Dogfish sharks are relatively small, but are known for relentlessly pursuing their prey. Generally they feed in packs, like dogs, which can include hundreds of the aggressive animals.

One of the most well known species of dogfish is Squalus acanthias, or the spiny dogfish. Common along the northern Atlantic and Pacific coasts, they feature a sharp spine in front of each of their dorsal fins, which are used in combination with small venom glands to wound prey. Fishermen sometimes consider spiny dogfish pests because they often steal bait and damage nets. However, spiny dogfish can be beneficial to humans, as well, since they are often utilized for liver oil and are eaten in some parts of the world.

Similar to other sharks, dogfish have placoid scales, which are spiny and covered in an enamel-like substance. Sometimes referred to as dermal denticles because of their similarity to teeth, shark scales slant towards the tail end of the shark and reduce friction against water, making swimming easier. Sharkskin is so rough that it used to be utilized to polish wood, as sandpaper is used today. When the scales are removed, however, the skin can be cured and employed as leather.