Author: Günther, 1870
A white-spotted Mustelus with a broad internarial space, short head, low-cusped teeth, long upper labial furrows, dorsal fin margins not frayed, relatively small pectoral and pelvic fins, buccopharyngeal denticles confined to anterior end of mouth, and 76 to 86 precaudal centra. It is the only species of Mustelus in temperate Australian waters.
Body fairly slender. Head short, prepectoral length 17 to 21% of total length; snout moderately long and bluntly angular in lateral view, preoral snout 5.7 to 7.4% of total length, preorbital snout 5.8 to 7.8% of total length, internarial space broad, 2.6 to 3.2 % of total length; eyes fairly large, eye length 1.6 to 3.2 times in preorbital snout and 2.4 to 4.2% of total length; interorbital space fairly broad, 3.7 to 5.1% of total length; mouth short, its length subequal to eye length and 3.0 to 3.6% of total length; upper labial furrows considerably longer than lowers and 2.0 to 2.8% of total length; teeth molariform and asymmetric, with cusp reduced to a low point; buccopharyngeal denticles confined to tongue and anteriormost part of palate. Interdorsal space 19 to 23% of total length; trailing edges of dorsal fins denticulate, without bare ceratotrichia; pectoral fins moderately large, length of anterior margins 12 to 16% of total length, width of posterior margin 8 to 13% of total length; pelvic anterior margins 6.2 to 7.9% of total length; anal height 2.5 to 4.4% of total length; anal-caudal space greater than second dorsal height, 6.9 to 8.3% of total length; ventral caudal lobe more or less falcate in adults. Crowns of lateral trunk denticles lanceolate, with longitudinal ridges extending at least half their length. Cranium, hyomandibulae and scapulocoracoids not hypercalcified in adults; palatoquadrates not subdivided; monospondylous precaudal centra 35 to 38, diplospondylous precaudal centra 39 to 50, precaudal centra 76 to 86. Colour grey or grey-brown, above, light below, usually with numerous small white spots but without dark spots or dark bars. Development ovoviviparous. Size larue. adults 68 to 157 cm.
Western South Pacific: Australia (Western and South Australia, Victoria, Tasmania, New South Wales, southern Queensland).
Habitat and Biology:
An abundant inshore and offshore shark of temperate waters, found on or near the bottom and from the intertidal to 183 m. Ovoviviparous, withouta yolk-sac placenta, number of young 5 to 16 per litter. Eats crustaceans, including crabs, marine worms and small fishes.
Maximum 157 cm, males maturing at about 68 cm, females at about 80 cm.
Interest to Fisheries:
This small shark is widely fished in Australia, and utilized fresh for human consumption.
This species is closest to the New Zealand M. Ienticulatus, but differs in having slightly larger pelvic fins and fewer precaudal vertebrae. The author follows Heemstra (1973) in synonymyzing Emissola naugeana with this species. Dr P.C. Heemstra (pers. comm.) regards the larger Western Australian gummy sharks (E. ganearum) as conspecific with M. antarcticus, although he had previously (Heemstra, 1973) kept them as separate species following Whitley.
Syntypes: British Museum (Natural History); BMNH 18188.8.131.52, 870 mm female, New South Wales; BMNH 18184.108.40.206, 1030 mm adult male, Tasmania; an additional syntype, BMNH 18220.127.116.11, is not this species but M. lenticulatus (Heemstra, 1973). Type Locality: "South Pacific" (New South Wales, Tasmania, New Zealand).