阿氏波鱼

Overview

The miniature blackwater fish Sundadanio axelrodi is peaceful and easily intimidated. Stable chemistry, very small foods, and careful handling are central to success. Local color forms include blue, green, and red-orange fish and are best maintained separately.

Distribution & habitat

The better-supported collection records concern Borneo, including Sarawak and parts of Indonesian Kalimantan. Suggested occurrences on Sumatra, the Riau Islands, and Bangka are less securely documented. Forest peat-swamp streams and pools provide extremely soft, acidic water, subdued light, and beds of leaves, twigs, and wood.

Aquarium setup

Use a mature, densely planted aquarium with gentle filtration. Soft sand, shaded woodwork, floating plants, and leaf litter reproduce useful aspects of its habitat. Decomposing leaves support microorganisms that can supplement fry food. Keep hardness very low and conditions strictly acidic. Avoid immature systems and sudden changes; regular replacements of about one-tenth of the water or less help maintain stability.

Exposure to air is poorly tolerated. Where possible, move fish into a bag or container underwater, use only a very soft fine net, and acclimate slowly by dripping water. Never lift a fish out merely to hear its sounds.

Diet & feeding

Small crustaceans, worms, insect larvae, and other zooplankton presumably form the wild diet. Newly imported fish may be weak and respond best to tiny live foods initially. Introduce frozen and prepared items once they settle, but do not assume every fish will accept dry food. Artemia nauplii, Daphnia, microworms, and finely chopped bloodworms provide useful variety.

Behaviour & compatibility

A dedicated group is a good choice; any companions should be similarly small, peaceful, and comfortable in soft acidic water. Keep at least twenty to thirty to reduce nervousness and encourage displays. Separate locality color forms to avoid possible interbreeding and loss of lineage information.

Sexual dimorphism

Males are slimmer and more intensely colored. Depending on the form, the front of their anal fin is dark or red, whereas the female fin is clear. Males can produce quiet sounds during disputes or stress; the precise mechanism has more than one proposed explanation.

Breeding

Successful hobby breeding has occurred, though sensitivity to changing conditions makes transfers into separate breeding tanks difficult. Larger groups kept alone in mature, heavily planted aquaria have given the best results. Stable soft acidic water, subdued light, plentiful microorganisms, and frequent live or frozen meals are important. With adequate shelter and suitable conditions, fry may appear without additional intervention.