Somniosus pacificus Bigelow & Schroeder, 1944 .

Mud Shark or Pacific Sleeper Shark. To at least 4.3 m (14.1 ft) (Ebert 1987), with unconfirmed, deep-water observations to 7.0 m (23 ft) (Yano et al. 2007). Taiwan to Bering Sea to south-eastern Chukchi Sea (66°20’ N, 165°47’W), and on Russian side of southern Chukchi Sea (Mecklenburg and Steinke 2015) to Pacific Ocean off southern Baja California (Compagno 1984). Possible hybrids of this species and Somniosus microcephalus (Bloch & Schneider, 1801) have been taken somewhat west of Baffin Bay, eastern Canada (Hussey et al. 2015). There is one anecdotal report of a large shark (possibly this species) that was taken near Tuktoyaktuk, northwest Territory, Canada (Reist in Coad and Reist 2018). Reports of S. pacificus as far south as Pisco, Peru (Chirichigno and Vélez 1998) and Bahía de San Antonio, Chile (33°35’S) (Brito 2004a) are not considered valid and probably represent S omniosus antarcticus Whitley, 1939 (Ebert et al. 2009). Depth: surface, intertidal to about 2,205 m (7,232 ft) (min.: Bright 1959; max.: Yeh and Drazen 2009); at the greatest depths in the southern part of the range.