The fish were extremely huge with one measuring 1.4 meters long and weighing 25 kilograms, making them the biggest among more than 90 species of slickheads, also known as “sekitori iwashi” (sekitori sardines). "Sekitori" refers to sumo wrestlers in the sport's top two divisions.

The new species was given the Japanese name of “yokozuna iwashi” since it is considered at the top of the bay's deep-sea ecosystem.