They have two large dorsal fins, each with a sharp spine, and with the first fin placed far forward above the head. Even more so than their relatives, the dogfishes, they have rough and prickly skin.
The description highlights the presence of two large dorsal fins, each with a sharp spine, positioned in front of the head. The text emphasizes the rough and prickly nature of their skin, which is more pronounced than that of their dogfish relatives.