Gadus macrocephalus, known as the Pacific Cod, is a saltwater fish that belongs to the order Gadiformes, Gadidae and  has a robust, elongated body with a large head and a prominent mouth.

Habitat and Distribution

This cod is found in the northern Pacific Ocean, from the waters of Japan to the west coast of North America and it prefers cold, deep waters, often near the sea floor.

Diet

It feeds on a variety of marine organisms, including smaller fish, crustaceans, and invertebrates and its diet varies depending on the season and habitat (1).

Reproduction

Reproduction occurs in winter. Females lay eggs in deep waters, when young Pacific Cod spend their early years in shallow waters before migrating to more open waters (2).

Economic Importance

Pacific Cod is a heavily fished species, especially for the production of fillets and the frozen fish industry and it is an important food source and plays a significant role in the fishing economy.

Conservation

The species is subject to overfishing in some areas, necessitating sustainable fishery management.

Efforts are underway to monitor populations and regulate fishing.

Genome

For Gadus macrocephalus, the complete mitochondrial genome sequences are currently known, but the genome sequences are relatively less known and are illustrated in this study (3).

Culinary Uses

Baking: Cod is often baked with various seasonings, herbs, and sauces. Baking retains the moisture in the fish and allows it to absorb the flavors.

Frying: Cod is a popular choice for fish and chips. It can be battered and deep-fried to create a crispy coating while maintaining the tender flesh inside.

Grilling: Grilling cod over an open flame or on a grill pan can impart a smoky flavor and create grill marks for added visual appeal.

Poaching: Cod can be poached in simmering liquid, such as a court bouillon, to keep it moist and flavorful.

Pan-Searing: Searing cod in a hot skillet with oil or butter can result in a golden-brown crust while keeping the inside flaky and tender.

Broiling: Cod fillets or steaks can be broiled in the oven with seasonings and a drizzle of olive oil for a quick and flavorful preparation.

Fish Tacos: Cod is a common choice for making fish tacos. It's often seasoned with spices and served in tortillas with various toppings and sauces.

Culinary Pairings

Lemon and Herbs: Cod pairs well with lemon juice and herbs like parsley, dill, and tarragon for a fresh and aromatic flavor.

Tomatoes and Olives: Cod can be combined with tomatoes, olives, and capers for Mediterranean-inspired dishes.

Potatoes: Cod is traditionally served with potatoes in dishes like "Bacalao a la Vizcaína" or "Fisherman's Pie."

Garlic and Butter: Garlic butter is a classic accompaniment to cod, enhancing its flavor with rich, savory notes.

Other Uses

Fishery: Cod is a commercially important fish species, and it supports extensive fisheries in various parts of the world.

Fish Farming: In addition to wild-caught cod, there is also a growing aquaculture industry for cod, which helps meet the demand for this popular fish.

Conservation: In some regions, cod populations have faced overfishing and conservation efforts have been put in place to protect and restore their numbers.

References_____________________________________________________________________

(1) Choi, D. H., Sohn, M. H., Kim, M. J., & Lee, S. J. (2019). Feeding habits of Pacific cod (Gadus macrocephalus) in the west coast of Yellow Sea of Korea. Korean Journal of Ichthyology, 31(2), 77-82.

Abstract. The feeding habits of pacific cod (Gadus macrocephalus) were studied by analyses of stomach contents. Specimens of G. macrocephalus (n=407) were collected from the western coastal waters of Korea, monthly from July 2017 to June 2018. The size of G. macrocephalus ranged from 30.4 to 86.0 cm in total length (TL). G. macrocephalus was consumed mainly Pisces (71.5%) and Caridea (24.2%) based on % IRI, whereas other prey items including, Paguroidea, Euphausiacea and Cephalopods showed a low contribution to the diet. The feeding ratio of Caridea decreased with increasing fish size. While this decrease paralleled the increased consumption of fish preys. The feeding ratios of Pisces were the highest during spring, autumn and winter, whereas the proportion of Caridea was higher in summer.

(2) Smirnova, M. A., Orlova, S. Y., & Orlov, A. M. (2019). The population genetic organization of Pacific cod Gadus macrocephalus in the North Pacific based on microsatellite analysis. Journal of Ichthyology, 59, 555-565.

Abstract. Six groups have been identified in the species' population structure based on the analysis of microsatellite markers' polymorphism in Pacific cod Gadus macrocephalus samples within the entire western part of the North Pacific, including waters of the Pacific coast of Canada. The first group includes cod from waters of the Yellow Sea; the second group consists of cod from the Sea of Japan (eastern coast of Korea and Peter the Great Bay); the third group combines cod from Tatar Strait and the South Kuril Islands (both Sea of Okhotsk and Pacific Ocean sides); the fourth group is formed by cod from the northwestern Sea of Okhotsk and Taui Bay; the fifth-largest group includes cod from waters off western Kamchatka, the North Kuril Islands (Sea of Okhotsk and Pacific Ocean sides), Karaginsky Bay, Navarinsky area in the Bering Sea, and Anadyr Bay; the sixth group is formed by cod from coastal waters of Canada.

(3) Ma Y, Lou F, Yin X, Cong B, Liu S, Zhao L, Zheng L. Whole-genome survey and phylogenetic analysis of Gadus macrocephalus. Biosci Rep. 2022 Jul 29;42(7):BSR20221037. doi: 10.1042/BSR20221037. PMID: 35788826; PMCID: PMC9289796.

Abstract. Gadus macrocephalus (Pacific cod) is an economically important species on the northern coast of the Pacific. Although numerous studies on G. macrocephalus exist, there are few reports on its genomic data. Here, we used whole-genome sequencing data to elucidate the genomic characteristics and phylogenetic relationship of G. macrocephalus. From the 19-mer frequency distribution, the genome size was estimated to be 658.22 Mb. The heterozygosity, repetitive sequence content and GC content were approximately 0.62%, 27.50% and 44.73%, respectively. The draft genome sequences were initially assembled, yielding a total of 500,760 scaffolds (N50 = 3565 bp). A total of 789,860 microsatellite motifs were identified from the genomic data, and dinucleotide repeat was the most dominant simple sequence repeat motif. As a byproduct of whole-genome sequencing, the mitochondrial genome was assembled to investigate the evolutionary relationships between G. macrocephalus and its relatives. On the basis of 13 protein-coding gene sequences of the mitochondrial genome of Gadidae species, the maximum likelihood phylogenetic tree showed that complicated relationships and divergence times among Gadidae species. Demographic history analysis revealed changes in the G. macrocephalus population during the Pleistocene by using the pairwise sequentially Markovian coalescent model. These findings supplement the genomic data of G. macrocephalus, and make a valuable contribution to the whole-genome studies on G. macrocephalus. © 2022 The Author(s).