Gasterosteiformes

The type series was collected from a blackwater stream in Toh Daeng Peat swamp forest with the fish found in slow-moving or standing habitats among submerged shoreline roots and leaf litter. In the Tapi River floodplain it was collected from stagnant waters, one of which was an oxbow lake approximately 200 m long and 30 m across at its widest point, surrounded by 'freshwater scrub and swamp trees'. The substrate was composed of mud, woody structures including fallen twigs and branches, and decomposing plant material.

This species is rare in the aquarium hobby though its name is often misapplied to the closely-related I. crocodilus. It can be told apart from congeners by the following characters: dorsal and anal fins without dark markings, with a light brown bar in breeding males; ventral surface light brown; throat white, occasionally with a few brown spots; ridges of head bones weakly serrated or not serrated, depending on the bone. The family Indostomidae currently contains just a single genus with three species of which I. paradoxus is the type. It was raised alongside both family...