Weasel sharks belong to the largest group of sharks in the world (ground sharks or Carcharhiniformes), who are all distinguished by the presence of a nictitating membrane (a third eyelid that can be drawn across the eye for protection but still allows the animal to see), two dorsal fins, and a single anal fin.
The Australian weasel shark is a common ground shark found mostly in the waters to the north of Australia. They have slender bodies and a drab grey coloring with sickle-shaped fins. The tips of the fins are much darker than the rest. There is a prominent lateral line which runs from the shark’s gills to the base of its tail. They feed primarily on octopuses and other cephalopods and are harmless to human
The weasel shark is a prolific species, with females giving birth to as many as eighteen live young at a time. The six month gestation period is also much shorter than other sharks. Both of these factors have made it a more resilient species in a part of the ocean where sharks are often imperiled.
Weasel sharks start out their lives living on the sandy ocean floor or in sea grass beds along the continental shelf and inshore bays. As they age, they will transition to coral reefs. They generally will not be found any deeper than 170 m (558 feet).
The weasel shark is an occasional victim of by-catch for commercial fisheries in the southern Pacific. Thanks to protective regulations and monitoring, along with the shark’s fast reproductive rate, the International Union of Conservation of Nature and Natural Resources considers it a species of “least concern.”