Tiny grey deepwater hump-back looking shark with two dorsal spines
The Prickly dogfish (Oxynotus bruniensis) is a poorly known species of shark belonging to the order of Dogfish sharks in the family Oxynotidae, inhabiting temperate Australian and New Zealand waters. It is brown to grey, with a very thick body, rough skin and what looks like a hump on its back. It has two large sail-like dorsal fins.
Family: Oxynotidae – Roughsharks
Common Name– Dogfish Sharks
Common Name– Roughsharks
Status: IUCN Red List DATA DEFICIENT
Average Size and Length: The Prickly dogfish reaches a length of 2-2.5 feet, but possibly 3 feet.
Teeth and Jaw: The mouth of the Prickly dogfish is relatively small and transverse and surrounded by deep furrows coming from the mouth corners. The lips are thick and have papillae. There are 12–19 upper and 11–13 lower tooth rows. The upper teeth are small with narrow upright cusps, while the lower teeth are large with broad knife-like triangular cusps.
Head: Its head of the Prickly dogfish is slightly flattened, with a short, rounded snout. The nostrils are large and closely spaced. The eyes are immediately followed by small round spiracles.
Denticles: It has extremely rough skin. The dermal denticles are large with narrow, knife-like crowns.
Tail: The caudal fin is broad and high, with a ventral notch near the tip of the upper lobe.
Demographic, Distribution, Habitat, Environment and Range: The Prickly dogfish can be found in temperate waters off Australia from Crowdy Head in New South Wales, around the southern coast of Tasmania, to as far as Esperance in Western Australia. It also can be found off New Zealand and adjacent islands, and over the submarine Chatham Rise, Challenger Plateau, and Campbell Plateau. It prefers to stay near the sea floor over outer continental and insular shelves and upper slopes at a depth range of 151 to 3,501 feet but is typically found between 1,148 and 2,133 feet.
Diet: The Prickly dogfish is thought to eat small benthic organisms.
Aesthetic Identification: It is brown to grey becoming translucent at the trailing margins of the pectoral and pelvic fins, with a very thick and stout body with 5 pairs of gill slits, rough skin and what looks like a high-arched hump on its back. The body looks triangular in cross-section. The two dorsal fins are very tall with triangular, sail-like apexes; the anterior portion of each fin is fleshy, in which is embedded a spine with only the tip exposed. The first dorsal fin spine is tilted forward. The origin of the first dorsal fin lies over the gill slits, ahead of the pectoral fins. The second dorsal fin is smaller than the first, and the distance between it and the first dorsal fin is less than the length of its base. There are a pair of thick ridges running along the abdomen between the pectoral and pelvic fins, which are smaller than the second dorsal fin. There is no anal fin.
Biology and Reproduction: The liver of the Prickly dogfish is large and oily, allowing it to remain neutrally buoyant easily.
The Prickly dogfish is ovoviviparous, having litters of between 1-7 pups. Newborn pups measure about 9.4 inches long. Males and females attain sexual maturity around 22–24 inches and 26 inches long.
Behavioral Traits, Sensing and Intelligence: Unknown.
Speed: Thought to be a slow-moving shark.
Prickly Dogfish Recorded Attacks on Humans: Not a threat to humans.