horizontally oval, equipped with rudimentary nictitating membranes (protective third eyelids), and lack strong ridges underneath. Tiny spiracles are located behind the eyes. The mouth is large, wide, and arched, with well-developed furrows at the corners. The teeth have a central cusp and 1–2 pairs of smaller lateral cusplets. There are five pairs of gill slits. The two dorsal fins are blunt-tipped and similar in size; the first is positioned over the rear of the pelvic fins and the second over the rear of the anal fin. The pectoral fins are large and broad with rounded corners, while the pelvic and anal fins are elongated and more angular. The anal fin base is close to the pelvic and caudal fins and measures 14–17% of the total length, much greater than the distance between the dorsal fins. The caudal peduncle is compressed from side to side and leads to a low caudal fin with a small lower lobe and a ventral notch near the tip of the upper lobe. The dermal denticles are small and overlapping, each with three-toothed crown that bears a median ridge. There is a crest of enlarged saw-like denticles along the dorsal edge of the caudal fin. This species is dusky above and light below. There are typically 11 or fewer dark gray or brown saddles and/or blotches outlined in white along the back and tail. The pattern tends to fade with age, and some individuals are uniformly colored. The interior of the mouth is black. Biology and ecology Small bony fishes, including lanternfishes, hakes, grenadiers, rockfishes and lightfishes, comprise the bulk of the African sawtail catshark's diet. Squid and crustaceans may also be consumed. A known predator of this species is the southern African frilled shark (Chlamydoselachus africana). Unlike other members of its genus, the African sawtail catshark is aplacental viviparous, with females retaining eggs internally until they hatch. There is apparently no defined breeding season, and mating and birthing occur throughout the year. Adult females have two functional uteruses and produce litters of up to 12 young; litter size increases with female size. The developing embryos are initially sustained an external yolk sac, and emerge from the egg at between long. Pigmentation begins to develop at an embryonic length of . At around long, the embryos have well-developed external gills, which largely disappear by the time they are long. Near-term fetuses weigh over twice as much