lists a maximum of 49 years. with the male 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. Conservation and relationship to humans The broadnose sevengill is listed by the IUCN Red List as Vulnerable throughout its range. This species likely suffers great ongoing pressure from various types of fisheries, and from frequently being caught as bycatch. In Argentina, it's fished by rod and reel and broadnose sevengill shark fishing competitions have been occurring since the 1960s. It is also threatened by water pollution and is hunted for its liveroil and hide which is considered good quality in places such as China. In the early 1980s, intense fishing in the San Francisco Bay caused a local