Ophiodon elongatus
Blue cod
(Also: Buffalo cod; Cultus cod; Green cod; Leopard cod; Lingcod)

Ophiodon elongatus is native to the west coast of North America, from the Shumagin Islands in the Gulf of Alaska to Baja California, Mexico. Highest densities are found off the coast of British Columbia, Canada. ("FishWatch-Lingcod", 2011; "Lingcod", 2007)

Lingcod are coastal fish that occupy submerged banks with dense communities of algae, and channels with strong currents flowing over and around rocky reefs. They avoid muddy and sandy bottoms, and stagnant areas. Lingcod have been found at depths up to 420 m, though the majority live in waters less than 100 m. Lingcod are tolerant of a broad range of water temperatures. (Shaw and Hassler, 1989)

Body coloration of lingcod is cryptic and variable, but generally consists of dark shades of brownish-green with blotches of copper along the length of the body. The only color consistent among individuals is white, which appears on the ventral side of the gills. The first dorsal fin is larger than the second, and the two dorsal fins together extend nearly the entire length of the body. The mouth is wide and contains about 18 large, inward-curved, sharp teeth. They can grow as large as 36 kg, but average mass is 13 kg. Although mean length for lingcod is unknown, the largest individual on record was 152.4 cm (5 feet) long, and adult females tend to be larger than adult males. ("FishWatch-Lingcod", 2011; Shaw and Hassler, 1989)

The incubation period for lingcod eggs varies with water temperature, but usually lasts between 5 and 12 weeks. Eggs hatch during late winter or early spring. Newly hatched larvae are approximately 7 to 10 mm in length and are transported by ocean currents until they grow large enough to swim about freely. During the planktonic larval period, lingcod grow rapidly, feeding primarily on copepods and other small zooplankton. By mid-summer, when length reaches approximately 80 mm, lingcod larvae become demersal and settle in kelp or eelgrass beds. At this point, larvae begin feeding on juvenile Pacific herring and other small fish. By age two, juvenile lingcod migrate into shallow-water habitats shared by adult lingcod. Growth is rapid during the first 3 years of life. Throughout this period, both sexes display similar growth patterns, and in one year they grow an average of 27 cm. Studies have found that 3-year-old lingcod of either sex average around 50 cm in length. Starting at age 3, females grow faster with increasing age, and males grow more quickly when young. Males begin to mature at age 2 or about 50 cm in length, and females become sexually mature when by age 3 or about 76 cm in length. The number of eggs produced per female increases with size and age, and some egg masses have been reported to weigh as much as 6.8 kg. The largest specimen caught was reportedly 150 cm in length, and weighed 32 kg. Maximum age of lingcod is reported to be 25 years. (Cook and Guthrie, 2005; Shaw and Hassler, 1989; Vincent-Lang, 2007)

Adult lingcod reproduce sexually by means of external fertilization and exhibit both nesting and nest-tending activities. Males attract one or more females to his nesting site. Once at the nesting site, females deposit an egg mass consisting of 40,000 to 500,000 eggs within reef cracks and cavities. Females often lay their eggs in layers, with each layer fertilized before the next layer is laid. A single male fertilizes the egg masses of multiple females. Female lingcod remain monogamous within the breeding season and spawns with only one male, once per breeding season. Unlike males, which return each year to their nesting sites, females exhibit no site fidelity, and mates with a different male at a different location during the following season. (Collins and Nicholson, 2011; King and Withler, 2005)

Adult lingcod spawn seasonally starting in late winter. Spawning takes place between December and April in shallow waters 3 to 10 m in depth over rocky reefs with strong tidal currents. Males become sexually mature by 2 years of age, and females become sexually mature between 3 and 5 years of age. Males migrate as early as September to near shore spawning grounds to establish territorial boundaries and nest sites. The territory of a single male often includes more than one nest site. If a male finds a suitable nesting site he may return to that same site every season until he is no longer capable of spawning. Once a male establishes his nest site, he drives off all other males and begins attracting females to his territory. (Vincent-Lang, 2007)

Female lingcod abruptly leave the nesting site after depositing their eggs. Males are territorial during mating season and aggressively defend their nest against all intruders. There have even been reports of attacks on humans by male lingcod during the mating season. Males remains with fertilized eggs for 8 to 10 weeks throughout development and fan them with their pectoral tail fins to keep them oxygenated and clean. It is not unusual for a small male to protect a nest when the mature male is gone. Small males have also been known to guard loose egg masses that have detached from the reef and settled on the ocean floor. Lingcod eggs are vulnerable to numerous benthic predators; therefore, male nest guarding is important for survival of young. (Collins and Nicholson, 2011; Vincent-Lang, 2007)

Although lingcod can live for up to 25 years, most individuals live close to 20 years in the wild. ("FishWatch-Lingcod", 2011; "Lingcod", 2007)

Lingcod are solitary, benthic fish and spend most of their time resting within holes or crevices amongst rocks. Lingcod's cryptic coloration helps it to blend into its rocky surroundings, where it lies in wait to ambush any prey that swims by. Lingcod have also been seen moving into shallower waters at night to feed. ("Lingcod", 2007; Shaw and Hassler, 1989)

The majority of lingcod are fairly sedentary and do not migrate far from their home reef. Lingcod spend approximately 95% of their adult lives within an 8 km^2 area. ("Lingcod", 2007)

Although there is little information on communication and perception specific to lingcod, like many other species of Teleostei, they use vision, chemical perception via the nares, the lateral line system, and hearing to perceive their environment. ("Pelagic and Non-Pelagic Rockfish", 2011)

Lingcod are ambush predators that eat anything that can fit in their mouths, especially fish and large invertebrates. Lingcod exhibit cannibalism and prey on various species of salmon and rockfish as well as Pacific herring and octopus. ("FishWatch-Lingcod", 2011; Shaw and Hassler, 1989)

Lingcod are cryptically colored and spend most of their time hiding underneath overhangs, amongst rocks, and within holes. As adults, lingcod have long, sharp teeth to deter potential predators. Humans are the most significant predator of lingcod, which were considered overfished in the late 90's. Since then, multiple regulations have been put into place to reduce the annual harvest rates of lingcod. Other important predators include Stellar sea lions, California sea lions, harbor seals, and sharks. ("FishWatch-Lingcod", 2011; Shaw and Hassler, 1989)

Lingcod are important secondary and tertiary consumers within the benthic community. They are ambush predators and prey upon squid, octopuses, crabs, fish, and smaller lingcod. They are also an important prey species for numerous species of marine mammal. Lingcod eggs are eaten by gastropod mollusks, crabs, echinoderms, kelp greenlings, and cabezon, while larvae and juveniles may be consumed by anything larger than themselves. ("FishWatch-Lingcod", 2011; "Lingcod", 2007)

Little information is known of parasites specific to lingcod, however, they are known to host the nematode Cucullanus elongatus and the copepod Chondracanthus narium. ("FishWatch-Lingcod", 2011; "Lingcod", 2007)

From 1943 to 1950, commercial landings of lingcod ranged from 326,000 to 950,000 kg per year, primarily due to strong markets for fish liver oil. From 1972 to 1982, landings significantly increased to 1,360,000 kg per year, due to rapid expansion of trawl fishing along the Pacific west coast. Since the late 1980's, lingcod landings have steadily declined, both in total weight and number of fish caught. In 1999, the commercial harvest peaked at 142,000 kg and was valued at $283,000. By 2009, commercial landings had decreased to around 57,000 kg, valued at $184,000. In 1980, the recreational catch totaled 626,945 fish, compared to 30,477 fish landed in 2008. This reduction reflects the catch limits imposed by management plans that were implemented by California Department of Fish and Game to conserve rockfish populations along the Pacific coast of the United States. (Adams and Starr, 2001; Lynn, 2008)

There are no known adverse effects of lingcod on humans.

Lingcod have not been evaluated by the IUCN, and therefore, populations trends and potential conservation needs are currently unknown.