Celebes Halfbeak Care Guide - Aquarium Setup, Diet & Breeding

The Celebes Halfbeak is a small, distinctive livebearer with a slender body and an unusual lower jaw that extends beyond the upper jaw. This specialised mouth gives the species its halfbeak appearance and helps it feed at the water’s surface. Males are particularly striking, developing iridescent blue-green colouring, orange or red markings and elongated fins.

These fish are active, alert surface-dwellers that spend much of their time just below the waterline. Males may display to one another and to females, spreading their fins and showing off their colours, but serious aggression is uncommon when they have enough space and are kept in a suitable group.

In the wild, Celebes Halfbeaks inhabit warm, relatively clear freshwater environments with gentle flow and vegetation around the margins. Their surface-oriented body shape reflects a lifestyle focused on insects and other small prey that fall onto or live at the water’s surface.

Nomorhamphus liemi is one of the more popular halfbeaks in the aquarium hobby because of its unusual shape, attractive adult males and livebearing reproduction. Like many fish from Sulawesi, it appreciates stable, mineral-rich water and can be sensitive to sudden changes in conditions.

Celebes Halfbeaks are native to Sulawesi, Indonesia, where they occur in freshwater streams, pools and quiet waterways. They are associated especially with the island’s southern and southeastern regions.

A group of Celebes Halfbeaks should have at least 60 litres, with a tank around 60 cm long by 30 cm wide or larger providing useful swimming space. A secure lid is essential because these active surface fish can jump. Use gentle filtration and leave an open area at the surface, while adding floating plants, fine-leaved vegetation, wood and smooth rocks around the margins. A dark fine-grained substrate can enhance their colours, though the substrate itself is not critical. Stable, well-oxygenated, moderately hard water with some surface movement suits them well.

Females reach about 7 cm (2.8 in), while males are smaller at approximately 5 cm (2.0 in).

Offer a varied diet of small floating flakes, micro-pellets and frozen or live foods such as mosquito larvae, daphnia, brine shrimp and small insects. Their upturned mouth makes surface-feeding foods especially appropriate. Regular vegetable-based foods can be included, but animal-rich foods should form a substantial part of the diet, particularly for growing fish and females carrying fry.

Celebes Halfbeaks can live with peaceful, similarly sized fish that prefer warm, neutral to alkaline water, including small rainbowfish, peaceful rasboras, hardy small barbs and other calm livebearers. Bottom-dwelling companions such as small Corydoras and peaceful loaches may also work where water chemistry is suitable. Avoid large or predatory fish, fin-nippers and very boisterous species, as well as slow, long-finned fish that may be harassed. Keeping several females per male helps reduce persistent courtship pressure.

Celebes Halfbeaks are livebearers and breeding groups are best formed from several females with fewer males. After internal fertilisation, the female gives birth to relatively large, free-swimming fry over a period of several weeks. Dense floating plants provide cover for young fish, although adults may eat some of the fry. Feed the female generously with small, nutritious foods, and move the fry to a separate nursery or heavily planted section if a high survival rate is important.

Females are noticeably larger and fuller-bodied than males. Males are smaller and more colourful, with more extended dorsal, anal and caudal fins and stronger orange, red or blue-green markings.