Taxonomy & naming
Kottelat described the species in 1990 from the western basin of Lake Towuti, near Tanjung Posombuwang. It is one of three or four Oryzias endemic to the lake, which also holds O. marmoratus, and it belongs to the group of Sulawesi ricefishes that live in the Malili lakes.
Morphology
A ricefish larger than most Oryzias; FishBase gives a maximum of 2.5 in TL.
Habitat
Lake Towuti, Central Sulawesi, a large, deep, clear tectonic lake with alkaline water. FishBase says adults occur along gently sloping shores with large boulders on sand and pebble bottoms, below 5 ft depth and in small groups of 2 to 20. It gives a pH range of 7.5 to 8.5 and a temperature range of 22 to 25 C.
Feeding
Takes small invertebrates and plankton.
Mating
Courtship has not been described.
Breeding
FishBase reports it as a non-annual breeder. Details of spawning and incubation have not been published.
In the aquarium
Rarely kept. A group would need a planted tank with a lid, water in the pH 7.5 to 8.5 range and tropical temperatures, with small live foods. Do not mix with larger fish.
Conservation
The IUCN Red List classes Oryzias profundicola as Near Threatened, meaning it is close to qualifying for a threatened category. The Malili lakes face introduced fishes, mining and catchment change.