The chub mackerel, Pacific mackerel, or Pacific chub mackerel (''Scomber japonicus'') is a species of fish in the tuna and mackerel family,

Scombridae The mackerel, tuna, and bonito family, Scombridae, includes many of the most important and familiar food fishes. The family consists of 51 species in 15 genera and two subfamilies. All species are in the subfamily Scombrinae, except the butte ...

. This species of

mackerel Mackerel is a common name applied to a number of different species of pelagic fish, mostly from the family Scombridae. They are found in both temperate and tropical seas, mostly living along the coast or offshore in the oceanic environment. ...

closely resembles the

Atlantic chub mackerel Atlantic chub mackerel (''Scomber colias''), also known as Tinker mackerel, is a pelagic schooling species of mackerel found in the Atlantic Ocean, the Mediterranean Sea, and the Black Sea. It was originally thought to be a subspecies of the ch ...

Characteristics

The chub mackerel has a well-developed swim bladder attached with the

esophagus The esophagus (American English) or oesophagus (British English; both ), non-technically known also as the food pipe or gullet, is an organ in vertebrates through which food passes, aided by peristaltic contractions, from the pharynx to t ...

, which the "true mackerels" in the genus ''Scomber'' lack, and a characteristic color difference is seen between the chub and the Atlantic chub, the latter being silvery-sided below the midline, whereas the lower part of the sides of the chub (otherwise colored somewhat like the Atlantic) are mottled with small dusky blotches, and the chub has a larger eye than the Atlantic. Less obvious differences are that the

dorsal fin A dorsal fin is a fin located on the back of most marine and freshwater vertebrates within various taxa of the animal kingdom. Many species of animals possessing dorsal fins are not particularly closely related to each other, though through c ...

s are closer together in the chub and only 9 or 10 spines are in its first dorsal fin instead of 11 or more, which is the usual count in the Atlantic mackerel. In most species, the mackerel is known to travel in large schools. It is a smaller fish than its better-known relatives, growing to a length around . Scombridae - Scomber japonicus

Habits

Chub mackerel school like Atlantic mackerel, and their feeding habits are much the same, eating the same species of

pelagic The pelagic zone consists of the water column of the open ocean, and can be further divided into regions by depth (as illustrated on the right). The word ''pelagic'' is derived . The pelagic zone can be thought of as an imaginary cylinder or w ...

crustacean Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapoda, decapods, ostracoda, seed shrimp, branchiopoda, branchiopods, argulidae, fish lice, krill, remipedes, isopoda, isopods, barnacles, copepods, ...

s and Sagittae that the mackerel had taken at the same time and place, while specimens taken at

Woods Hole Woods Hole is a census-designated place in the town of Falmouth in Barnstable County, Massachusetts, United States. It lies at the extreme southwest corner of Cape Cod, near Martha's Vineyard and the Elizabeth Islands. The population was 781 at ...

ate chiefly

copepod Copepods (; meaning "oar-feet") are a group of small crustaceans found in nearly every freshwater and saltwater habitat. Some species are planktonic (inhabiting sea waters), some are benthic (living on the ocean floor), a number of species have ...

s, to a lesser extent on

amphipod Amphipoda is an order of malacostracan crustaceans with no carapace and generally with laterally compressed bodies. Amphipods range in size from and are mostly detritivores or scavengers. There are more than 9,900 amphipod species so far descri ...

s, salps,

appendicularians Larvaceans, class Appendicularia, are solitary, free-swimming tunicates found throughout the world's oceans. Like most tunicates, larvaceans are filter feeders. Unlike most other tunicates, they live in the pelagic zone, specifically in the photi ...

, and young

herring Herring are forage fish, mostly belonging to the family of Clupeidae. Herring often move in large schools around fishing banks and near the coast, found particularly in shallow, temperate waters of the North Pacific and North Atlantic Ocean ...

. They follow thrown bait as readily and bite quite as greedily as Atlantic mackerel do. Their breeding habits have not been studied.

Fossil record

Fossils of ''Scomber japonicus'' have been found in the

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58Indo-Pacific The Indo-Pacific is a vast biogeographic region of Earth. In a narrow sense, sometimes known as the Indo-West Pacific or Indo-Pacific Asia, it comprises the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the ...

. They are absent from the

Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or ~19.8% of the water on Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia to the east. To the south it is bounded by ...

except for

South Africa South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring coun ...

from

KwaZulu-Natal KwaZulu-Natal (, also referred to as KZN and known as "the garden province") is a province of South Africa that was created in 1994 when the Zulu bantustan of KwaZulu ("Place of the Zulu" in Zulu) and Natal Province were merged. It is loca ...

Western Cape The Western Cape is a province of South Africa, situated on the south-western coast of the country. It is the fourth largest of the nine provinces with an area of , and the third most populous, with an estimated 7 million inhabitants in 202 ...

, and are replaced by the closely related

in the

Atlantic The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe ...

. The chub mackerel is widely distributed, usually found in the northwestern, southeastern, and northeastern Pacific. In the eastern Pacific, it can be found from central Mexico to southeastern Alaska. Chub mackerel are generally found within 20 miles (37 km) off the coast in waters between 50 and 72 °F (10 to 22 °C). Young mackerel live around sandy beaches or kelp beds, while adults are found in deeper waters in shallow banks to 1000 feet (300 m) deep. Chub mackerel school with other pelagic species, as well such as other types of mackerels and sardines. In 2015 chub mackerels were found in Indian Ocean and the new species were classified as Scomber indicus.

Diet

larvae A larva (; plural larvae ) 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. T ...

, chub mackerel feed mainly on

s and

rotifer The rotifers (, from the Latin , "wheel", and , "bearing"), commonly called wheel animals or wheel animalcules, make up a phylum (Rotifera ) of microscopic and near-microscopic pseudocoelomate animals. They were first described by Rev. John H ...

s and sometimes even smaller larvae of their own kind. Chub mackerel larvae can consume up to 87% of their dry body weight a day. As juveniles, chub mackerel feed mainly on

zooplankton Zooplankton are the animal component of the planktonic community ("zoo" comes from the Greek word for ''animal''). Plankton are aquatic organisms that are unable to swim effectively against currents, and consequently drift or are carried along by ...

. As adults, they feed on

mysid Mysida is an order of small, shrimp-like crustaceans in the malacostracan superorder Peracarida. Their common name opossum shrimps stems from the presence of a brood pouch or "marsupium" in females. The fact that the larvae are reared in this ...

s and euphausids.

Spawning and maturation

Spawning between chub mackerel typically occurs at temperatures of 59 to 68 °F. This in turn, leads to different mating seasons depending on what part of the hemisphere they are located. Females lay about 100,000 to 400,000 eggs during breeding season. The mackerel is constantly competing with other fish for food. Although maturation of chub mackerel has never been thoroughly documented, data show that spawning can happen from March through October, but mostly happens from April through August. Sometimes in females, ripe translucent eggs appear simultaneously with unripe ova in early stages of development; this is also seen with the Atlantic mackerel.

Defense mechanisms

The chub mackerel relies on camouflaging itself to stay hidden from its predators. It has a dorsal pattern very similar to the light pattern of the waves and sun. When in danger, the fish move close to the surface of the water to merge with the flickering light of the sun making them difficult to see from above, which protects them from predatory birds. The countershading on their ventral surfaces likewise makes it difficult for larger predatory fish like tuna and barracuda to pick them out from the background.

Fisheries

Known to fisherman as the hardhead, the chub mackerel is regularly fished and canned for human consumption, pet food, bait, or served fresh. From 1980 to 1989, the recreational catch average in California was 1,462 tons. Since they have begun being fished, the chub mackerel reached its catching peak in 1978 with 3,412,602 tons. Since 1978, the catch ratings have continued to decrease, but picked back up a little in 1995. The ideal method for catching chub mackerel is round-haul gear such as

purse seine Seine fishing (or seine-haul fishing; ) is a method of fishing that employs a surrounding net, called a seine, that hangs vertically in the water with its bottom edge held down by weights and its top edge buoyed by floats. Seine nets can be de ...

s. Bycatch is low because nets are placed directly on schools of fish. Chub mackerel are caught all year round, but especially between June and November. They can be caught on both sides of North America, but the most important fisheries commercially are in California and Mexico.

As food

According to nutrition specialists, the chub mackerel is a healthy meal, high in protein and rich in omega-3 and unsaturated fatty acids. Due to its high energy and protein intake, and low carbohydrate value, it is recommended in the diets of growing children and pregnant women, although it may contain high levels of heavy metals. The chub mackerel is a popular dish in Sicilian cuisine, in which it is served in a variety of ways. In the Sicilian culture, the chub mackerel is called a variety of names, ''strummu ucchiutu'', ''varatulu scrummu'', or ''occhiutu''. In the kitchen and market, the fish is in the best condition if the meat is firm and the eyes are clear with the colors bright. For the most part, it is eaten fresh, but can be seen pickled or frozen. In Sicilian cuisine, it is also served filleted and raw, marinated in oil, lemon, salt, and pepper.Chub mackerel , FEP." Sicilian Castro Hernández, J.J.; Santana Ortega, A.T. Fish on the Road - Regione Siciliana. N.p., n.d. Web. 21 Apr. 2013..

Jorim ''Jorim'' () is a simmered Korean dish, made by boiling vegetables, meat, fish, seafood, or tofu in seasoned broth until the liquid is absorbed into the ingredients and reduced down. ''Jorim'' dishes are usually soy sauce-based, but gochu ...

is a Korean dish made with tofu, vegetables, meat and seafood. Mackerel is also one of the most popular foods for Koreans as jorim. File:Godeungeo-hoe.jpg, ''Godeungeo-

hoe Hoe or HOE may refer to: * Hoe (food), a Korean dish of raw fish * Hoe (letter), a Georgian letter * Hoe (tool), a hand tool used in gardening and farming ** Hoe-farming, a term for primitive forms of agriculture * Backhoe, a piece of excavating ...

'' (raw chub mackerel) File:Godeungeo jaban (salted chub mackerel).jpg, Salted chub mackerel File:Gan-godeungeo.jpg, ''Gan-godeungeo'', salted mackerel dish of

Andong Andong () is a city in South Korea, and the capital of North Gyeongsang Province. It is the largest city in the northern part of the province with a population of 167,821 as of October 2010. The Nakdong River flows through the city. Andong is a ...

References

Further references

* *
Pacific mackerel
''NOAA FishWatch''. Retrieved 11 November 2012. *Collette, B., et al. 2011
''Scomber japonicus''.
In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2. Downloaded on 7 June 2013.

External links

* Photos o
Scomber japonicus
in iNaturalist {{Taxonbar, from=Q815837 Scomber Fish of East Asia Fish described in 1782 Fish of Japan Fish of Korea Taxa named by Martinus Houttuyn