A non-migratory species, I. signifer can be observed in close association with coral reefs at depths of from 10 to 70 metres (33 to 230 ft).

[4] This species was first formally described in 1903 by the American ichthyologists David Starr Jordan and Barton Warren Evermann with the type locality given as Oahu in Hawaii.

[4] Like other scorpionfishes, I. signifer is a benthic organism, remaining in close proximity to the seafloor and coral reef for shelter, as well as camouflage from predators and prey.

The reddish-orange to white coloring covering most of the fish's body serves as camouflage along the Indo-pacific coral reefs where it resides.

[8] The decoy scorpionfish has been noted on multiple accounts to display a unique prey-luring mechanism, involving the movement of its dorsal fin.

The fish-like shape of the fin is emphasized by the more subtle movement between the first and second dorsal spines, which continually move closer and then further apart, mimicking the opening and closing of a fish's mouth.