They live in deep waters in the Atlantic and western Pacific Oceans.

Rough sharks are small to medium in size, ranging from 49 to 150 cm (1.61 to 4.92 ft) in adult body length, depending on species.

Their bodies are compressed, giving them a triangular cross-section.

Even more so than their relatives, the dogfishes, they have rough and prickly skin.

Unusually among sharks, they also possess a luminous organ.