Zebrafish: varieties, selection, care, reproduction

Danio is the most popular variety of aquarium fish, notable not only for its spectacular appearance, but also for its amazing unpretentiousness. Frolicking with a bright and friendly flock in the aquarium, they revitalize the home atmosphere, bring beauty and harmony to it.

Danio is a genus of small ray-finned fish belonging to the cyprinid family. The initial habitat of these charming creatures are freshwater areas of Southeast Asia. The average size of adults varies between 4-4.5 centimeters. Some specimens are capable of reaching 6–9 centimeters in length. The size, body color, color and shape of the fins depend on the type of fish.

Many varieties of zebrafish are widespread in the aquarium. They are not too demanding to care, easily breed in captivity. To date, scientists have developed a number of interesting breeding forms with atypical colors, sizes and shapes of fins for fish of this genus. One of the breeding forms of zebrafish - transgenic (GloFish) makes a strong impression.

One of the brightest virtues of aquarium zebrafish is their peace-loving and non-conflict nature. They are energetic, very mobile, cheerful. The other inhabitants of the aquarium zebrafish are neutral, without showing aggression.Like many other small representatives of the aquarium fauna, the life span of zebrafish is not too long. The average life expectancy in small individuals is about 3 years, in large individuals (9-10 centimeters long) - about 6 years.

In aquariums, a wide variety of these charming fish are popular. They all differ from each other in interesting and original colors, sizes, body shape and fins.

• Pearl Danios - A variety of beautiful freshwater fish, the natural habitat of which are the waters of the Malay Peninsula and the island of Sumatra. The color of their body depends on the region of origin. This type of zebrafish has several basic color forms. The most common color is an iridescent bluish, with an orange-red stripe running along the body and enhancing the color of the caudal fin. The average size of adults is 4.5-5 centimeters.

• Firefly (or Hopra) - A variety of zebrafish, considered the smallest representatives of a kind. The average size of their body rarely exceeds 2-3 centimeters. Body color - gray-olive with a metallic tint. A bright orange-red stripe runs along the trunk in the upper part under the dorsal fin. Across the body along the midline are dark gray stripes. The fins are translucent. The dorsal fin is decorated with a longitudinal orange-yellow stripe.

• Dangila - A very beautiful variety of zebrafish. In their natural habitat, they are able to grow up to 15 centimeters in length. In captivity, these unusual fish usually reach 8–9 centimeters. Their characteristic feature is a pair of elongated antennae, going down from the mouth gap. The color of the fish varies from pinkish-brown to silver-blue with a metallic tint. The most common color option is silver or pinkish-olive. The fins are translucent and most often a light shade. Closer to the gills, the zebrafish dangil usually has a small, rounded mark of dark color.

• Kerry - a variety of zebrafish that lives in freshwater bodies of water in the southern part of the Malay Peninsula, as well as in streams and rivers of the nearby islands of Phuket and Koh Lanta. The body size of adult fish is 4-4.5 centimeters. Coloring depends on the region of habitat of individuals. The most common color options are bluish-yellow or yellow-olive with a silver tint. Along the body of these zebrafish pass two parallel twisting stripes of a light yellow hue.

• Point Danios - A variety of ray-fin fish found in freshwater waters of Myanmar. Visually, this species resembles other famous representatives of this genus - zebrafish. The average size of adult point zebrafish is about 4 centimeters. The color of these fish looks spectacular - white-golden sides and olive-brown back. Turquoise-black stripes stretch along the body.

• Danio rerio - one of the most popular species of fish belonging to this genus. The size of adults reaches 4–4.5 cm. The body is elongated, slightly elongated, covered with alternating turquoise-blue and light golden stripes. The fins are translucent, light. The caudal and anal fins are striped, repeating the coloring of the body.

• Genetically modified form is very unusual. zebrafishcalled GloFish. An amazing feature of these colored aquarium fish is their fluorescent color, glowing in the ultraviolet stream. In this case, the body color of the fish depends on what foreign proteins are present in its genotype. So, the presence of jellyfish DNA provides individuals a light green color, and red coral DNA provides purple.

• Other interesting representatives of breeding forms are veil rerio. The distinctive features of these fish are a beautiful veil tail and fins. The length of the tail and fins in adults can reach 2 or more centimeters.

• Pink zebrafish - one of the most beautiful representatives of a kind. It is customary to distinguish between true and artificially derived pink zebrafish. For true, pale pink with a metallic tint is characteristic, for the artificially derived form - a deep pink body color, diluted with longitudinal silver stripes. The size of adults can vary from 4 to 5 centimeters.

When choosing fish, you should pay attention to their behavior. This criterion often makes it possible to distinguish healthy individuals from patients. For zebrafish, slowness, lethargy and inactivity are not characteristic. These representatives of the aquarium fauna are always distinguished by increased activity, agility, and energy. Before buying fish, you must carefully inspect. The fins should be intact, even and straight.

The body of the fish should have a color corresponding to its variety. In addition, the examination should not reveal signs of any disease. In particular, a strange plaque on the body and fins, white grains, wounds, growths may indicate this. A healthy individual has an even, slightly rounded, but not swollen abdomen. A hollow or bulging abdomen can be a sign of digestive system diseases.

You should not purchase zebrafish, which have the following features:

• often or with force swallow air;
• tumble down on one side;
• do not rise from the bottom;
• greedily swallow air, floating at the surface of the water;
• rushing around the aquarium or continuously spinning in one place.

Despite the fact that zebrafish are considered undemanding fish, their health and life expectancy largely depend on the conditions of detention. So, trying to provide pets the most comfortable existence, you should pay attention to several criteria.

So that the inhabitants of the home reservoir do not feel constrained and uncomfortable, the aquarium should be quite spacious. Experienced aquarists argue that one zebrafish should account for at least 4–5 liters of the total tank volume. In this way, the minimum capacity of a home reservoir reserved for keeping a zebrafish school of 5 medium-sized individuals should be 25–30 liters. In addition, when choosing a suitable tank for these active fish, preference should be given to sufficiently long structures with a lid. It is important to consider that these fish are very mobile and are able to jump out of the tank during the game.

The zebrafish in the aquarium will look most spectacular, the bottom of which is covered with dark soil. It can be small river or sea stones of rounded shape, black volcanic sand. Before filling the tank, the selected type of soil should be disinfected - calcine on a fire or boil.

Experienced aquarists recommend that when arranging an aquarium for zebrafish, worry about proper lighting of the tank. The daylight hours for these fish should be at least 12 hours. You can solve the problem with aquarium lighting by installing a lamp or inserting a lamp into the tank lid.

The most comfortable temperature for these fish is water temperature, varying between + 18– + 23 °. Control the temperature of the water using an aquarium thermometer.The acidity of water should vary within 6–8 pH, hardness - 5–18 °. It should be remembered that hard water and water with a large amount of extraneous impurities are not suitable for these fish. Once every few days it is necessary to carry out a partial renewal of the water in the tank.

Most preferred for these fish are live feeds. Unlike catfishes who prefer to eat from the bottom, motile zebrafish feed on the surface of the water. For this reason, it is worthwhile to select floating varieties of feed for them. Bloodworms, daphnia, cyclops - both fresh and frozen, are perfect for these fish. When purchasing these types of feed, you should pay attention to the quality of the product.

They like to eat these fish and dry foods. In the assortment of modern stores you can find various types of dry feed enriched with protein, vitamins, carotenoids. The most popular brands are Tetra and JBL. Feeding these charming creatures is recommended twice or thrice a day in limited portions. Uneaten food debris should be removed from the aquarium - so the water will stay clean longer.

Despite the fact that zebrafish belong to unpretentious aquarium fish that can survive in conditions of oxygen deficiency in water for quite some time, they still need air. To a greater extent, it needs fish contained in a flock in a small aquarium. So that pets do not suffer from a lack of oxygen, when arranging an aquarium, it will be necessary to install aeration equipment.

Water aeration is also essential when the temperature level approaches maximum limits. With increasing temperature, the amount of oxygen dissolved in water decreases significantly, which negatively affects the well-being of the inhabitants of the aquarium. Installation of filters will allow to keep the purity and freshness of water longer. This will help reduce the frequency of harvesting, which often causes stress and discomfort in fish.

Make beautiful aquarium with bright zebrafish fish even more spectacular will allow beautiful scenery and plants. As a decor, you can use driftwood, grottoes and caves, tree branches, shells and corals, ceramic and glass products. These items not only give the home reservoir a complete look, but also provide shelter for the fish. It is noticed that the zebrafish, frightened of something (people, loud sounds, flashes of light), hides in a shelter or among plants. If there are no one or the other in the aquarium, this will exacerbate stress for all the inhabitants of the home reservoir. Almost all known types of aquatic vegetation can be planted in the zebrafish tank.

In breeding zebrafish fish usually does not arise difficulties. Quite often, these charming creatures give birth to offspring without any external stimulation. However, in some cases, it is possible to artificially create conditions for them to procreate. It should be clarified that zebrafish are not viviparous fish, and their offspring develop from caviar.

To get offspring from zebrafish, you need to drop a couple of heterosexual individuals in the spawning ground (you can drop 1 female and 2 males). To distinguish between fish-boys from fish-girls allows their size and brightness of color. As a rule, females are always slightly larger than males, and their coloration is paler. In females who are ready for procreation, the abdomen will be more rounded and enlarged. Males, ready for breeding, will differ from other individuals in a more intense color.

Before spawning, a separate aquarium should be prepared. So, on the bottom of the tank, which performs the function of spawning grounds, it is necessary to lay a layer of soil or lay a grid with small cells. Low water plants with dense, fine and soft foliage are also suitable. The arrangement of the bottom in this case is necessary to mask the eggs, which adults can eat after spawning.

The tank is filled to the middle with water, an aerator is connected to it and the water temperature is increased to + 24 °. After that, the temperature is gradually reduced, adding cool, settled water to the tank. It is necessary to reduce the temperature to + 20– + 21 °. Such conditions contribute to the stimulation of spawning, which usually occurs within 1-3 days. After the female marks the eggs, she and the males are transplanted into a common aquarium for the rest of the fish. In spawning grounds, the temperature is again increased to approximately + 27– + 28 ° С. This will speed up the ripening of eggs.

Around 2–3 days, tiny long larvae will begin to appear from the eggs. It should be borne in mind that they grow quite quickly and turn into fry, and then into full-fledged individuals. During the process of transformation of larvae into fry (and later, as the fry themselves develop), the resulting zebrafish offspring are fed with egg yolk, ciliates, and artemia. As soon as the fry are a little older and stronger, they can be transferred to the same food that adults eat.

The peaceful and friendly disposition of the zebrafish allows them to easily get along in the home pond with a variety of representatives of the aquarium fauna. They are wonderful neighbors for any medium-sized and non-predatory fish. So, the following fish will be good neighbors for zebrafish:

• guppies;
• molliesia;
• thorns;
• small catfish;
• neons
• Pecilia
• gurus
• rainbow fish.

Zebrafish with scalaria, with which they can exist seamlessly throughout life, get along quite well. The only drawback is that aquarists believe that during mating season and expectation of offspring, scalaria can behave more aggressively towards zebrafish. This behavior is due to the instinctive desire of scalars to protect their future offspring. Frisky and conflicting barbs, which drive peace-loving fish throughout the aquarium, bite and damage their fins, are not suitable as zebrafish neighbors. It is undesirable to keep zebrafish with shrimps, the young of which for these fish is a delicious delicacy. In addition, experienced aquarists argue that the presence of zebrafish in the same shrimp tank causes severe stress in the latter.

Goldfish, which are superior to zebrafish in size, and also require completely different conditions of detention, are not suitable as neighbors. In the event of a conflict, a goldfish can injure a zebrafish and even kill it. In addition, goldfish feel most comfortable in cool water, while zebrafish prefer warm water. It is strictly forbidden to contain zebrafish with large and / or predatory representatives of the aquarium fauna. Thus, medium and large species of aquarium catfish, astronotuses, cichlids, and discus represent a mortal danger for these peace-loving creatures. Once in the same tank with these species of fish, the zebrafish will have no chance to survive.

For more information on the care and maintenance of zebrafish, see the video below.