Betta ocellata

Adults reach 8–9 cm in length. Males and females differ: males have a broader head, more elongated fins, and more turquoise in their colouration. Overall, these fish are grey and lack brightness.

Betta ocellata is found in Southeast Asia, specifically on the island of Borneo. Its natural range is limited to the Malaysian state of Sabah and the northern part of East Kalimantan. The species inhabits diverse biotopes, from fast-flowing hill streams to swampy forest areas hidden in dense jungle.

Males are aggressive and often conflict with each other, especially in a small tank. Fights over dominance in the hierarchy are common. A weaker male that loses may suffer constant attacks if it cannot find shelter from the dominant fish. Females face the same risk if bought separately from a male or kept in isolation for a long time; they may be seen as rivals. The ideal setup is a group of one male and several females raised together from a young age, plus other non-aggressive fish of similar size.

A pair needs an aquarium of at least 70–80 litres. Keeping Betta ocellata is straightforward if you follow a few key rules: maintain suitable water chemistry, avoid strong currents, provide a lid to keep the air above the surface warm and humid, use dimmed lighting or floating plants for shade, and add hiding places. Use natural elements like driftwood and plants, or decorations for shelter. Long-term health depends on reliable equipment, especially the filter, plus regular maintenance: weekly partial water changes and prompt removal of food scraps and waste.

In the wild, Betta ocellata eats small insects, invertebrates and zooplankton. In the aquarium, they readily adapt to alternatives. Feed them a mix of high-quality dried, frozen and live foods.

Breeding is straightforward if the fish are kept in suitable water conditions with appropriate temperature and chemistry parameters. The fish must come from the same group. Pairing a random male and female from different sources is not recommended. During the breeding season, the pair courts and bonds. Spawning involves the fish embracing tightly, coiling around each other. The male then takes the fertilized eggs into his mouth and incubates them for 12–17 days. The fry hatch fully formed and are ready to accept specialized micro-food for young aquarium fish.

Most health problems arise from poor keeping conditions. Stable, comfortable water is key to success. If signs of disease appear, check the water quality first. Address any problems immediately. If symptoms persist or worsen, medication may be needed.

When choosing Betta ocellata, look for an active fish that shows curiosity rather than hiding in corners. Inspect the body for damage, sores, white coating or signs of starvation—transport stress can affect the fish. Avoid specimens with an unnaturally swollen belly or sunken sides. Check the fins: they should be intact without splits or erosion. Watch the behaviour: aggressive fights among fish in the tank often signal overcrowding and injury. Ask the seller about the conditions and diet to ensure a smooth transition to your aquarium.