Opistognathus randalli is a slender, large-mouthed jawfish with a pearl-gray to pale body crossed by seven to ten yellow-orange bands. The fins carry yellowish tones edged in pale blue, the head is gray-brown and frequently black across the top, and the upper iris glows golden. A dark stripe inside the upper jaw serves as a diagnostic field mark, and females typically show a small black spot between the second and third dorsal spines, making this the only Indo-Pacific jawfish reported with a sexually dichromatic dorsal fin. The species ranges from Bali east to the Philippines and north to Taiwan, with records from Indonesia and eastern Borneo, where it occupies sand and rubble flats near reefs between roughly 5 and 32 meters. Aquarium specimens mature around 4 inches.

Adult housing begins at 30 gallons, though a 40- to 55-gallon footprint gives the fish far more room to establish a functional burrow zone. Substrate matters more than tank height: provide at least 3 to 4 inches of mixed-grain sand supplemented with shell fragments, coral rubble, and small stones that the jawfish can carry and wedge into place to reinforce its tunnel walls. Rockwork near the intended burrow entrance must be placed directly on the bottom and seated securely, since ongoing excavation beneath an unstable structure invites collapse. A mature, stable reef system suits this species best, and no unusual water chemistry beyond steady marine reef parameters has been reported.

A secure, gap-free lid is not optional. Startled jawfish launch themselves upward and will exit through any opening left around overflows, return plumbing, or feeding gaps, so screen every gap before the fish is introduced. Care requirements sit at a moderate level largely because of these husbandry details rather than any difficulty with feeding once the fish has settled.