The rough longnose shark, Deania hystricosa, is a little-known deepwater dogfish.Rough longnose dogfish have an extremely long snout, no anal fin, small grooved dorsal spines, and rough pitchfork-shaped dermal denticles. The first dorsal fin is long and narrow. Maximum length is 109 cm.Found in the Eastern Atlantic around Madeira and in the western Pacific around southern Japan. This shark is rarely seen but lives between 600 and 1,000 m.