Growing up to 40 centimeters in length, the oblique-banded beard croaker features a deep, laterally compressed body with a silvery-gray base color adorned by 5–6 dark, oblique bands that run from the dorsal fin to the ventral side, creating a bold, eye-catching pattern. Its most notable feature is the pair of small, bristle-like barbels near the corners of its mouth, which aid in detecting benthic prey such as crustaceans, mollusks, and small fish. The dorsal fin is divided into two parts: a spiny anterior section and a soft-rayed posterior section, while the caudal fin is slightly forked, enabling agile movement over sandy or rocky seabeds.

Primarily a demersal species, Hapalogenys mucronatus inhabits shallow coastal areas, including rocky reefs, estuaries, and the vicinity of jetties, at depths ranging from 10 to 60 meters. It is a solitary or small-group feeder, active during both day and night, using its barbels to probe the substrate for food. During the breeding season, typically in late spring to early summer, adults migrate to nearshore waters to spawn, releasing pelagic eggs that develop in the water column. Juveniles often seek shelter in seagrass beds or among artificial structures, gradually moving to deeper habitats as they mature.

Highly prized in regional cuisines for its tender, flavorful flesh, the oblique-banded beard croaker is a key species in commercial and recreational fisheries. However, its populations have declined due to overfishing, habitat degradation from coastal development, and pollution. Conservation efforts, such as the establishment of marine protected areas, seasonal fishing bans, and aquaculture initiatives, aim to sustainably manage its stocks. As a vital component of coastal marine ecosystems, Hapalogenys mucronatus underscores the need for balanced stewardship of marine resources to ensure its survival and the health of its habitat.