Blotchy Swell Shark

The blotchy swell shark or Japanese swellshark (Cephaloscyllium umbratile) is a common species of catshark, family Scyliorhinidae, found at depths of 90–200 m (300–660 ft) in the northwestern Pacific Ocean from Japan to Taiwan. It is benthic in nature and favors rocky reefs. Reaching 1.4 m (4.6 ft) in length, this thick-bodied shark has a broad head, large mouth, and two unequally-sized dorsal fins positioned far back past the pelvic fins. It can be identified by its dorsal coloration, consisting of seven brown "saddles" and extensive darker mottling on a light tan background. This species has often been confounded with the draughtsboard shark (C. isabellum) and the Sarawak pygmy swellshark (C. sarawakensis) in scientific literature.

Voracious and opportunistic in feeding habits, the blotchy swell shark is known to consume numerous types of fishes and invertebrates, including an unusually high diversity of cartilaginous fishes. Like other Cephaloscyllium species, it is capable of rapidly inflating its body as a defense against predators. This species is oviparous, with females laying encapsulated eggs two at a time. There is no well-defined breeding season and reproduction occurs year-round. The eggs hatch after approximately one year. The blotchy swell shark is harmless and fares well in captivity. It is caught as bycatch in commercial bottom trawls, though its population does not seem to have suffered from fishing activity. The International Union for Conservation of Nature (IUCN) presently lacks sufficient information to assess its conservation status.