Saddled Swellshark

The saddled swellshark reaches a maximum known length of 74 cm (29 in). It has a moderately stocky body and a short, variably wide, and strongly flattened head. The snout is broadly rounded, with the nostrils preceded by laterally expanded flaps of skin that do not reach the large mouth. The slit-like eyes are positioned high on the head and followed by tiny spiracles. The tooth rows number 68–82 in the upper jaw and 68–80 in the lower jaw. The very small teeth have three cusps, with the central one the longest and sometimes 1–2 additional lateral cusplets. In females the central cusp is smaller than in males. There are no furrows at the corners of the mouth, and the upper teeth are exposed when the mouth is closed. The fourth and fifth gill slits lie over the pectoral fin bases and are shorter than the first three. The pectoral fins are large and broad, with rounded margins. The first dorsal fin is fairly angular and originates over the middle of the pelvic fin bases. The second dorsal fin is much smaller and lower than the first, originating behind the anal fin origin. The pelvic fins are small, with elongate, relatively short claspers in males. The anal fin is substantially larger and deeper than the second dorsal fin. The caudal fin is deep, with a distinct lower lobe and a strong ventral notch near the tip of the upper lobe. …

The saddled swellshark is found off the eastern coast of Australia, as far north as Rockingham Bay in Queensland and as far south as Tathra in New South Wales, and perhaps also the Britannia Seamount near Brisbane. It is a bottom-dwelling species that inhabits the outer continental shelf and upper continental slope at a depth of 115–605 m (377–1,985 ft).

Like other members of its genus, the variegated swellshark can inflate itself with water or air as a defensive measure. This species is oviparous, with its eggs contained in smooth, brownish capsules about 7 cm (2.8 in) long. The egg capsule is thick and rounded, with flanged lateral margins and a pair of horns at each end, which support very long, coiled tendrils. The smallest known free-swimming specimen measured 17 cm (6.7 in) long; males mature sexually at a length of 55–60 cm (22–24 in).