Microstomus pacificus

The Pacific Dover sole (Microstomus pacificus), also called the slime sole or slippery sole, is a Pacific flatfish of the flounder family which ranges from Baja California to the Bering Sea. It takes its name from a resemblance to the common sole of Europe, which is often called Dover sole.

Pacific Dover sole can live for 45 years. The species was identified in proximity to a methane seep off the coast of Del Mar in Southern California. They spawn annually in the winter season in deep water between 800 metres (2,600 ft) and 1,000 metres (3,300 ft). Males begin to spawn at four years of age, while females begin to spawn at age five.