Taxonomy & naming
Mokodongan, Tanaka and Yamahira described the species in 2014 from Lake Tiu, a small lake in the Morowali region of Central Sulawesi. It belongs to the Sulawesi radiation of Oryzias, and the species name honours Soeroto, a worker on Sulawesi ricefishes.
Morphology
A small ricefish; FishBase gives a maximum of 1 in SL.
Habitat
Lake Tiu, a small lake in Central Sulawesi. The species is not known from elsewhere. FishBase describes a lake surrounded by trees and mountains, with a muddy bed and calm, transparent water stained dark by decaying vegetation. Juveniles and young fish live in shallow, densely vegetated water.
Feeding
Takes small invertebrates and plankton.
Mating
Courtship has not been described in detail.
Breeding
From aquarium observations reported by FishBase, females carry eggs at the genital pore for several hours and then deposit them onto submerged yarn. Clutch size and incubation time have not been published.
In the aquarium
Rare in culture. A group needs a planted tank with a lid and tropical temperatures, with small live foods. The lake water is dark, calm and stained by plant matter, which is a better guide to its needs than a hard, bright setup.
Conservation
The IUCN Red List classes Oryzias soerotoi as Critically Endangered, meaning it faces an extremely high risk of extinction in the wild. As a single-lake endemic it is exposed to introduced fishes and shoreline change.