珍珠燕子 · Spotted Blue-eye

Overview

The spotted fins of Pseudomugil gertrudae make it distinctive, but its timid nature makes feeding competition a practical concern. Keep at least eight to ten in a mature, densely planted aquarium with stable conditions rather than a busy general community.

Distribution & habitat

Records extend across northern Australia, southern Papua New Guinea, and Indonesia's Aru Islands. Wild populations are often isolated and differ in color, size, and fin form. Locality information should be retained and breeding lines kept separate.

It favors shallow vegetated margins of slow or standing water, including streams, lakes, billabongs, and swamps. Plants, roots, branches, and litter provide cover. Habitats range from clear water to strongly acidic, nutrient-poor blackwater, often with vegetation at the surface.

Aquarium setup

Provide a base around 45 × 30 cm. Dense planting, floating cover, and branches soften the light. Fine moss and high-level shelter in an established aquarium help retain young.

Maintain oxygenation and moderate circulation, avoiding immature systems. The established maintenance range concerns the common ornamental strain. Fish of specific wild provenance, especially blackwater origin, may need different conditions and should not automatically receive the same treatment.

Diet & feeding

It primarily takes floating or suspended plankton and small invertebrates. Suitable live foods include water fleas, brine-shrimp nauplii, and microworms. Finely crushed floating dry food can supplement the menu.

Behaviour & compatibility

A species aquarium simplifies care. Carefully selected small quiet fishes or suitable freshwater shrimp are alternatives when requirements match. Maintain at least eight to ten conspecifics, preferably more where space allows, to reduce nervousness and encourage male displays.

Sexual dimorphism

Males show stronger color and pattern and develop extended unpaired fins at maturity.

Breeding

Eggs are scattered without care, and adults may eat eggs and offspring. Natural reproduction follows the wet season; stable warmth can sustain aquarium spawning. Activity occurs by day, often peaking around midday. Females deposit small batches over several days, attaching eggs by threads, and males may mate with several females.

One method uses a male and two or three females with sponge filtration and mops or moss. Check repeatedly during the day and incubate collected eggs separately. A larger mature planted colony can instead produce fewer surviving young with less intervention. Elevated moss and trailing roots shelter surface-oriented fry while resident microorganisms supply early food.

Incubation lasts roughly ten days. Fry may need microscopic food such as paramecia for up to about five days before taking brine-shrimp nauplii or microworms. Appropriate powdered diets are another option. Feed small portions at least twice daily, remove waste, and change small amounts of water regularly.

Notes

Spots in the dorsal, anal, and caudal fins are useful clues but are not unique to this species. Ornamental stock and locality-tracked lines should be distinguished; a photograph of the pattern alone cannot establish provenance.