Lingcod
Encyclopedia
The lingcod, Ophiodon elongatus, is a fish of the greenling family Hexagrammidae
. It is the only extant member of the genus Ophiodon. A slightly larger, extinct species, Ophiodon ozymandias, is known from fossils from the Late Miocene
of Southern California.
Ophiodon elongatus is native to the North America
n west coast from Shumagin Islands
in the Gulf of Alaska
to Baja California
, Mexico
. It has been observed up to a size of 152 cm (60 in) and a weight of 59 kg (130 lbs).
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. The lingcod's flesh is sometimes blue-green prior to cooking.
, 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 feet). Tagging studies have shown that lingcod are a largely non-migratory species, with colonization and recruitment occurring in localized areas only.
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 photo to the right shows a nest-guarding male protecting his egg mass.
The larva
e are pelagic until late May or early June when they settle to the bottom as juvenile
s. Initially they inhabit eel grass beds, then moving to flat sandy areas that are not 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 3–5 years (61–75 cm) and age 2 years (45 cm), respectively. Adult males can be distinguished externally from females by the presence of a small, conical papilla behind the anal vent. Up to age 2 males and females grow at similar rates, with both reaching an average length of 45 cm. After age 2, females grow faster than males, with the growth of males tapering off at about age 8, and females continuing to grow until about age 12 to 14. Lingcod live up to a maximum of about 14 years for males and 20 years for females, reaching a maximum size of approximately 90 cm and 120 cm, respectively. Off Alaska, many reach 70 pounds (32 kilograms).
Lingcod are voracious predators, feeding on nearly anything they can fit in their mouths including invertebrate
s and many species of fish, such as herring
, Clupea harengus, salmon and Pacific hake, Merluccius productus. One of their favorite foods are smaller octopus, and they will 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 lion
s and harbor seal
s.
published an article showing that cross sections of the 4th to 8th fin rays from the second dorsal fin
provided a method for estimating the age of lingcod. This method has since been validated by a mark-recapture study in which lingcod received an injection of oxytetracycline
(OTC). Other methods of aging, such as those using scales and otolith
s, were found to underestimate ages for older fish.
Ages are determined from fins in much the same manner as for other aging structures: sections of varying thickness are examined under a microscope, and the annuli, or rings, that are formed for each year of growth are counted and used to estimate the age. The cross sections must be made at right angles to the length of the fin ray, and it is therefore important that fins be dried flat, with the cut surface at right angles to the fin rays. In addition, the distance that the section is cut from the fin-ray base is important, and for this reason, all fins should be collected with the base intact.
One problem associated with using fin rays to age older fish, is that the fin-ray center may be resorbed, resulting in the loss of the first two annuli. It is therefore necessary to determine an average width for the first two annuli by examining the fins from juvenile fish. This measurement can then be used to estimate the position of the third annulus on older fish.
Hexagrammidae
The family of marine fishes Hexagrammidae incorporates the greenlings. These fish are found on the continental shelf in the temperate or subarctic waters of the North Pacific. They are a well-known family in the littoral zone from southern California north to the Aleutian Islands...
. It is the only extant member of the genus Ophiodon. A slightly larger, extinct species, Ophiodon ozymandias, is known from fossils from the Late Miocene
Late Miocene
The Late Miocene is a sub-epoch of the Miocene Epoch made up of two stages. The Tortonian and Messinian stages comprise the Late Miocene sub-epoch....
of Southern California.
Ophiodon elongatus is native to the North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
n west coast from Shumagin Islands
Shumagin Islands
The Shumagin Islands are a group of 20 islands in the Aleutians East Borough south of the mainland of Alaska, USA, at54°54'–55°20' North 159°15'–160°45' West. The largest islands are Unga Island, Popof Island, Korovin Island, and Nagai Island. Other islands include Andronica, Big Koniuji, Little...
in the Gulf of Alaska
Gulf of Alaska
The Gulf of Alaska is an arm of the Pacific Ocean defined by the curve of the southern coast of Alaska, stretching from the Alaska Peninsula and Kodiak Island in the west to the Alexander Archipelago in the east, where Glacier Bay and the Inside Passage are found.The entire shoreline of the Gulf is...
to Baja California
Baja California
Baja California officially Estado Libre y Soberano de Baja California is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is both the northernmost and westernmost state of Mexico. Before becoming a state in 1953, the area was known as the North...
, Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
. It has been observed up to a size of 152 cm (60 in) and a weight of 59 kg (130 lbs).
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
Common Ling
The common ling or simply the ling, Molva molva, is a large member of the cod family. An ocean fish whose habitat is in the Atlantic region and can be found around Iceland, Faroe Islands, British Isles, the Norse coast and occasionally around Newfoundland, the ling has a long slender body that can...
or Cod
Cod
Cod is the common name for genus Gadus, belonging to the family Gadidae, and is also used in the common name for various other fishes. Cod is a popular food with a mild flavor, low fat content and a dense, flaky white flesh. Cod livers are processed to make cod liver oil, an important source of...
, the name lingcod originated because it somewhat resembles those fish. The lingcod's flesh is sometimes blue-green prior to cooking.
Life history
Lingcod are unique to the west coast of North AmericaNorth America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
, with the center of abundance off the coast of British Columbia
British Columbia
British Columbia is the westernmost of Canada's provinces and is known for its natural beauty, as reflected in its Latin motto, Splendor sine occasu . Its name was chosen by Queen Victoria in 1858...
. They are found on the bottom with most individuals occupying rocky areas at depths of 10 to 100 m (32 to 328 feet). Tagging studies have shown that lingcod are a largely non-migratory species, with colonization and recruitment occurring in localized areas only.
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 photo to the right shows a nest-guarding male protecting his egg mass.
The larva
Larva
A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...
e are pelagic until late May or early June when they settle to the bottom as juvenile
Juvenile (organism)
A juvenile is an individual organism that has not yet reached its adult form, sexual maturity or size. Juveniles sometimes look very different from the adult form, particularly in terms of their colour...
s. Initially they inhabit eel grass beds, then moving to flat sandy areas that are not 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 3–5 years (61–75 cm) and age 2 years (45 cm), respectively. Adult males can be distinguished externally from females by the presence of a small, conical papilla behind the anal vent. Up to age 2 males and females grow at similar rates, with both reaching an average length of 45 cm. After age 2, females grow faster than males, with the growth of males tapering off at about age 8, and females continuing to grow until about age 12 to 14. Lingcod live up to a maximum of about 14 years for males and 20 years for females, reaching a maximum size of approximately 90 cm and 120 cm, respectively. Off Alaska, many reach 70 pounds (32 kilograms).
Lingcod are voracious predators, feeding on nearly anything they can fit in their mouths including invertebrate
Invertebrate
An invertebrate is an animal without a backbone. The group includes 97% of all animal species – all animals except those in the chordate subphylum Vertebrata .Invertebrates form a paraphyletic group...
s and many species of fish, such as herring
Herring
Herring is an oily fish of the genus Clupea, found in the shallow, temperate waters of the North Pacific and the North Atlantic oceans, including the Baltic Sea. Three species of Clupea are recognized. The main taxa, the Atlantic herring and the Pacific herring may each be divided into subspecies...
, Clupea harengus, salmon and Pacific hake, Merluccius productus. One of their favorite foods are smaller octopus, and they will 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 lion
Sea Lion
Sea lions are pinnipeds characterized by external ear-flaps, long fore-flippers, the ability to walk on all fours, and short thick hair. Together with the fur seal, they comprise the family Otariidae, or eared seals. There are six extant and one extinct species in five genera...
s and harbor seal
Harbor Seal
The harbor seal , also known as the common seal, is a true seal found along temperate and Arctic marine coastlines of the Northern Hemisphere...
s.
Age determination of lingcod
In 1977, Dr. Dick Beamish and Doris Chilton of the Pacific Biological StationPacific Biological Station
The Pacific Biological Station is located on Hammond Bay Road in Nanaimo, British Columbia, Canada. Established in 1908, it is the oldest fisheries research center on the Pacific coast. Operated by Fisheries and Oceans Canada, the station forms a network with eight other scientific...
published an article showing that cross sections of the 4th to 8th fin rays from the second dorsal fin
Dorsal fin
A dorsal fin is a fin located on the backs of various unrelated marine and freshwater vertebrates, including most fishes, marine mammals , and the ichthyosaurs...
provided a method for estimating the age of lingcod. This method has since been validated by a mark-recapture study in which lingcod received an injection of oxytetracycline
Oxytetracycline
Oxytetracycline was the second of the broad-spectrum tetracycline group of antibiotics to be discovered.Oxytetracycline works by interfering with the ability of bacteria to produce proteins that are essential to them. Without these proteins the bacteria cannot grow, multiply and increase in numbers...
(OTC). Other methods of aging, such as those using scales and otolith
Otolith
An otolith, , also called statoconium or otoconium is a structure in the saccule or utricle of the inner ear, specifically in the vestibular labyrinth of vertebrates. The saccule and utricle, in turn, together make the otolith organs. They are sensitive to gravity and linear acceleration...
s, were found to underestimate ages for older fish.
Ages are determined from fins in much the same manner as for other aging structures: sections of varying thickness are examined under a microscope, and the annuli, or rings, that are formed for each year of growth are counted and used to estimate the age. The cross sections must be made at right angles to the length of the fin ray, and it is therefore important that fins be dried flat, with the cut surface at right angles to the fin rays. In addition, the distance that the section is cut from the fin-ray base is important, and for this reason, all fins should be collected with the base intact.
One problem associated with using fin rays to age older fish, is that the fin-ray center may be resorbed, resulting in the loss of the first two annuli. It is therefore necessary to determine an average width for the first two annuli by examining the fins from juvenile fish. This measurement can then be used to estimate the position of the third annulus on older fish.