Whiskery Shark

The whiskery shark has a moderately stout build, with an almost "humpbacked" appearance. The short snout is rounded or wedge-shaped when viewed from above. This species is the only houndshark in which the flaps of skin preceding the nostrils are elongated into thin barbels. The horizontally oval eyes are placed high on the head and are equipped with rudimentary nictitating membranes (protective third eyelids). Beneath the eye is a prominent ridge, and behind it is a tiny spiracle. The mouth forms a short, wide arch, and bears somewhat long furrows at the corners. Tooth rows number 24–32 in the upper and 36–42 in the lower jaw. Each upper tooth has an angled, knife-like main cusp with smaller cusplets on the trailing side, while each lower tooth has a single upright cusp. Five pairs of gill slits are seen. The first dorsal fin is rather large and positioned closer to the pectoral than the pelvic fins, though its origin lies posterior to the pectoral fin rear tips. The second dorsal fin roughly equals the first in size and is positioned slightly ahead of the anal fin, which is much smaller than either dorsal fin. The caudal fin has a short lower lobe and a deep ventral notch near the tip of the upper lobe. …

Endemic to Australia, the whiskery shark inhabits temperate continental shelf waters from the North West Cape in Western Australia to Wynyard in Tasmania. It is most common in the southwestern portion of its range between Kalbarri and Albany, and is rare off Victoria and Tasmania. Its range seems to encompass a single population. This species is found close to the bottom at depths to 220 m (720 ft). It favors rocky areas and kelp beds.

The whiskery shark is an active and highly specialized predator, feeding almost exclusively on octopuses. Other cephalopods, bony fishes, small rock lobsters, spoon worms, and seagrass have also been found amongst its stomach contents. A known parasite of this species is the tapeworm Calliobothrium pritchardae. Like other houndsharks, the whiskery shark is viviparous; the developing embryos are sustained by yolk and probably also maternally produced histotroph. Males can mate every year, while females have a biennial reproductive cycle. Mating takes place in August and September; females store sperm until late January to early April of the following year, when the ova are ready to be ovulated into the uterus. After a 7– to 9-month-long gestation period, litters of four to 28 (average 19) pups are born between August and October. The litter size increases with the size of the female. The newborns measure 22–27 cm (8.7–10.6 in) long. Juvenile whiskery sharks are rarely caught by commercial fishers, suggesting that nursery areas may be found in deeper water or other unfished habitats. Pups double to triple in size in the first 15–17 months of life, and continue to grow rapidly until they are 3–4 years old. Sexual maturity is attained at a length of 1.1–1.3 m (3.6–4.3 ft) for both sexes, corresponding to around five years of age for males and seven years of age for females. …