Zebrafish: varieties, selection, care, reproduction

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

Danio is a genus of small ray-finned fish belonging to the carp family. The original habitat of these charming creatures is the freshwater areas of Southeast Asia. The average size of adults varies from 4 to 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 widely used in the aquarium hobby. They are not too pretentious to care, they easily breed in captivity. To date, scientists have developed a number of interesting breeding forms with colors, sizes and shapes of fins atypical for fish of this genus. One of the breeding forms of zebrafish - transgenic (GloFish) - makes a strong impression.

One of the striking advantages of aquarium zebrafish is their peaceful and non-conflict nature. They are energetic, very mobile, cheerful. The rest of the inhabitants of the zebrafish aquarium are neutral, without showing aggression.Like many other medium-sized representatives of the aquarium fauna, the life expectancy of zebrafish is not too long. The average life expectancy for small individuals is about 3 years, for large ones (9-10 centimeters long) - about 6 years.

A wide variety of these adorable fish are popular in the aquarium hobby. They all differ from each other in interesting and original colors, sizes, body shape and fins.

• Pearl zebrafish - a kind of beautiful freshwater fish, whose natural habitat is the waters of the Malay Peninsula and the island of Sumatra. Their body coloration depends on the region of origin. This zebrafish species has several basic color forms. The most common color is iridescent bluish, with an orange-red stripe running along the body and intensifying the color at 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 their genus. Their average body size rarely exceeds 2-3 centimeters. Body coloration - gray-olive with a metallic sheen. A bright orange-red stripe runs along the upper part of the trunk under the dorsal fin. Dark gray stripes are located across the body along the midline. 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 can 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 extending downward from the mouth. The color of the fish ranges from pinkish brown to silvery blue with a metallic sheen. The most common color options are silver or pinkish olive. The fins are translucent and most often of a light shade. Closer to the gills of the zebrafish dangil, there is usually a small, rounded mark of dark color.

• Kerry Is a species of zebrafish that lives in freshwater reservoirs in the southern part of the Malay Peninsula, as well as in streams and rivers of the nearby islands of Phuket and Ko Lanta. The body size of adult fish is 4–4.5 centimeters. Coloring depends on the region of habitation of individuals. The most common color options are bluish yellow or yellow olive with a silvery sheen. Along the body of these zebrafish there are two parallel winding stripes of a light yellow hue.

• Point zebrafish - a type of ray-finned fish found in the freshwater areas of Myanmar. Visually, this species resembles other well-known 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 an 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 color of the body.

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

• Other interesting representatives of breeding forms are veil rerio... 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 its kind. It is customary to distinguish between true and artificially bred pink danios. For true ones, a pale pink color with a metallic sheen is characteristic, for an artificially derived form - a deep pink body color, diluted with longitudinal silvery 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 distinguishes healthy individuals from sick individuals. Slowness, lethargy and inactivity are not characteristic of zebrafish. These representatives of the aquarium fauna are always distinguished by increased activity, agility, energy. Before buying fish, you must carefully examine it. Fins should be intact, straight and flat.

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

Do not purchase zebrafish that have the following features:

• swallow air often or with effort;
• fall on one side;
• do not rise from the bottom;
• greedily swallow air, swimming near the surface of the water;
• rush around the aquarium or spin in one place continuously.

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

So that the inhabitants of the home pond do not experience constraint and discomfort, the aquarium should be quite spacious. Experienced aquarists say that one zebrafish should have at least 4-5 liters of the total volume of the tank. Thus, the minimum capacity of a home reservoir for keeping a flock of 5 small zebrafish should be 25-30 liters... In addition, long enough lid designs should be preferred when choosing a suitable tank for these active fish. It is important to take into account that these fish are very mobile and are able to jump out of the tank during the game.

The zebrafish will look most impressive in an aquarium, the bottom of which is covered with dark soil. These can be small river or sea stones of a rounded shape, black volcanic sand. Before filling the tank, the selected type of soil should be disinfected - calcined over a fire or boiled.

Experienced aquarists recommend taking care of proper tank lighting when setting up a zebrafish aquarium. The duration of daylight hours for these fish should be at least 12 hours. You can solve the problem with the lighting of the aquarium by installing a lamp or inserting a lamp into the tank lid.

The most comfortable for these fish is the water temperature, which varies within + 18– + 23 °. The temperature of the water should be monitored with an aquarium thermometer.The acidity of the water should vary within 6–8 pH, hardness - 5–18 °. It should be remembered that hard water and water with a large amount of foreign impurities are not suitable for these fish... Once every few days, it is necessary to partially renew the water in the tank.

Live food is most preferred for these fish. Unlike catfish, which prefer to feed from the bottom, mobile zebrafish feed near the surface of the water. For this reason, it is worth choosing floating feed varieties for them. Bloodworms, daphnia, cyclops are perfect for these fish - both fresh and frozen. When purchasing these types of feed, you should pay attention to the quality of the product.

These fish and dry types of food are eaten with pleasure. In the assortment of modern stores, you can find various types of dry food enriched with protein, vitamins, carotenoids. The most popular brands are Tetra and JBL. It is recommended to feed these adorable creatures twice or three times a day in limited portions. Remove uneaten food debris from the aquarium to keep the water cleaner for longer.

Despite the fact that zebrafish are unpretentious aquarium fish that can survive in conditions of oxygen deficiency in the water for quite a long time, they still need air. To a greater extent, the fish contained in a school in a cramped aquarium need it. To prevent pets from suffering from a lack of oxygen, when arranging an aquarium, you will need to install aeration equipment.

Aeration of water is extremely necessary even when the temperature level approaches the maximum limits. As the temperature rises, the amount of oxygen dissolved in the water decreases significantly, which negatively affects the well-being of the inhabitants of the aquarium. Installing filters will keep the water clean and fresh for longer. This will help reduce the frequency of cleaning, which is often stressful and uncomfortable for your fish.

Beautiful decorations and plants will make an aquarium with bright zebrafish even more spectacular. As a decoration, you can use driftwood, grottoes and caves, tree branches, shells and corals, ceramics and glass products. These items not only give the home pond 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 neither one nor the other in the aquarium, this will exacerbate the stress for all the inhabitants of the home pond. Almost all known types of aquatic vegetation can be planted in the zebrafish tank.

Breeding zebrafish is usually straightforward. Quite often, these adorable creatures give birth to offspring without any outside stimulation. However, in some cases, you can artificially create conditions for them to reproduce. It should be clarified that zebrafish are not viviparous fish, and their offspring develop from eggs.

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

Prepare a separate aquarium before stimulating spawning. So, at the bottom of the tank, which serves as a spawning ground, it is necessary to lay a layer of soil or lay a mesh with small cells. Short aquatic plants with dense, small and soft foliage are also suitable. The arrangement of the bottom in this case is necessary to mask the eggs, which the 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 raised to + 24 °. After that, the temperature is gradually lowered by adding cool, settled water to the tank. It is necessary to reduce the temperature to + 20– + 21 °. These conditions help stimulate spawning, which usually occurs within 1–3 days. After the female marks the eggs, she and the males are transplanted into a common aquarium with the rest of the fish. In the spawning grounds, the temperature is again increased to about + 27– + 28 ° С. This will speed up the ripening process of the eggs.

At about 2-3 days, tiny long larvae will begin to emerge from the eggs. It should be borne in mind that they grow rather quickly and turn into fry, and then into full-fledged individuals. Throughout the process of transformation of larvae into fry (and further - as the fry themselves develop), the resulting offspring of zebrafish are fed with egg yolk, ciliates, brine shrimp. As soon as the fry grow up a little and get stronger, they can be transferred to the same food that adults eat.

The peaceful and friendly nature of the zebrafish allows them to easily get along in their home pond with a wide variety of representatives of the aquarium fauna. They are great neighbors for any small and non-predatory fish. So, the following fish will become good neighbors for zebrafish:

• guppy;
• mollies;
• thorns;
• small catfish;
• neons;
• platies;
• gurus;
• rainbow fish.

Danios get along pretty well with scalars, with which they can exist without problems throughout their lives. The only drawback aquarists believe is that during the mating season and the expectation of offspring, scalars can behave more aggressively towards zebrafish. This behavior is due to the instinctive desire of the scalar to protect their future offspring. Frisky and conflicting barbs are not suitable as neighbors for zebrafish, which drive peace-loving fish throughout the aquarium, bite and damage their fins. It is undesirable to keep zebrafish with shrimps, the young of which are a delicious delicacy for these fish. In addition, experienced aquarists claim that the presence of zebrafish in the same tank as shrimp causes great stress in the latter.

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

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