cusps, while the lower teeth are broad and comb-shaped (except for a symmetrical symphysial tooth). Unlike most other sharks, there are seven pairs of gill slits that extend onto the throat. A single small dorsal fin is located behind the pelvic fins, with a straight front margin, narrowly rounded tip, and concave rear margin. The pectoral fins are small with a weakly convex outer margin. The anal fin is small with nearly straight margins. The caudal peduncle is long, and the distance between the dorsal fin origin and the caudal fin is more than twice the dorsal fin base. The closely overlapping dermal denticles are very thin and transparent; each is longer than it is broad, bearing a distinct median ridge and two lateral ridges ending in marginal teeth. The coloration is brownish gray to olive above and lighter below; some individuals have dark blotches on the body or light posterior fin margins. Juveniles have dark blotches on the flank and dark tips on the dorsal fin and upper caudal lobe. Biology and ecology Despite its relatively small size, the sharpnose sevengill shark is considered a top predator in the ecosystem it inhabits. At the Great Meteor Seamount in the eastern Atlantic, this species feeds primarily on teleosts and cephalopods, and to a lesser extent on small cartilaginous fishes. Off Tunisia, crustaceans are the second-most common prey taken after teleosts. Off Australia, this species consumes mostly teleosts, with smaller individuals taking mainly Lepidorhynchus denticulatus and larger individuals taking increasing numbers of snake mackerels and cutlassfishes. It is a strong-swimming species, with feeding and activity level increasing at night. This species may be preyed upon by larger sharks. Known parasites of the sharpnose sevengill shark include nematodes in the genera Anisakis and Contracaecum, and the cestode Crossobothrium dohrnii. Reproduction is ovoviviparous, with no apparent reproductive season. The females give birth to litters of 9–20 pups; the newborns measure about long. Males mature at long and females at . The onset of sexual maturation in males may be marked by the formation of mucus on the tips of the claspers. Relationship to humans The sharpnose sevengill shark is reasonably small and is located in generally deep water, and these characteristics classify this shark as harmless to humans. Small to moderate numbers of sharpnose sevengill sharks are captured as bycatch in certain deepwater commercial fisheries on longlines or in trawls. They are used