The slender smooth-hound or gollumshark (Gollum attenuatus) is a species of ground shark in the family Pseudotriakidae. It is endemic to the waters around New Zealand, where it is usually found close to the bottom over the continental slope at depths of 300–600 m (980–1,970 ft). An extremely slim, plain brownish shark reaching 1.1 m (3.6 ft) in length, the slender smooth-hound can be identified by its broad, flattened head with a long, distinctively bell-shaped snout. Its mouth is angular with short furrows at the corners, and contains a very high number of tooth rows in both jaws. Its two dorsal fins are roughly equal in size.