Reproduction
An ovoviviparous species with no apparent fixed reproductive season. After gestation, 9 to 20 pups are born in each litter. Each newborn pup is approximately 0.25 m (0.8 ft) in length. (Compagno 2001)
Predators
Larger sharks
Sharpnose sevengill shark embryo. Photo courtesy of Bigelow Schroeder (1948)
Sharpnose sevengill shark embryo. Photo courtesy mexico email list of Bigelow & Schroeder (1948)
Parasites
Nematodes, including Anisakis sp. and Contracaecum sp. are documented to be parasitic on this shark. Other nematode species have been reported from the stomach mucus of the sharpnose sevengill (Henderson and Williams 2001). Crossobothrium dohrnii, is among the many parasitic cestodes found in the gut of this species.
Taxonomy
The sharpnose sevengill shark was described as Heptranchias perlo by Bonnaterre in 1788. The genus name Heptranchias is derived from the Greek "heptra" meaning seven arms and "agchein" meaning accelerator. Synonyms used in earlier scientific literature to refer to this species include Heptranchias cinereus Gmelin 1789, Squalus cinereus Gmelin 1789, Notidanus cinereus Gmelin 1789, Heptrancus angio Costa 1857, Heptranchias angio Costa 1857, Notidanus cinereus age Bellotti 1878, Notidanus cinereus pristiurus Bellotti 1878, Heptranchias deani Jordan & Starks 1901, and Heptranchias dakini Whitley 1931.