Aquarium with cyprinid family fishes.
Continued…
Aquarium with Devario and Danio.
Peaceful, especially towards fast-swimming species. Very active schooling fish, often jump out of the water. According to their size and lively temperament, they need a more spacious enclosure; the aquarium should be elongated. They need a spacious, elongated aquarium planted with vegetation along the edges, but with plenty of open swimming space. The aquarium should be covered at the top because the fish can jump out of the water when frightened. Place driftwood, rocks, and other bottom decorations along the edges. Substrate: small pebbles or gravel.
These are peaceful, very active, schooling fish (they always swim in a school), staying in all water layers. Keep only in a school of 6-8 or more fish. They stay predominantly in the upper and middle water layers. When a school of *Danio rerio* rushes swiftly through the aquarium, skillfully maneuvering between densely located stems and leaves of plants without touching a single one, it seems completely incomprehensible why the little fish needs its bright striped coloration. But if the aquarium is planted with Vallisneria, the ends of whose leaves lie on the water surface, one can easily make sure that this is far from the case. A sudden knock on the lower part of the glass to frighten the fish makes them instantly rush upward, where their body stripes are barely noticeable among the leaves sprawling on the surface.
They can be kept in a general aquarium, preferably with active fish. They get along well with various species of fish that prefer bright lighting. *Danio* can live in aquariums and any small-volume containers, but elongated ones with plants and plenty of swimming space, necessarily covered with glass, are better. The aquarium should be planted with strong and not very tall plants along the edge, and the middle part can be decorated with roots and a few stones to ensure a significant swimming area. One of the distinguishing features of this fish is its extraordinary mobility.
When keeping devario in a school, it is especially interesting to observe the group behavior of these fish. The dominant fish in the school swims horizontally. This is a position that provides the opportunity to instantly rush forward and upward to grab prey or escape from an enemy. The remaining members of the school of these fish swim with a greater or lesser forward and downward tilt of the front part of the body.
The tilt angle is determined by the fish’s rank position in the school. Thus, the subdominant — the second-ranking fish in the school — stays with only a slight tilt. The tilt angle during the swimming of other fish is determined by their position in the school hierarchy, increasing as their “authority” in the community decreases. Fish holding a higher position in the school strictly monitor that the “lower ranks do not turn up their noses.” The leader and his close associates stay in the middle of the school and much less often become victims of predators than their weaker “lower ranks,” which form a kind of living barrier protecting the best in the community.
Undemanding regarding the chemical composition of water. They prefer clean, oxygen-rich water. *Danio* are quite adapted to large but gradual temperature drops within 15-30°. The best temperature for them is considered 22-24°C, less desirable 18-22°C. Aeration is necessary since danios love transparent, oxygen-rich water. Weekly water changes are mandatory; they prefer fresh water.
Food is live, dry, and vegetable, quite diverse; they eat all types of traditional aquarium foods. As soon as the food touches the water surface, they grab it immediately. It is very good to feed these fish with *Daphnia* and *Cyclops* — when the fish hunt for live food released into the aquarium, they are constantly in motion, dashes to the prey follow one another. They take food from the bottom reluctantly. If part of the food has fallen to the bottom, the fish will go down for it, although danios are considered typically top-dwelling fish. Managing to get well-fed in any company of fish, danios live long and rarely get sick.
Hardy, resistant to diseases. This is not only one of the most resilient aquarium fish, but it is also very easy to breed. Even novice aquarists can keep and breed them.
Aquarium with rasboras.
This genus is widely distributed in the water bodies of South and Southeast Asia, Indonesia, and the Philippines. Representatives of the genus *Rasbora* are mostly schooling fish that stay in the upper layers of standing and slow-flowing waters. Many species spawn in large groups. As a rule, rasboras are small or very small fish with an elongated and more or less laterally compressed body.
Keeping most species requires elongated, spacious aquariums, densely planted along the side and back walls, with a sufficiently large swimming space. Crowding, as well as an excess of dissolved organics in the water, cause stress in fish and suppress the body’s defense mechanisms. The fish are mostly in the upper third of the water volume and prefer a weak current. Thickets must be arranged in the aquarium; they prefer as dark a bottom as possible. They love shady places, dense vegetation, and floating plants are needed. They do not damage plants and are suitable for keeping in a Dutch aquarium.
Peaceful, active fish, they can be kept together with other calm aquarium inhabitants; the best neighbors are tetras, other species of rasboras, and small barbs. Rasboras are kept in groups of at least 6-10 individuals with a predominance of females, but all the splendor of coloration and natural behavior are manifested only in a school.
The water should be of medium hardness with a slightly acidic reaction. They love old water with the addition of peat. Soft, peat-filtered water, temperature 24-25°C. Aeration, filtration, and water changes are desirable. Very sensitive to oxygen deficiency and excess rotting organics. Lighting is not too bright. Rasboras are delicate fish, do not like prolonged overcooling, are prone to diseases, and are sensitive to oxygen deficiency and excess rotting organics. Fish are indifferent to a gradual increase in salinity up to 4-5%.
Unpretentious to food, they consume any live and dry food, including those with vegetable ingredients. They eat any live food, as well as dry food, but only in combination with something else.
Aquarium with cyprinid fishes. Large barbs, Fishes of the genus Barbus, Puntius. 
