Boraras merah

Adult individuals of this fish reach a length of only about 2 cm. Their coloration is predominantly red, with a grayish back. The main distinguishing feature in their body pattern is a prominent black spot located on a reddish background. Sexual dimorphism in Boraras merah is not pronounced, manifesting mainly in size: females are generally somewhat larger and have a more rounded abdomen. Males, on the other hand, boast a more intense coloration, although this difference is not always obvious.

The southern part of Borneo Island, located in Southeast Asia, is endemic to this species. Here, Boraras merah inhabits swamps, as well as rivers and streams flowing under the dense canopy of the tropical forest. The natural bodies of water where this species lives are notable for their brown water color, which is due to a high concentration of tannins. These compounds are released during the decomposition of organic matter, as fallen leaves, twigs, and other plant debris usually accumulate at the bottom of such bodies of water. Unfortunately, today the habitat of Boraras merah is under serious threat due to active human activities, including the development of palm and rubber plantations, as well as oil extraction.

This peaceful schooling fish will perfectly complement a community of other miniature species. However, it is advisable to avoid keeping them with larger tankmates who may pose a potential threat to such small creatures. It is recommended to keep Boraras merah in groups of at least 8–10 individuals; with fewer, they become timid and will likely spend most of their time hiding.

For a small school of Boraras merah, an aquarium of 20–30 liters is sufficient. The setup should imitate their natural habitat as closely as possible: it is recommended to use a sandy substrate, as well as many shade-loving and floating plants and various snags. Lighting should be subdued. To achieve the characteristic brown tint of the water, you can add fallen leaves from European trees or more exotic ones, such as Indian almond leaves and bark. You can learn more about this in the article “Which tree leaves can be used in an aquarium.” Maintaining this species is relatively simple and includes standard aquarium procedures: weekly partial water changes, regular removal of organic debris (excrement and uneaten food), and maintaining stable water chemistry parameters. When choosing a filtration system, preference should be given to models that do not create a strong current, as these fish originate from still waters and are not adapted to intense water movement.

In the wild, these fish feed primarily on small zooplankton. In a home aquarium, they readily accept most common foods, provided they are of appropriate size. These can be dry, fresh, or frozen foods. The daily diet can be formed by including dry flakes or granules in combination with daphnia and artemia. It should be noted that protein-rich food helps improve their coloration and maintain the overall vigor of the fish, which is especially important during the breeding season.

Under favorable conditions, if sexually mature males and females are present in the school, spawning occurs quite frequently. The fish scatter many eggs, which sink to the bottom and from this moment are left without parental care. Moreover, the newly hatched “parents” may eat their own eggs. For this reason, fry rarely survive to adulthood in a community tank. If you plan to save all (or part) of the offspring, you need to prepare a separate tank of 10–15 liters in advance with identical water conditions. This breeding aquarium can be equipped with a simple sponge filter, a heater, and a lighting system. A few shade-loving plants or ferns will be sufficient for decoration. After spawning is complete, the eggs are carefully transferred to this separate aquarium. The incubation period lasts about two days, and after another day, the fry begin to swim freely in search of food. At this stage, the main task is feeding them. Tiny fry require appropriate food: infusoria or specialized powdered foods would be ideal. As the fry grow, their diet can be supplemented with Artemia nauplii.

Cottelata brittani is a hardy and undemanding fish. When suitable keeping conditions are met, health problems usually do not arise. Diseases can appear in cases of injury, contact with already sick fish, or a significant deterioration of habitat parameters (for example, in a dirty aquarium or with poor nutrition). More detailed information on symptoms and treatment methods can be found in the section "Diseases of aquarium fish."

When purchasing Boraras merah, it is important to ensure there are no signs of emaciation or fin damage, as due to their miniature size, these fish are sensitive to stress and transportation. Healthy individuals should be active, exhibit typical schooling behavior, and have a bright, species-specific coloration without spots or film on their bodies. Avoid purchasing fish from aquariums where dead specimens or fish showing signs of timidity and lethargic behavior are observed, as this species is susceptible to diseases if kept in improper conditions.