曼谷青鮰 · Mekong Ricefish

Overview

A miniature freshwater ricefish of the Mekong basin, Oryzias mekongensis has vivid orange-red tail margins in males. Its small size limits community choices, while a group with calm tiny companions encourages confident behavior.

Distribution & habitat

It is endemic to Mekong drainages in northeastern Thailand, Laos, and Cambodia. Only freshwater habitats are known, especially clear swamps, ditches, canals, and ponds with dense fine vegetation. Some occupied waters may be acidic.

Aquarium setup

A group requires at least the suggested 40 by 20 cm footprint. Dark substrate, wood, dense plants, surface cover, and open areas support color and provide some protection for fry.

Diet & feeding

It feeds on tiny insects, worms, crustaceans, and zooplankton. Use appropriately small dry foods together with daily live or frozen invertebrates.

Behaviour & compatibility

Eight or more give the best group display. Small peaceful fish or suitable freshwater shrimp sharing the conditions are possible companions. Keep a single species for breeding to avoid hybridization.

Sexual dimorphism

Males are slimmer and show stronger orange-red bands on both tail margins. Females retain much fainter bands. The genital papilla is tubular in males and bilobed in females.

Breeding

Well-conditioned females may spawn every few days or daily, generally in the morning. Males darken and defend small temporary areas. Eggs are released and fertilized together, briefly carried externally, then attached to fine plants or spawning mops.

Hatching usually takes one to three weeks, depending on temperature. Adults often ignore eggs but eat swimming young. Dense plants may preserve a few, or eggs and fry can be reared separately in parental water. Start with microworms and Artemia nauplii, separating very different-sized juveniles to prevent cannibalism.