Longnose Pygmy Shark

The largest known specimen of the longnose pygmy shark is a male 37 cm (15 in) long. Its body is slender and moderately compressed from side to side. The long, bulbous snout comprises about half the head length, and comes to a blunt, conical tip. The eyes are large, lack nictitating membranes (protective third eyelids), and are followed by large spiracles. The nostrils are long and angled, with a very short flap of skin on their anterior rims. The mouth is transverse and surrounded by thin, smooth lips. The upper teeth number 22 rows and are small and upright with a single narrow cusp. The lower teeth number 23 rows and are much larger, broader, and knife-like, and interlock to form a continuous cutting surface. The five pairs of gill slits are tiny and of uniform width. The two dorsal fins lack spines. The first dorsal originates over the pectoral fin bases; the second dorsal is slightly larger than the first but is about equal in base length, and originates over the middle of the pelvic fin bases. The pectoral fins are short and somewhat paddle-like. There is no anal fin. The caudal fin is broad, with a well-developed lower lobe and a deep ventral notch near the tip of the upper lobe. The small dermal denticles have sharp wedge-shaped crowns bearing median ridges, and are placed on stalks (pedicels). …

The longnose pygmy shark has been caught in the western Indian Ocean off eastern KwaZulu-Natal, in the southeastern Atlantic Ocean near the Walvis Ridge, and in the southwestern Pacific Ocean off Chile. These records suggest that it may have a circumglobal distribution in the Southern Hemisphere, inhabiting subantarctic waters and cold ocean currents, including the Benguela and the Humboldt. This species occurs in the open ocean between the surface and a depth of 502 m (1,647 ft), in water 830–4,000 m (2,720–13,120 ft) deep.

The natural history of the longnose pygmy shark is poorly known. It probably feeds on pelagic fishes and invertebrates, and is presumably aplacental viviparous with a small litter size like other members of its family. The 13 cm (5.1 in) long type specimen had an umbilical scar, suggesting that it was close to the birth size. Males and females attain sexual maturity at under 36 and 33 cm (14 and 13 in) long respectively.