Black stripe tetra

Hyphessobrycon melanostichos

Blue above a black stripe, with a shoulder mark extending below it

The band runs from behind the eye onto the central tail rays. Courtship males can look much darker and reddish-brown than this ordinary blue-silver form.

Adult length: Up to 3.7 cm (standard length, without the tail fin)
Water temperature: 23–28 °C
pH: 5.5–7.5
Hardness: 0–10 dGH

Natural habitat: Inhabits slow margins of clear, shallow rivers over sand and scattered small stones, with submerged and bankside vegetation.

Territorial males can remove scales and tear fins, especially in cramped tanks. Watch long-finned companions.

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Appearance and identification

Males are deeper-bodied, with a straight to slightly convex anal margin. Similar blue-striped trade fish need separate identity checks.

Same-species behaviour

Provide retreat space; a larger group does not guarantee that rivalry stops.

Space requirements

Allow a base of at least 60 × 30 cm; twelve or more suit a 90 cm-long tank.

Diet and feeding

Offer suitable dry and small frozen or live foods.

Compatibility limits

Monitor territorial disputes and fin damage.

Aquarium environment

Plants and wood can provide cover.

Sources

userweb.ucs.louisiana.edu ↗ 2026-10-23