Squalus acanthias is one of the most common shark species in the world. It is equally comfortable in both the Black Sea and the Barents Sea. It prefers to live close to shore at shallow depths. This is a small shark, whose length can reach just under 1.5 m, and weigh up to 12 kg. A streamlined body, covered with tough grayish brown scales, makes the Spiny dogfish an excellent swimmer. Between the front and rear fins, this shark has spines that almost reach the size of the fins.