The blotchy swell shark is a small shark with a maximum length of 3.9 feet.

The blotchy swell shark has a grayish-brown mottled body that allows it to blend effectively with rocky seabeds.

The blotchy swell shark is found in the northwestern Pacific ocean, particularly off the coasts of Japan, China, and Taiwan.

The blotchy swell shark inhabits rocky bottoms, reefs, and coastal areas of the continental shelf. It is generally found at depths ranging from 164 to 1,312 feet, but it can occasionally be observed closer to the surface or at greater depths.

The blotchy swell shark is a primarily nocturnal species that often remains motionless during the day or hides in rocky crevices before going out to hunt at night. Its mottled coloration provides excellent camouflage on the seabed.

The blotchy swell shark is an opportunistic predator that feeds mainly on small bottom-dwelling animals. Active mostly at night, it hunts discreetly in rocky areas and reefs where it finds a wide variety of prey. Its diet consists mainly of small bony fish, cephalopods such as squids and cuttlefish, as well as crustaceans like shrimp and crabs.

Thanks to its wide mouth and teeth adapted for capturing prey, the blotchy swell shark can swallow animals relatively large compared to its body size.

The blotchy swell shark is an oviparous species. At birth, juveniles typically measure between 7.9 and 8.7 inches in length and are immediately independent.

The blotchy swell shark is a species of shark known for its remarkable ability to inflate its body when threatened.