Blue Line Tetra (Hyphessobrycon Cyanotaenia 'Imperial Lapis')

Hyphessobrycon cyanotaenia arrives as a striking, compact tetra from the Characidae family, celebrated for its clean, science-backed identity as it appears in the aquarium hobby. Redescribed from extensive material, this small fish carries a distinctive cyan mid-lateral line that runs from the upper half of the posterior margin of the eye to the middle caudal-fin rays, making it immediately recognizable among similar tetras.

Key identification features

• Clear cyan mid-lateral stripe: a crisp, uninterrupted line from the eye toward the tail that sets it apart from its congeners.
• No humeral blotch: a clean body silhouette that emphasizes the cyan line.
• Anal fin rays: 16–19 branched rays.
• Maxillary dentition: 2–4 teeth.
• Pelvic fins: six branched rays.
• Eye pigmentation: absence of dark pigmentation crossing the eye, contributing to a brighter head profile.

Size, coloration, and gender cues

This species remains compact in the aquarium realm: males can reach about 3.3 cm in length, while females stay slightly smaller, to roughly 2.8 cm. In terms of coloration, the male typically displays more vivid coloration, offering a lively focal point in a species-appropriate display. Its small, streamlined body paired with the striking cyan line makes for a visually engaging addition to any appropriate community setup.

Origin and natural habitat

Hyphessobrycon cyanotaenia traces its roots to the Rio Papagaio, a tributary of the Rio Juruena in the Rio Tapajós basin of Brazil. In the wild, these fish inhabit river biotopes edging forested areas where tannins and other organic substances color the water, creating acidic, tea-stained conditions. This biotope context informs its aquarium needs and helps explain its distinctive coloration and markings.

Why this species stands out in the aquarium

• Distinctive cyan midline provides immediate visual appeal, even in mixed-species tanks.
• Compact size supports a lively, multi-tetra display without dominating the tank.
• Redescription and clarified distribution offer a scientifically grounded, authentic hobbyist experience.
• Low-key, high-contrast patterning helps new keepers identify and appreciate a true Hyphessobrycon genus representative.

Care considerations and display tips

Reflecting its natural, tannin-rich habitat, Hyphessobrycon cyanotaenia thrives in water conditions that favor gentle acidity and stable parameters. When planning a setup, consider recreating a soft-water, lightly tinted environment with natural decor that provides shaded areas and gentle cover. The fish’s small size and striking line make it an excellent candidate for a peaceful, small-tetra display alongside other small, non-aggressive species.

Taxonomy and background

Belonging to the family Characidae, Hyphessobrycon is a diverse genus with roughly 150 described species. Hyphessobrycon cyanotaenia has a documented history in scientific literature and in the aquarium trade, where its distinctive features are used to distinguish it from related taxa. The species’ formal description and subsequent redescription reflect ongoing efforts to accurately map its distribution and morphological range.

Enhance your freshwater lineup with Hyphessobrycon cyanotaenia and enjoy a vivid, scientifically interesting small tetra that pairs well with careful biotope-oriented aquariums and thoughtfully chosen tank mates.