a lump.

For storage, bloodworms should be placed in a thin layer of 1 cm in a dry, thick canvas rag, folded in half, which should be wrapped in a burlap rag, soaked in cold water and wrung out well. In this way, bloodworms can be preserved for 7-10 days, of course, only in a cool place. In winter, you can use bloodworms completely frozen, but you should not give them right away, so as not to catch a cold, but first warm them up or simply pour them over with hot water. All fish eat such bloodworms with pleasure, although it cannot be considered complete.

If in the summer it is possible to get a large amount of bloodworms, it can be dried. Dried bloodworms are a good food, but only if the bloodworms are dried fresh and not in the sun (during prolonged drying, some of the bloodworms may deteriorate), but in an oven, so that drying occurs quickly, but so that the bloodworms do not burn. Should be stored in tightly closed boxes.

For large fish, dried bloodworms should first be scalded with boiling water before giving food and given in this form to the aquarium; small fish can be fed, like dry daphnia, by first rubbing the bloodworms between your fingers.

Small earthworms are good food for all large fish. They can be given whole, but it is better to cut them into small pieces with scissors and then give the amount that the fish can eat at one time.

You can get earthworms in the summer in damp places, store them in a box with garden soil, occasionally moistening it, in a cool place. In this way, you can preserve worms all winter in any quantity.

Among some hobbyists, another type of live food is common, bred as an indoor culture. These are oligochaete worms belonging to the genus Enchytraeus, yellowish-white in color, up to 1.5 cm in size, which are bred in boxes with moist black soil at room temperature. They are fed with pieces of white bread soaked in milk, sour porridge, mashed potatoes, etc., which are buried in the ground (Fig. 23).

Rice. 23. Enchytrea (a longitudinal section of the body is given at the front).

A small pinch of these oligochaetes, finding themselves in favorable conditions, multiply so quickly that after 3-4 weeks you can begin to take them for food. To do this, you should dig out the place where the feeding was placed, and there will be whole tubers of worms, which you can take either with tweezers or just with your fingers and give to the fish. All fish eat them willingly. To separate the enchitrae from the ground, you can fill them with water - the worms will quickly crawl to the surface, from where they can be easily collected. Like bloodworms, enchitraea burrow into the ground, so they should be fed according to the number of fish. This food is interesting because it reproduces equally well all year round and is easy to preserve and breed.

In terms of nutritional value, only raw meat without fatty layers can be compared with the live and dried food described above, which, in the absence of live food, is good to feed almost all adult fish, for which it is scraped with a knife and given to the fish in this form. In extreme cases, fresh meat can be replaced with dried meat, for which it is passed through a meat grinder and kept in a hot oven until completely dry. Before giving it to the fish, scald a portion of dry meat with boiling water. Small fish can be fed with the same dry meat, previously crushed in a mortar and given as dry daphnia.

In the absence of other food, you can feed almost all fish (except predators) with food made from cereals: semolina, millet, buckwheat; This food is well eaten by all types of carp fish, as well as labyrinth fish, but you should resort to it only as a last resort. A steep porridge is cooked from the cereal, then it should be washed in cold water until all the mucus is separated, then strain through a sieve and stored in a cold place. Buckwheat should be raw, not fried. Buckwheat food, since it is larger in size, should only be fed to large fish, such as veiltails; Semolina and millet cereals can be fed to livebearers and other small fish.

With all types of non-living food (egg yolk, dried daphnia, cut, dried and frozen bloodworms, raw and dried meat, porridge, etc.) you need to be very careful: the remains of food quickly decompose and spoil the water. This food should be given in such quantity that it is quickly disassembled and eaten by the fish without any residue.

ptivpr.narod.ru

A net for obtaining food (live dust).

All aquarists know that raising young fish without live food is not very promising. You can, of course, try to make do with artificial food, but not all types of fish will feed on it. This is especially true for starter feed. Live dust is a universal food for most species. It may include nauplii of daphnia and cyclops, rotifers, ciliates and representatives of phytoplankton. But in order to obtain the living dust necessary for the fry, a special plankton net is needed.

You can try to buy a net from experienced aquarists. But it’s better to do it yourself. There are many designs of nets. Although in general it all comes down to a stick (handle), a hoop and a plankton net. For me personally, it turned out to be difficult to get hold of a plankton net. It must be made of a special fabric called “mill gas”. It is used in flour mills to sift flour. You can search for it on the Internet. Or you can go to fabric stores and choose a suitable analogue. The fabric should not stretch and should have as few cells between the threads as possible.

At different times, handles for nets were made from different materials. Starting from bamboo sticks, which were made detachable and connected to each other using tubes, like in a bamboo fishing rod. Next were structures made of duralumin and plastic tubes. But perhaps the most successful is the handle made from a plastic telescopic rod.

The ring for the mesh is best made from wire with a diameter of 4 - 6 mm. The diameter of the ring itself can vary from 20 to 60 cm. The wire must be elastic - steel or steel, preferably coated with zinc, anodized or tinned.

The plankton network is cut out in such a way as to form a cone. The net is sewn to the ring either directly, or you can cover the ring with thick fabric and sew a gas cone to it. The second option is more reliable - the gas will not rub against the metal hoop.

And now everything is in order. First of all, we decide what diameter the hoop of our net will be. It is better to take something in between 30 - 40 cm. First you need to bend a ring of the selected diameter, and then bend the wire at an angle of 90 degrees to attach it to the handle. In order to make the hoop even, you can bend the wire around an object, such as a bucket or tank. It is better to make the ends of the fasteners of different lengths.

For the handle we take a telescopic rod. Its length should be 5 - 6 meters. The last knee (the thinnest) needs to be removed. To do this, you need to remove the plug at the bottom, after which you can pull out the extra link. On some rods the plug is simply screwed on, but sometimes to remove it you need to immerse the bottom of the rod in boiling water for a few minutes and then remove it. Once the rod tip is removed, you can put everything back together as it was.

The next step is to attach the hoop to the handle. To do this, we insert the long part of the wire fastening into the second elbow, which has now become the first. The second part of the wire fastening remains outside. Now we slightly wedge the knee with the wire using a wooden wedge. And then we wrap the outer part of the fastening with nylon thread. After winding, you can coat the top of the thread with waterproof glue, after securing the end with a reliable knot.

Now we need to sew a cone of mill gas onto the prepared base of our plankton net. It is better to prepare it first by stitching it on a sewing machine. Threads should be taken from synthetic materials, then they will not deteriorate from dampness.

The good thing about the finished design is that it folds and unfolds easily. A net of this design is convenient to transport in transport. The length of the telescopic rod allows you to catch food in hard-to-reach places. The rod's handle is springy and does not allow sudden movements in the water, which has a positive effect on the amount of live dust caught.

www.aqvasamodelki.ru

You can watch the fish for hours.

We previously wrote about how to breed daphnia.
And this note talks about how to catch them correctly.

When fishing in natural reservoirs for daphnia, cyclops and “live dust”, the following rules must be observed:
1. When catching food, you cannot move the net in the water for a long time; you must remove the net more often and transfer the prey to the can, otherwise part of the food will die in the net - the crustaceans will simply suffocate.
2. Live food should be transported (transported) in large vessels if possible. You cannot put a lot of live food in a can (jar) - this will lead to the fact that part of the food will die on the way.
3. You should never feed live food to fish by scooping it with a net from a can (jar) in which it was just brought home along with water from the reservoir. It’s even worse to pour this food out of the can directly with water and pour it directly into the aquarium.
Remember! Along with the food caught directly from the can with a net, various aquatic animals that are dangerous to fish can get into the net and then into the aquarium, as well as rubbish that can carry fish disease carriers and various microorganisms that cause diseases. Even more of these harmful animals, carriers and pathogens of fish diseases will enter the aquarium along with water from the reservoir.
When feeding fish with live daphnia, Cyclops and “live dust”, the following rules must be observed:
1. First of all, the food brought home must be filtered through a thin mesh or sieve - thin gauze may be suitable for this purpose. Anything that remains on this first filter is not suitable for feed. Living dust, cyclops, and daphnia must pass through such a sieve.
2. The food strained in this way, together with the water in which it was brought from the reservoir, should be kept at home in a basin until the temperature of the water in the basin reaches room temperature. Otherwise, live food entering the aquarium will die from a sudden change in temperature. Cyclops are especially sensitive to sudden changes in temperature. Only after the water in the basin has reached room temperature can the feed begin to be sorted.
3. To separate their juveniles and larvae, as well as “living dust” from large daphnia and cyclops, use nets made of very dense fabric, which allows only the smallest organisms to pass through, but retains daphnia, cyclops and their juveniles. The crustaceans remaining in the net are placed in a basin with fresh, settled water at room temperature, and only from here, from clean water, can food be taken to feed the fish. Using a net with even denser fabric, they catch the “living dust” and also place it in a basin with fresh, settled water. The water brought from the reservoir is now poured out. Having several nets covered with material of different densities, all the food obtained can be sorted into large, smaller, small, the smallest, “live dust”.
4. Strained food, placed in fresh, settled water, should be stored at home in a basin or in a bathtub, selected in such a way that the water in the dish is poured in a layer of only 3-4 cm, otherwise the food will quickly die. If there is no such a wide, flat vessel, then the vessel with the food must be purged with air (you will learn later how to arrange the purge).
5. Constantly, part of the food you catch will die and settle to the bottom. Such dead daphnia and cyclops that have settled to the bottom must be periodically removed from the basin or bath so that they do not spoil the water. They do it this way: use a stick to swirl water in a basin. The water moving in a circle carries along the dead food and collects it in the center in a low hill. This slide, after the water has calmed down, can be simply assembled with a hose or a mud scraper, which is used to remove dirt from the bottom of the aquarium.
Live food is not stored for a long time, and it has to be obtained all the time. Unfortunately, in winter, daphnia almost disappears, and it is more difficult to wash away the “living dust.” Therefore, in winter, fry are often fed with ciliates and rotifers bred at home, and larger fish, instead of daphnia and cyclops, are given nematode worms, small bloodworms, and small tubifex.

EASIER - BUY, BETTER - MAKE

I.VANYUSHIN
Mytishchi, Moscow region.

How many nets should an aquarist have, what should they be and where to get them? It all depends on how “advanced” the amateur is in his hobby. If the owner of a home pond is limited to the role of observer, then one net is enough; it will be in demand only in cases (hopefully rare) when it is necessary to remove a dead fish. The easiest way to buy such a hunting tool is at the first pet store you come across. True, a factory-made product will not always satisfy the buyer in appearance, ease of use and other ergonomic parameters. But in this case, this can be neglected, given that most of the time the net will gather dust in the far corner of the aquarium farm.

Another thing is an aquarist-naturalist, a breeder. In everyday practice, he is often faced with the need to catch fish, for example for breeding, transportation, quarantine or treatment. Many people prefer to feed their pets plankton from the nearest pond. But you need to catch it with something, wash it in something and sort it... You can’t do it with just a net, and the requirements for products of this type are stricter. They should be as comfortable as possible, durable enough, and not injure fish and invertebrates.

Photo The most convenient option for attaching a catch bag
to the handle of the net

To make a fishing net bag, synthetic fabric should be used. Often nets are made from nylon stockings, but this is not the best option. Its disadvantages are elasticity (the size of the cells changes under load) and low mechanical strength. The best fabric is the so-called mill gas, or “sieve fabric”. It has a unique marking from No. 7 to No. 76 (OST 17-46-71). The number means the number of holes per linear centimeter, that is, the larger the number, the smaller the holes. In mill gas No. 7 the holes have a size of 1.093x1.093 mm, and in No. 76 - 0.082x0.082 mm. Using this OST, you can, for example, armed with a magnifying glass, count the holes and determine the number of the unknown nylon fabric that came to you.
Selecting the appropriate fabric depends on the size of plankton required. The pattern looks like a more or less wide sector of a circle, the radius of which will be the length of the cone of the finished net (50-70 cm). The width of the sector depends on the circumference of the bow (ring) of the net, taking into account the addition to the connecting seam. If there is a shortage of fine gas, the top of the net can also be made from a larger one - in the form of a wide strip. Decide for yourself what will be decisive: the width of the available fabric or the convenient diameter of the net.

It is undesirable to leave a sharp corner at the bottom when stitching: it is inconvenient to work with. In the literature on aquarium keeping, a net is always depicted, the top of which covers a bow (ring). However, practice shows that a more convenient option is when free carriers (straps) from the same nylon (with a diameter of 4-5 centimeters) are sewn to the top of the net. at a distance of 5-6 centimeters from each other around the entire circumference (Fig. 1). The handle is easily threaded through these loops, and it is more comfortable to work with such a net. In addition, this option allows the use of a folding (detachable) bail, which is sometimes used for the convenience of transporting large nets.
Small nets are required for sorting plankton and for catching fish. The bags for them are made using a “cross-shaped” pattern, which is advantageous. which results in a flat bottom. In such a net, the risk of damage to strained crustaceans or caught fish is minimal. From a pattern with right angles, a rectangular bag is obtained, and if the sides are trapezoidal, a pyramidal one is obtained. First make a “model” of a paper net to see if the proportions you choose will be comfortable.

Of course, a net made from two halves of fabric, the pattern of which has a parabolic shape, is also quite suitable. It is also advisable to use nylon materials here - they last longer.
To catch fish, you need soft fabric with fairly large cells. Nylon tulle will do. If you have to catch fry with this net, be sure that the width of the cell is small enough and will not allow the fry to get their heads stuck in it. It is unlikely that we will be able to get him alive. Prepare several nets for different purposes.

Photo of a factory net bag with a narrow bottom

Sometimes authors talk about the color of the fabric. I have nets white, green and black. Fish seem to be less wary of the color green. And the easiest way is for them to fall into a transparent trap. At one time, at the World of Aquarium exhibition, a 600-liter aquarium housed a rich collection of botia and acanthophthalmus. These tropical loaches, as you know, are not easy to catch even in a small aquarium. I once took a plastic bottle.

I cut off the wide part of her throat and inserted it into the “glass” with the reverse side. I put a bunch of tubifex inside and lowered the “device” to the bottom. About twenty minutes later the bottle was literally filled with fighters, and they were no longer smart enough to get out through the neck into freedom.
For the nets with which you will sort the harvested plankton, you must use the same mill gas of the appropriate number. For initial cleaning, the prey can be passed through a coarse sieve (even more convenient if it is made of metal threads) with a mesh size of 2x2 mm or even larger if you are catching large daphnia. Such a sieve will retain the inevitable debris, water beetles and bugs (smooth fish, swimmers, etc.), as well as the larvae of various insects (if there are large fish in the aquariums, the screenings can be fed to them).

By alternately passing plankton through fabric of different densities, you can sort the catch into batches of food suitable for pets of different ages. The smallest mesh net should only allow cyclops, diaptomus and daphnia nauplii to pass through. It is appropriate to note that even fabric No. 76 will not retain ciliates, since they are able to squeeze through smaller holes.

Photo cutting methods

And now general recommendations for production. Draw the pattern of the net on paper, cut it out, and then, placing the model on nylon fabric, outline it with a felt-tip pen. Add seam allowance. Carefully cut the nylon pattern with a heated knife to melt the edges. The seams on a fishing net can be sewn manually or using an overlocker on a sewing machine, and also with synthetic thread (for example, thin fishing line).
Plankton sorting nets are a little more difficult to handle. There are no problems with coarse mesh fabric, but it is better to glue the seams of the net for screening out the “dust” part of the plankton with a thin layer of silicone sealant, since

To form an adhesive seam (or level a patch), cover it with PVC film (from packaging bags) and press lightly and leave in this position for 10-15 hours, subsequently the film will easily separate from the hardened sealant. Again, I suggest not wrapping the net fabric around the handle. Simply sew the edge of the fabric close to the bow, covering it with thread. It turns out very neat.
And finally, the last net, which I recommend having on the farm. It is needed only by those who breed small aquarium fish and periodically have to catch tiny fry (for example, for transplantation into another nursery). The nose of a non-elastic nylon stocking is sewn to a bow with a diameter of 6-7 centimeters. The sagging of the fabric should be no more than 1-1.5 cm, and it itself should not fold. This creates something like a soft spoon. The jumping ability of fish at this tender age is negligible and the transfer of fry in such a net occurs without injury.

Aquarium Magazine 2003 No. 6