Spotted Gully Shark

The sharptooth houndshark is a stout-bodied species with a short, thick, and blunt snout. The nostrils are widely spaced and preceded by lobe-like flaps of skin that do not reach the mouth. The horizontally oval eyes have ridges underneath and are equipped with nictitating membranes. The large mouth bears long, deep furrows at the corners, with those on the lower jaw almost meeting in the middle. The teeth are small and tightly packed to form pavement-like surfaces. Each tooth has a rounded, molar-like base that rises to a sharp, upright central cusp; rarely, a pair of barely developed lateral cusplets may also be present. Five pairs of gill slits are found. The fins are distinctively large and rounded at the tips. The pectoral fins of adults are broad and falcate (sickle-shaped). The dorsal fins have nearly vertical trailing margins, with the first originating over the pectoral fin rear tips. The second dorsal fin is about three-quarters as high as the first. The anal fin is much smaller than the second dorsal fin and originates well behind it. The short, thick caudal peduncle lacks notches at the caudal fin origins. The caudal fin has a small but well-defined lower lobe and a longer upper lobe with a ventral notch near the tip. The skin is often loose. This species is dark gray to bronze above and white below. …

The range of the sharptooth houndshark is limited to the coastal waters of southern Africa, from southern Angola to the Eastern Cape (or rarely KwaZulu-Natal) in South Africa. This locally common species inhabits sandy habitats such as bays; it can be found from the surf zone to a depth of 50 m (160 ft), but the majority are found no deeper than 10 m (33 ft). It generally swims just barely above the bottom, favoring flat areas near rocky reefs or gullies, and seldom rises into open water.

The sharptooth houndshark is a highly active species, though it can sometimes be found resting inside rocky crevices. It mainly hunts at night and has been known to pursue prey almost onto the shore. The pointed cusps of its teeth allow it to grasp slippery prey, while their broad bases allow it to crush hard-shelled prey. This shark feeds on a variety of crustaceans (crabs, slipper lobsters, and spiny lobsters), bony fishes (including morwongs, sea catfishes, drums, and porgies), and cephalopods (in particular Octopus vulgaris). Sharks and rays (including catsharks and guitarfishes) and their egg capsules are a minor food source for larger individuals. Off South Africa, the most important prey species is the crab Plagusia chabrus. Its dietary composition changes with age; young sharks under 1.0 m (3.3 ft) long subsist almost completely on crabs, while larger sharks consume more bony fishes and cephalopods, as well as a greater variety of prey overall. This shark has been observed deviating from its nocturnal habits to feed on chokka squid (Loligo reynaudii) during their mass spawnings. The broadnose sevengill shark (Notorynchus cepedianus) is known to prey on this species. During the summer, the sharptooth houndshark forms groups in shallow water. …