娇鲻银汉鱼 · Delicate Blue-eye

Overview

The warm-water blue-eye Pseudomugil tenellus is best maintained socially. A line of alternating pale spots and darker gaps along the midbody becomes clearer with age. Its use of brackish habitats does not make routine marine-salt addition necessary in captivity.

Distribution & habitat

Its patchy northern Australian range extends from the Darwin area toward Cape York. Records also occur on Indonesia's Aru Islands and in Papua New Guinea's Bensbach River, with a potentially wider southern New Guinea distribution.

Coastal floodplains offer both fresh and brackish settings, including estuaries and salt marshes. Densely vegetated swamps, billabongs, and slow streams are especially characteristic. Some populations enter upper freshwater reaches, and larger fish may move into main river channels.

Aquarium setup

Provide a footprint around 75 × 30 cm. Dense plants should leave swimming room, while floating vegetation and wood soften the light. Fine moss and elevated shelter in an established aquarium may help retain offspring.

Keep water oxygenated, moderately circulated, and regularly renewed. Avoid immature systems. Warm conditions suit it, but isolated high field readings are not constant aquarium targets. Brackish-origin fish can live and breed in freshwater, so salt is optional rather than obligatory.

Diet & feeding

It primarily takes floating or suspended plankton, algae, and small invertebrates, with proportions changing seasonally. Offer suitable live water fleas, brine-shrimp nauplii, and microworms alongside small floating dry foods. Dry products should preferably include plant or algal material.

Behaviour & compatibility

Peaceful fishes of comparable size and matching requirements can be suitable companions. Keep at least eight to ten conspecifics, preferably more where space permits. Company encourages confidence and male display behavior.

Sexual dimorphism

Males become larger, brighter, and more strongly patterned, with extended unpaired fins at maturity.

Breeding

It scatters eggs without parental care and may consume eggs and fry. Natural reproduction follows the onset of the wet season. During warm periods, daytime spawning produces small daily batches attached by threads, and males can mate with several females.

A male and two or three females can be isolated with sponge filtration and mops or moss, checking several times daily for eggs to incubate separately. Alternatively, a larger mature planted colony allows fewer young to survive with less intervention. Elevated moss or trailing roots protect surface-oriented fry and supplement their early microscopic food supply.

Hatching takes roughly ten days. Microscopic food such as paramecia may be needed for up to about five days before introducing brine-shrimp nauplii, microworms, or suitable powdered foods. Feed small meals at least twice daily, clear leftovers, and change small amounts of water regularly.

Notes

The midbody spot row is a useful identification feature. Overall appearance varies with locality, reproductive condition, and water chemistry. Age-related fertility decline described for the genus should not be converted into a precise lifespan limit for this species.