Snout moderately long, broadly parabolic, preoral snout equal or greater than mouth width but shorter than distance from mouth to pectoral origins; bladelike unicuspidate teeth in upper and lower jaws, with lowers much larger than uppers. Two dorsal fins with large spines; first dorsal fin very low and long; second dorsal moderately large, nearly as high or slightly higher than first, with base about 1/2 to 3/5 length of first dorsal base, and spine origin over inner margins of pelvic fins; distance from first dorsal insertion to origin of second dorsal spine about as long as tip of snout to pectoral midbases in adults and subadults; caudal fin with a shallowly concave to weakly notched posterior margin in adults and subadults. No anal fin. Lateral trunk denticles not overlapping each other, blocklike, with crowns sessile on bases and without pedicels, crowns elongated and longitudinally rhomboidal in adults, with a strong main cusp and no lateral cusps on their posterior edges in adults.
habitats
Adults reach at least 160 cm; adult males from 72 to 128 cm and females from 88 to 144 cm; size at birth about 36 cm. A large deepwater dogfish of the outer continental shelves and upper slopes at depths between 300 to 1400 m. Ovoviviparous, number of you
Distribution
Northeast off Taiwan; Eastern Atlantic; Western Indian Ocean; Western Central Pacific.