Stream habitat
Adults inhabit clear, free-flowing streams. They often stay near cover and may rest on logs, stones, gravel or leaf debris in slower sections, even where nearby water is flowing strongly. Sandy stream bottoms are also reported. These local refuges help explain why it can occur in a river without occupying its fastest current.
Sources: Gobiomorus dormitor species summary
Feeding
FishBase describes a carnivorous fish that uses subdued movement and camouflaged coloration. Larger aquatic invertebrates and other fishes are reported prey. A still fish resting on the substrate is therefore consistent with its normal behavior, rather than evidence that it is inactive throughout the day.
Sources: Gobiomorus dormitor species summary
