The lingcod or ling cod (Ophiodon elongatus), also known as the buffalo cod or cultus cod, is a fish of the greenling family Hexagrammidae. It is the only extant member of the genus Ophiodon.[2] A slightly larger, extinct species, Ophiodon ozymandias, is known from fossils from the Late Miocene of Southern California.[3]

Ophiodon elongatus is native to the North American west coast from Shumagin Islands in the Gulf of Alaska to Baja California, Mexico. It has been observed up to a size of 152 centimetres (60 in) and a weight of 59 kilograms (130 lb).[4] It is spotted in various shades of grey. The lingcod is a popular eating fish, and is thus prized by anglers. Though not closely related to either ling or cod, the name "lingcod" originated because it somewhat resembles those fish. Around 20% of lingcods have blue-green to turquoise flesh.[5]p.298 The colour is destroyed by cooking.[6] The colour may be due to biliverdin, but this has not been established beyond doubt.

Lingcod are endemic to the west coast of North America, with the center of abundance off the coast of British Columbia. They are found on the bottom, with most individuals occupying rocky areas at depths of 10 to 100 m (32 to 328 ft). Tagging studies have shown lingcod are a largely nonmigratory species, with colonization and recruitment occurring in localized areas only.[8]

Starting in October, lingcod migrate to nearshore spawning grounds. The males migrate first, and establish nest sites in strong current areas in rock crevices or on ledges. Spawning takes place between December and March, and females leave the nest site immediately after depositing eggs. Males actively defend the nest from predators until the eggs hatch in early March through late April.

The larvae are pelagic until late May or early June, when they settle to the bottom as juveniles. Initially they inhabit eelgrass beds, then move to flat, sandy areas that are not the typical habitat of older lingcod. They eventually settle in habitats of similar relief and substrate as older lingcod, but remain at shallower depths for several years.

Females and males mature at age three to five years (61–75 centimetres (24–30 in)) and two years of age (45 centimetres (18 in)), respectively. An adult male can be distinguished externally from a female by the presence of a small, conical papilla behind the anal vent. Up to age two, males and females grow at similar rates, with both reaching an average length of 45 centimetres (18 in). After age two, females grow faster than males, with the growth of males tapering off at about age eight, and females continuing to grow until about age 12 to 14. Lingcod live a maximum of about 14 years for males and 20 years for females, reaching a maximum size around 90 centimetres (35 in) and 120 centimetres (47 in), respectively. Off the coast of Alaska, many reach 70 pounds (32 kg).

Lingcod are voracious predators, feeding on nearly anything they can fit in their mouths, including invertebrates and many species of fish, such as herring (Clupea pallasii), salmon, and Pacific hake (Merluccius productus). One of their favorite foods is smaller octopuses, and they also readily devour large rockfish. Lingcod that survive the larval stages have few predators themselves, and are vulnerable mainly to marine mammals, such as sea lions and harbor seals.