Hemigrammus vorderwinkleri

Overview

A very peaceful small tetra from Negro blackwater, Hemigrammus vorderwinkleri sometimes arrives as a few individuals mixed into other imports. It suits a sheltered group aquarium without competition from large, forceful companions.

Distribution & habitat

Known from Brazil’s Negro River and tributaries, it occupies acidic blackwater stained brown by substances released from decaying organic material.

Aquarium setup

Use sand, wood, roots, and dried leaves to provide shade and lightly stained water. Replace heavily decomposed leaves before they foul the setup. Keep light subdued. Plants are optional, although a well-maintained planted aquarium also works. Fish entering trade are very likely wild-caught.

Diet & feeding

Small invertebrates dominate its wild diet, but settled aquarium fish are adaptable. Offer fine flakes or granules with small live and frozen foods for variety.

Behaviour & compatibility

Keep at least six, ideally ten or more. Peaceful tetras, pencilfishes, small catfish, and suitable dwarf cichlids are options. Other gentle small fishes must share compatible water needs. Avoid very active or substantially larger companions that dominate food and space.

Sexual dimorphism

Adult males are usually slightly smaller and slimmer, with a hook-shaped anal fin.

Breeding

Prepare a separate dim aquarium with fine plants or mops and either mesh or dense planting to shelter eggs. Gentle sponge filtration is sufficient. Condition fish for group spawning or select a pair after feeding the sexes separately. An evening introduction may lead to spawning the next morning when fish are ready.

Remove adults afterward to prevent egg predation. Eggs hatch in roughly a day to a day and a half; fry swim freely another three to four days later. Start with infusoria-sized foods before microworms or Artemia nauplii. Keep eggs and early fry shaded because they are light-sensitive.