Bulungan Betta

Adults of this species reach 9–10 cm in length. The Bulungan Betta is considered a close relative of Betta unimaculata, sharing many traits with it. The fish have a robust build and short fins. Their coloration ranges from grey to red. Males often display turquoise iridescence on the head and front of the body, unlike females.

This species originates from Southeast Asia. Its home is small streams running through hilly jungle terrain in the Indonesian part of Borneo, in East Kalimantan province. The typical habitat consists of dimly lit, shallow streams with clear water, where the substrate is made up of rocks, sand, and abundant plant debris such as leaves, branches, and wood. The banks are usually densely overgrown with shade-loving plants, mosses, and ferns.

As a betta species, this fish shows certain behavioral traits. These appear mainly as rivalry between males for dominance and the attention of females, often resulting in fights. However, serious injuries are usually rare. In a small tank, keep either one male with several females or a single pair. Toward other fish species, the Bulungan Betta is peaceful. It gets along well with non-aggressive fish of comparable size.

A pair requires an aquarium of at least 70–80 litres. Although the Bulungan Betta is not particularly demanding in terms of decor, some aspects should be considered. Provide dimmed or diffuse lighting, which can be achieved with floating plants, for example. Shelter is also necessary, which can be in the form of wood or various decorative items. Like any fish from wild flowing waters, the Bulungan Betta needs clean water. Avoid accumulation of organic waste—uneaten food and excrement—by cleaning regularly and maintaining the required water chemistry within the acceptable temperature range. Beyond routine tank maintenance, an effective filtration system is essential.

In nature, the diet of the Bulungan Betta consists mainly of insects and other invertebrates. In a home aquarium, feeding should be adequate and include live or frozen foods such as daphnia, brine shrimp, bloodworm, mosquito larvae, and fruit fly. These can be supplemented with popular dried aquarium foods in the form of flakes and granules.

The parental care of the Bulungan Betta deserves special attention. Unlike many species, they do not lay eggs on the substrate or in plants where they might be lost; instead, they use a unique incubation method: eggs are carried in the mouth, and only males perform this role. During spawning, the male carefully collects several dozen fertilized eggs in his oral cavity. He then retreats to a secluded place away from other tank inhabitants. During this delicate time, it is very important to provide him with peace, as stress can lead to premature release or even swallowing of the eggs. Egg development takes approximately 2 weeks, after which fully formed fry emerge. From this point on, the male's parental care gradually diminishes.

Unsuitable keeping conditions are usually the cause of disease. Maintaining a stable environment in the tank is key to successful keeping. If any signs of illness appear, first check the water quality. If abnormalities are found, take immediate steps to correct them. If symptoms persist or even worsen, medication may be needed.

When choosing fish, prefer those raised in captivity, as a significant portion of specimens in the trade are wild-caught, which can negatively affect their adaptation. A healthy fish should be active, have clean fins without signs of damage or coating, and have a full body without visible hollows or wounds. Avoid purchasing fish showing signs of emaciation, lethargy, or rapid breathing, as these may indicate transport stress or hidden disease. Given the rarity of this species, it is recommended to ask the seller in advance about the tank conditions in the shop and the diet to which the fish is accustomed.