Gummy Shark (Mustelus antarcticus):

The alternative names for the Gummy Shark are, Australian smoothed hound, Sweet William, Flake.

A slender, white-spotted hound shark with pavement-like crushing teeth and upper furrows slightly longer than the lower labial furrows, temperate Australia.

Body slender predorsal, interdorsal and postdorsal ridges present. Snout relatively long (preoral length 5.7-7.4% of total length), tip broad and rounded; internarial space 2.6-3.2% of total length; eyes oval, dorsolateral on head; interorbital space relatively broad, 6.5-6.9% of total length; upper labial furrows 2.0-2.8% of total length, slightly longer than lower labial furrows; mouth relatively broad ( length 1.6-1.8 in width). Teeth in both jaws flattened, arrange in a pavement-like pattern, cusp low. First dorsal-fin origin varying from slightly in front to slightly behind free rear tips of pectoral fins. Second dorsal-fin origin in front of anal-fin origin. Second dorsal fin about three-quarters size of first dorsal fin, considerably larger than anal fin. Pectoral fins broad; apices rounded. Caudal fin with deep subterminal notch. Tooth count 62-69/75-84*. Total vertebrae 125-133; precaudal 79-86; monospondylous 34-37.

The gummy shark often occurs in small schools composed predominantly of one sex and size group. Research conducted by way of tagging in Bass Strait and off eastern Tasmania has shown that it is capable of long migrations. Some tagged females were recaptured in South Australia and Western Australia. Similar movements have not shown for males. It is ovoviviparous, producing litters of mostly 14 pups (although the number range from 1-38) in December after a gestation of 11-12 months. Ageing studies suggest that males mature at about 4 and females at about 5 years of age. The diet consists of cephalopods, crustaceans and to a lesser extent, teleost fish.

This species is a major component of the southern Australian shark fishery (current annual production 5000 tonnes, valued at $20 million to the fisherman). It has been exploited heavily since the 1970's and is currently over-fished. The meat, which is used for consumption mostly under the name of "flake", is very popular in Victoria and Tasmania. This gummy shark is difficult to distinguish from relatives off tropical Australia and New Zealand and its distribution range is not well known. More taxonomic work is required on members of this genus in Australasian waters.






Shark Gummy