Hexanchus griseus (Bonnaterre, 1788) .

Bluntnose Sixgill Shark, Mud Shark, or Sixgill Shark. Confirmed to 4.82 m (15.8 ft), and probably to 5.5 m (18 ft) (Ebert et al. 2013). The 6 m (19.7 ft) reference (Roberts et al. 2015) is undocumented and appears to be based on the maximum possible size estimated from a partial specimen (Celona et al. 2005). Circumglobal in temperate and tropical waters; western Pacific Ocean north to southern Japan (Nakaya and Shirai in Masuda et al. 1984); eastern North Pacific Ocean south of Aleutian Islands (Larkins 1964) to Gulf of California (Allen and Robertson 2015) to Chile (Chirichigno and Vélez 1998), including Islas Galápagos (Buglass et al. 2020). Depth: surface to at least 2,490 m (8,167 ft) (min.: Compagno 1984; max.: Weigman 2016). The modifier bluntnose was added to the common name by Compagno (1999); there are two species of sixgill shark, although only one occurs in our area.