Black Arrow Tetra (Pair)

An emperor drawn in charcoal. The Black Arrow Tetra has the compact, high-backed build of the Blue Emperor, but the palette is pared down to a dark lateral band, smoky body tones and clean pale fin edges. In a planted tank a small group reads as a set of sharp, dark darts cutting across the green — understated in the bag, quietly striking once the fish have settled in.

This fish reaches us sold as Inpaichthys luizae, a close relative of the familiar Blue Emperor, and it is still an uncommon sight in Indian shops. Its care runs along the same lines as Inpaichthys kerri: a peaceful, mid-water characin that wants clean, stable, softish water, a planted layout and the company of its own kind. Kept that way, it is a well-behaved and rewarding fish for anyone wanting a tetra that does not look like every other community tank.

Care Snapshot

Setting Up For It

• Planted sides, open centre. Dense planting along the back and edges gives the group security, while a clear mid-water lane lets males posture at one another — which is when the dark markings look sharpest.
• Dark substrate, softened light. A dark base and some floating cover push the contrast of the black band. Pale gravel under harsh white light washes the fish out.
• Driftwood and leaf litter. Wood and dried catappa leaves gently soften the water and add the tannin tint these Amazonian characins look most at home in.
• Gentle to moderate flow. Any well-maintained standard filter is fine; avoid a strong, unbroken current across the whole tank.
• Stable, mature water. Add them to a tank that has been running for at least six to eight weeks, and keep weekly partial water changes regular rather than large and occasional.
• Cover the tank. Like most tetras, they can jump when startled, especially in the first days after introduction.

Tank Mates

Males spar and posture among themselves; it looks dramatic but rarely causes damage.

Feeding — Small, Varied And Often

This is an unfussy feeder that takes food in mid-water and as it sinks. The aim is condition and colour rather than volume: small portions two or three times a day, eaten within a couple of minutes, keep the fish sleek and the water clean.

From the AQA range, a small granule or fine flake makes a reliable daily staple. Add frozen or live foods several times a week — this is what deepens the dark band and brings males into display.

Foods they take readily: frozen bloodworm, brine shrimp, daphnia, cyclops, mosquito larvae.

Sexing & Breeding

Sexing follows the emperor pattern: males are usually slightly larger, with longer, more extended fins and stronger markings once mature, while females are rounder-bodied and plainer. Differences are hard to read in young fish.

Expect egg-scattering behaviour in soft, slightly acidic water, with eggs laid among fine-leaved plants, java moss or a spawning mop. The adults will eat eggs and fry, so a separate spawning tank and early removal of the parents give the best results; newly hatched fry need infusoria or a liquid fry food first.

Keeping It In Indian Conditions

• Indian room temperatures suit it for most of the year; a heater is needed only for northern and hill-station winters.
• Keep summers in check. Above 28 °C in April and May, add extra aeration and run a fan across the surface.
• Soften very hard water. Moderately hard municipal supplies are workable, but hard borewell water should be blended with RO or rainwater for a fish of this type.
• Monsoon caution: dechlorinate every change and keep volumes modest while the municipal supply is unsettled.
• Easy to feed anywhere. Standard small dry foods plus frozen bloodworm or brine shrimp, both widely available in Indian cities, are all it needs.