", South Africa An opportunistic predator, the broadnose sevengill preys on a great variety of animals, and has been found at depths of , in offshore waters. and
cowsharks),
rays,
chimaeras,
cetaceans,
pinnipeds,
bony fishes and
animal falls (seafloor
carrion). It will also feed on anything that fits in its mouth, such as shark egg cases,
sea snails,
crustaceans and any remains of rats, seabirds, and even deceased drowned humans. Research in 2003 found that its diet consisted of 30% mammals, with a frequency of occurrence of 35%. It is a frequent top predator in shallow waters, and has comb-like teeth, with the upper teeth having slender, smooth edged cusps to swallow small enough prey whole and lower teeth that are broad enough to bite flesh into pieces. These sharks occasionally hunt in packs to take larger prey, using tactics such as stealth to succeed. After feeding, it slowly digests for several days, and can go weeks until eating again. Larger, predatory sharks (such as the
great white shark) can be a threat, and cannibalism among this species has also been recorded. The species has also been observed being preyed upon by
orcas in
False Bay, South Africa. When not actively hunting, it patrols the water, stealthily, while making very little movement except for moving its caudal fin; when prey is detected, they conserve their energy until ready to make an accelerated dash to attack. It can be one of the most abundant predators in coastal waters in summer; for example, in southeastern
Tasmania, there is a high abundance of
elasmobranchs (including the gummy shark) in coastal regions in summer. In New Zealand, it is also one of the most common inshore sharks. While it is mainly a nocturnal forager, it may opportunistically feed on prey casually found during the day; however, research in 2010 noted even amounts of activity during day and night. During this research, the shark was consistently detected at many depths, from bottom to near the surface, although it was mainly near the seafloor during the day. It also found that, as
Norfolk Bay does not have adequate shelter cover, this species may use group formation to avoid predation. with the males maturing at 4 to 5 years and the female 11 to 21 years; the average reproductive age for a female is 20 to 25 years. After a 12-month gestation period, the female moves to a shallow bay or estuary to give birth between April and May to a large litter of between 82 and 95 pups, measuring . In 2004 and 2005, along with research for the
sand tiger shark, there was research for the broadnose sevengill shark for development techniques for semen collection and artificial insemination to potentially increase breeding and lower overreliance on natural mating. Research in 2010 found that this shark has very poorly calcified
vertebrae that cannot be used for age and growth estimations. Research in 2009 in
Ría Deseado (RD) and
Bahía San Julián (SJ), Argentina found that females were larger in RD than SJ and the heaviest female in RD was 70 kg while it was 36.9 kg in SJ. For the males, the heaviest in RD was 40 kg while it was 32.5 in SJ. Both locations also found the most significant to occur December and January. Research in 2014 also found that for the first time, reproductive hormones levels were found in the broadnose sevengill shark. for a few years before venturing out. The probable predators of this species are larger sharks. Research from 2002 showed that although juvenile sevengill sharks utilize nursery areas in a similar way, males mature faster than females even if they are the same size and thus males are more likely to leave the nursery area before females. In 2004, John G Maisey of the
American Museum of Natural History published a detailed analysis of the broadnose sevengill shark including imagery such as
CT scans and
morphology of its braincase. ==Interactions with humans==