Oryzias asinua · Asinua Ricefish

Overview

A slender ricefish from Sulawesi, Oryzias asinua has orange olfactory tissue in both sexes. This feature helps distinguish it from closely similar fishes, while aquarium-specific experience remains limited.

Distribution & habitat

Known records are restricted to the Asinua River in Southeast Sulawesi, Indonesia. Clear water ranged from slow to fast over mud, sand, and gravel with emergent grasses. Collections came from the margins and small floodplain pools rather than exclusively from the main current.

Aquarium setup

General ricefish practice suggests dark substrate, dense plants, and open swimming areas, with roots, wood, and floating vegetation providing cover. Such arrangements commonly improve display and give juveniles refuge. This is guidance for the genus rather than a demonstrated breeding protocol for this species.

Sexual dimorphism

Adult males are slimmer and more colorful, with longer dorsal and anal fins. Their genital papilla is a short conical tube, whereas that of females is divided into two lobes.

Notes

Similar relatives include Oryzias wolasi and Oryzias woworae. Nasal coloration and the comparatively slender body help separate them; blue sheen and orange-red fin margins alone do not establish identity.