[4] It is an elongated marine catfish that reaches up to 28 in (70 cm) in length and 12 lb (5.5 kg) in weight.

[4][5] Hardhead catfish are also found in brackish estuaries and river mouths where the bottom is sandy or muddy,[6] but only occasionally enter freshwater.

[8] These barbels help the catfish find crabs, fish, and shrimp in the muddy or sandy bays where they live.

The head is slightly flattened and conceals a hard plate between the eyes and dorsal fin.

Its diet primarily consists of algae, seagrasses, cnidarians, sea cucumbers, gastropods, polychaetes, shrimp, and crabs.

Younger hardhead catfish tend to eat small crustaceans, like amphipods, shrimp, blue crabs, mollusks, and annelids.

[10] Juveniles that are still under the protection of the male mouthbrooder feed predominately on planktonic crustaceans close by to the mouth of the parent.

Under controlled conditions of photoperiod, temperature, and water quality, hardhead catfish display nonrandom oscillations in angular orientation of locomotive activity.

The presence of this seasonal behavior indicates that a circadian neural mechanism may exist in hardhead catfish.

[12] Furthermore, hardhead catfish are the first indicator that Osteichthyes possibly could use directional hearing to detect obstacles.

[13] Some evidence indicates sound production in hardhead catfish is differentiated both mechanistically and contextually.

Some argue that hardhead catfish use an unrefined form of sonar as a means of echolocation, which also implies some directional hearing ability.

[8] Oral incubations continue through the yolk-sac larval state, for a total length around 8–11 weeks.

[8] The offspring are roughly 6–8 cm long and slowly adapt to adult behavior, such as opportunistic bottom-feeding and scavenging.

[8] The parental male can choose to carry the young after they have hatched until they are larger and capable of surviving on their own.

Though mouthbrooding requires more energy by the male, the chance of his young surviving to adulthood is greater, thus reproducing and continuing his genes; the eggs are not defenseless while in their father's mouth.

[18] Mouthbrooding by males counters the relatively low fecundity of females, which only have 20–65 eggs per spawning episode.