The prickly shark (Echinorhinus cookei) is one of the two species of sharks in the family Echinorhinidae (the other one is the bramble shark), found in the Pacific Ocean over continental and insular shelves and slopes, and in submarine canyons. Bottom-dwelling in nature, it generally inhabits cool waters deep, but it also frequently enters shallower water in areas such as Monterey Bay off California. This stocky, dark-colored shark grows up to long, with two small dorsal fins positioned far back on its body and no anal fin. It is characterized by a dense covering of thorn-like dermal denticles, hence its common name. Nocturnally active, the prickly shark rests during the day in deeper offshore waters and performs a diel migration to shallower inshore waters at dusk. Individual sharks have a small home range and tend to remain within a given local area. This species consumes a variety of bony and cartilaginous fishes, and cephalopods. Since it moves slowly, it may use suction to capture prey. It is aplacental viviparous, with females producing sizable litters. The prickly shark is not known to be dangerous to humans and has minimal economic value. It is caught incidentally by commercial deepwater fisheries, which are expanding and may potentially threaten its population. Thus, the International Union for Conservation of Nature (IUCN) has assessed this species as Data Deficient. Taxonomy Austrian ichthyologist Viktor Pietschmann described the prickly shark as a new species in two separate publications: a brief German account in a 1928 volume of Anzeiger der Akademie der Wissenschaften in Wien and a more detailed English account in a 1930 volume of Bernice P. Bishop Museum Bulletin. Pietschmann named the shark in honor of C. Montague Cooke Jr., a conchologist at the Bishop Museum. However, prickly sharks were continually misidentified as bramble sharks (E. brucus) and referred to as such in scientific literature until 1960, when Jack Garrick redescribed the species. Since the original holotype from Kauai, Hawaii had been lost, Garrick designated a long male from Palliser Bay, New Zealand as a new type specimen. Other common names for this species include Cook's bramble shark and spinous shark. Description The prickly shark has a flabby and cylindrical body, with the adults markedly bulkier than juveniles, and a short, moderately flattened head. The nostrils are placed far apart and preceded by small flaps of skin. The spiracles are tiny and positioned well behind the eyes,