Black darter tetra

Poecilocharax weitzmani

Blue scale spots along a dark band, with enlarged fins in males

Blue reflective scale spots interrupt the dark lateral band, and a dark mark lies below the eye. No adipose fin. Mature males have elongated dorsal and anal fins; females have shorter fins and less conspicuous colour.

Adult length: Up to 5 cm (standard length, without the tail fin)
Water temperature: 21–28 °C
pH: 3–6.5
Hardness: 0–5 dGH

Native range: Native to the upper Solimões, upper Negro and upper Orinoco basins.

Natural habitat: Unknown

Not a conventional schooling fish. Males defend territories, and feeding competition may leave weaker individuals short of food. Monitor new fish closely.

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Appearance and identification

A member of Crenuchidae. The sailfin tetra Crenuchus spilurus is a different species, with an adipose fin and different tail-base markings.

Same-species behaviour

Male conflict can damage fins; consider sex composition, territorial space and escape routes together.

Space requirements

45 × 30 cm for a pair or one male with females. Additional males need separate territories, interrupted sightlines and retreats. Use mature stable water, shade and gentle flow.