Red Halfbeak - Hemirhamphodon tengah

Red Halfbeak (Hemirhamphodon tengah)

The Red Halfbeak is a delicate and unusual freshwater surface-dwelling fish admired for its slender body, extended lower jaw and attractive red to orange line along the body. Also known as the Borneo Redline Halfbeak, this species is best suited to mature, peaceful aquariums with soft acidic water, subdued lighting, floating plants and very calm tankmates. It is a specialist fish that requires careful acclimation, stable conditions and a secure lid.

Common Name:
Red Halfbeak, Borneo Redline Halfbeak, Redline Halfbeak, Tengah Halfbeak

Scientific Name (Latin):
Hemirhamphodon tengah

Maximum Size:
Approximately 3.5–4 cm

Water Type:
Freshwater

Origin / Natural Habitat:
The Red Halfbeak is native to Borneo, particularly Kalimantan, where it is associated with soft, acidic freshwater habitats.

In the wild, it is linked with blackwater streams, peat swamp areas and quiet surface zones with overhanging vegetation, leaf litter, roots and subdued lighting.

This species spends most of its time close to the water surface, where it feeds on tiny insects, invertebrates and food items falling onto the surface film.

Water Parameters:
Temperature: 23–26°C
pH Range: 4.5–6.5
Hardness: Very soft to soft water preferred
Ammonia/Nitrite: 0 ppm
Nitrate: Kept very low and stable
Flow: Gentle surface movement only

Temperament:
Peaceful but delicate

Red Halfbeaks are peaceful surface fish, but they can be nervous and easily stressed by boisterous tankmates.

They are best kept with small, calm species that occupy the middle or lower levels and will not compete aggressively at the surface.

Diet:
Carnivore / Surface Micro-predator

The Red Halfbeak naturally feeds from the surface on tiny insects, larvae, small invertebrates and fine floating foods.

Offer suitably sized floating foods such as fine floating pellets, crushed flakes, fruit flies, mosquito larvae, daphnia, baby brineshrimp, cyclops and other small live or frozen foods.

Feed small portions carefully, making sure food stays near the surface and is not taken too quickly by faster fish.

Minimum Tank Size:
Approximately 45–60 litres for a small group

A longer, shallow-style aquarium is preferred over a tall tank, as this species lives close to the surface.

A secure, tight-fitting lid is essential, as halfbeaks are prone to jumping when startled.

Behaviour & Activity:
The Red Halfbeak spends most of its time close to the water surface, often hovering under floating plants or shaded cover.

It can be shy when first introduced and may panic if kept in bright, exposed aquariums.

A settled group will become more confident in calm conditions, especially when provided with floating plants, dark décor and gentle feeding.

Community Suitability:
Specialist Peaceful Community Fish

The Red Halfbeak is best kept in a quiet, mature blackwater-style aquarium or carefully planned peaceful community.

Suitable tankmates include small rasboras, peaceful tetras, dwarf pencilfish, small corydoras, kuhli loaches and other calm soft-water species that will not compete aggressively at the surface.

Avoid large fish, aggressive species, fin-nippers, boisterous barbs, surface-feeding competitors, gouramis, bettas, large killifish and any fish that may startle or outcompete them.

Special Requirements or Care Notes:
This is a specialist halfbeak that requires very stable, soft and acidic water.

Avoid hard alkaline water, bright bare aquariums, strong surface flow and aggressive tankmates.

Floating plants are highly recommended, as they provide cover and help the fish feel secure near the surface.

A tight-fitting lid is essential because this species can jump suddenly when startled.

Take care during netting and transport, as the extended lower jaw can be damaged easily.

Slow acclimation is strongly recommended, especially if moving the fish between different water chemistry.

Regular small water changes are better than large sudden changes.

This species is best suited to aquarists with experience keeping delicate soft-water or blackwater fish.

Suitable for:
Experienced

Availability:
Availability can vary depending on season and supplier. This species is usually an occasional specialist import.

All images are a visual representation of the fish you will receive, made to be as accurate as possible. Please note that Mother Nature is a wonderful thing, and variation in patterns and colours will occur — that is part of the unique beauty of these animals.