If you have ever seen a school of small fish with bright red heads in an aquarium, then you are probably familiar with rhodostomus. These miniature beauties are among the most recognizable and beloved inhabitants of freshwater aquariums. Their calling card is their contrasting coloration: a rich scarlet spot on the head, transitioning into a silvery body with a black and white stripe at the tail.
Rhodostomus are valued not only for their beauty, but also for their characteristic behavior. They are schooling fish that feel confident and safe only in a group of their own kind. Watching the coordinated movement of the school is a real pleasure. They enliven the middle and lower layers of the water, giving the aquarium dynamism and natural charm.
Keeping these fish is not too difficult, but there are important nuances. They need clean, “mature” water with stable parameters and mild acidity. They are quite sensitive to sudden changes and the quality of their environment. If you create the right conditions for them — a spacious aquarium, subdued lighting, dense vegetation, and calm neighbors — rodostomus will delight you for a long time with their activity and rich colors.
Habitat, characteristics of life in nature
In nature, rodostomuses can be found in South America in the Rio Negro, Rio Vaules, and Amazon tributaries. Since the rivers are located in tropical forests, they are shaded, and there are few plants at the bottom. However, rotting plant debris constantly floats on the surface, providing a slightly acidic environment.
Rodostomus live in schools and prefer the upper and lower parts of the water. In nature, they hunt for larvae and insects.
Fish characteristics
Their elongated body is silvery with a neon tint. Their nose is red, but it turns pale if the fish is frightened, stressed, or living in unfavorable conditions. The tail is striped, with 3 black stripes between 4 white ones. The fish grow to a maximum length of 5 cm.
Sexual dimorphism is weakly expressed. The female can only be distinguished from the male during the spawning period, when her abdomen enlarges due to the eggs.
Rodostomus is a beautiful aquarium fish from South America that attracts with its bright color and calm nature. There are several species, the most popular being Rodostomus harlequin and Rodostomus cardinal, which differ in color but behave in much the same way. These fish are small, peaceful, and perfectly suited for community aquariums with other small inhabitants. They need warm, clean water, plant cover, and a balanced diet. The main thing is not to keep them alone: they are schooling fish and feel better in the company of their own kind, at least 6 individuals. With proper care, rodostomus live long and are pleasing to the eye.
Contents
Keep rodostomus in groups of 6-8 individuals. The aquarium should be at least 50 liters, but it is better to choose a tank with a volume of 70-100 liters. It is advisable to plant a large number of aquatic plants to make the fish feel more comfortable.
They prefer slightly acidic (5.0-7.0 pH) soft (2-15 dH) water. This is a freshwater species. The optimal temperature ranges from +24 to +28 degrees.
Filtration and aeration are necessary. One-third of the water should be replaced weekly. If the water is contaminated with ammonia or nitrites, the heads of the rodostomus turn pale. It is important to replace the water as soon as possible, otherwise the fish will die.
The light should not be too bright; rodostomus feel more comfortable in dim lighting. In winter, the length of daylight hours should be 12 hours. In summer, if the aquarium receives sufficient natural light, the lighting should be turned off early.
— Yaroslav Breeder of characins from Volgograd
Rodostomus can be fed both dry food and live food. It is better to alternate between the two. They do not collect food from the bottom. Since their mouths and stomachs are small, feed them in portions. This will also solve the problem of sedimenting residues.
Choose pellet or flake food: large larvae are difficult for rhodostomus to eat. Frozen chopped bloodworms are suitable as live food. They should be given in small amounts so that the fish do not become obese.
Breeding
For breeding, you will need a smaller aquarium with a volume of 20-25 liters. Lower the water hardness to 8-10 dH and increase the temperature to 30-32 degrees. Dim the light. Feed the breeders generously with mixtures with an increased protein concentration. An important condition is the absence of neighbors. Place a separator net on the bottom. This measure will protect the eggs from their own parents.
Adult specimens are transplanted after spawning. The larvae emerge from the eggs within 36 hours. It is important that the container with them is kept in a quiet place where the young will not be disturbed by extraneous noises. To make the fish feel more comfortable, plant a few aquatic plants at the bottom. This will allow the rodostomuses to find shelter and feel safe.
Subspecies
The closest relatives of rodostomus are considered to be:
Unlike the rodostomus, which only has a red tip on its snout, this species has redness spread across its entire head.
This fish has a red upper head.
Compatibility
Rodostomus should be kept in schools of at least 6 individuals. With fewer individuals, the fish will become skittish. This is a peaceful species that does not show aggression towards its neighbors, but sometimes causes them inconvenience due to its activity.
Goes well with:
They get along with shrimp and do not show any gastronomic interest in them.
Do not place rodostomus with aggressive species, such as cichlids.
More care tips:
Advice for owners
To make the fish look more impressive, you can create a “black water” effect. To do this, pour oak bark decoction into the aquarium. You will have to repeat the procedure regularly, as with good filtration and weekly water changes, the effect does not last long.
The temperature affects the fish's metabolism. If you want larger specimens, stick to the lower limit. Rodostomus cannot reproduce in cold water. In warm water, the fish are active and capable of reproduction, but their lifespan is reduced.
To dim the light, you can place floating plants such as pistia and philanthus at the top of the aquarium.
Fish are sensitive to changing environmental conditions, so it is not recommended to place them in a newly started aquarium. Due to sudden changes in water parameters, rodostomus may experience stress and even lie on their side at the bottom, making them look like they are dead.
Video review of the rodostomus
Rodostomus are amazing fish that can become a real decoration for your aquarium. Their main feature is a bright red spot on their head, which really enlivens the underwater picture. If you are ready to provide them with comfort and clean water, they will delight you with their activity and beauty for a long time.
Keep in mind that these fish are quite demanding. They need stable, clean, and soft water, as well as the company of their own kind. If you create the right conditions for them, they will reward you with excellent health and may even delight you with offspring.
Overall, keeping rodostomus is an interesting and rewarding experience for aquarists. They are suitable for those who already have some experience and want to get some truly spectacular and interesting fish. With proper care, they will become one of the most beloved inhabitants of your home aquarium.
