Sebastes schlegelii also known as the Korean rockfish, is a predatory species of seaperch found in northern Asia. The species is a popular quarry for anglers. S. schlegelii are blackish with black pelvic, anal and caudal fins. The seaperch has a total of 8 weak head spines. It is black when young and turns a mottled gray on the sides with age, often nearing white. This species can vary greatly in size between bodies of water. They can live for up to 18 years, and older individuals are often much larger than average; the maximum recorded length is 60 cm (24 in). The record is 6.6 lb (3 kg). It is a pelagic fish, occurring on the continental shelf. Like other pelagic fish, they spend most of their time amid the water columns and are generally associated with rougher terra. This can make it somewhat inconvenient for commercial fisheries, which are often situated in nearshore, shallow water, and rocky areas (reefs). They make up an important component of nearshore fisheries in northern Asia. S. schlegelii breed via internal fertilization, females storing sperm until the development of the eggs. The phases between the start of the process and the end are separated by several months. The majority of the young are reared in late winter to early spring. Females produce between 125,000 and 1,200,000 eggs every breeding season. However it has been noted that not all of the eggs are released every year. It has been occasionally observed that the female may absorb the eggs back into her system. Lepeophtheirus elegans is a species of sea lice reported on S. schlegelii.