The blue mackerel (''Scomber australasicus''), also called Japanese mackerel, Pacific mackerel, slimy mackerel or spotted chub mackerel, is a fish of the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

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 butterf ...

, found in tropical and subtropical waters of the

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the contin ...

from Japan south to Australia and

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...

, in the eastern

Pacific The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the contine ...

(

Hawaii Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only state ...

and

Socorro Island Socorro Island ( es, Isla Socorro) is a small volcanic island in the Revillagigedo Islands, a Mexican possession lying off the country's western coast. The size is 16.5 by 11.5 km (10.25 by 7.15 miles), with an area of . It is the largest ...

Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...

), and the

Indo-West 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 ...

: the

Red Sea The Red Sea ( ar, البحر الأحمر - بحر القلزم, translit=Modern: al-Baḥr al-ʾAḥmar, Medieval: Baḥr al-Qulzum; or ; Coptic: ⲫⲓⲟⲙ ⲛ̀ϩⲁϩ ''Phiom Enhah'' or ⲫⲓⲟⲙ ⲛ̀ϣⲁⲣⲓ ''Phiom ǹšari''; ...

, the

Persian Gulf The Persian Gulf ( fa, خلیج فارس, translit=xalij-e fârs, lit=Gulf of Fars, ), sometimes called the ( ar, اَلْخَلِيْجُ ٱلْعَرَبِيُّ, Al-Khalīj al-ˁArabī), is a mediterranean sea in Western Asia. The bod ...

, the Gulf of Oman and the Gulf of Aden, in surface waters down to . In Japanese, it is known as'' goma saba'' (胡麻鯖 sesame mackerel). It typically reaches in length and in weight.

Description

Blue mackerel are often mistaken for chub mackerel. In fact, blue mackerel were believed to be a subspecies of chub mackerel until the late 1980s. Though they are both in the same genus (''Scomber''), blue mackerel set themselves apart by differing structural genes than those of the chub mackerel. Other, more obvious, characteristics set these two apart, like the longer anal spine of the blue mackerel, and the amount of the first dorsal spines. Mackerels have a round body that narrows into the tail after the second dorsal fin, similar to a tuna fish.

Distribution and habitat

Throughout the lives of these mackerel, they tend to stay in areas within a few degrees of in tropical to subtropical waters. Off the east coast of North America, populations of mackerel have grown to over 2 million after being depleted in 1982. Blue mackerels can be found from the coast of North America, and as far as Australia and Japan.

Biology and ecology

The blue mackerel is known as a voracious and indiscriminate carnivore, devouring microscopic plankton, krill, anchovies, and dead cut bait, and striking readily on lures and other flies. When in a school and in a feeding frenzy, blue mackerel will strike at nonfood items such as cigarette butts and even bare hooks. They typically eat smaller

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 ...

fish. Due to their eating habits and their diurnal lifestyles, blue mackerel have evolved large eyes with higher sensitivity in their

retina The retina (from la, rete "net") is the innermost, light-sensitive layer of tissue of the eye of most vertebrates and some molluscs. The optics of the eye create a focused two-dimensional image of the visual world on the retina, which then ...

Lifespan

Incubation periods range from 3 to 8 days, growing shorter with warmer temperatures and longer with colder. In the East China Sea, blue mackerel spawn between February and May, when the water temperatures are ideal. In New South Wales, most spawning occurs offshore in waters in depth. The Eastern Australian Current can carry eggs and larvae away from the original spawning grounds, broadening the area in which blue mackerel are located. However, egg and larvae probability of surviving decreases the further they are carried by the current. A mature blue mackerel is considered to be over long. Mackerel can live up to 7 years and grow up to in length, but are most commonly found to be between 1 and 3 years of age. Counting the marks on otoliths determines the age of blue mackerel.

Human interactions

The blue mackerel can be flighty and difficult to catch, especially in estuaries and harbors. From 300 to 500 million tons of blue mackerel have been caught annually since the mid 1980s, without many fluctuations from month-to-month catches. Blue mackerel are caught for both commercial and private use, for food as well as bait for tuna and other fish. Blue mackerel are often used as cat food, but are also consumed by humans smoked, grilled, or broiled. While easy to fillet and skin, they are difficult to debone, and care must be taken to avoid damaging their soft flesh. Blue mackerel are also commonly used as meat binders. After being freeze-dried, the protein is extracted and put into other meat products to keep the meat and seasonings bound tightly together, allowing costs to be lowered and enhancing the flavor and texture of the product.

References

External links

* * * Fitch JE (1956
"Pacific mackerel"
''CalCOFI Reports'', 5 29–32. * Tony Ayling & Geoffrey Cox, ''Collins Guide to the Sea Fishes of New Zealand'', (William Collins Publishers Ltd., Auckland, New Zealand 1982) * California Department of Fish & Game, "California Finfish and Shellfish Identification Book" (University of California Press 2007) {{Taxonbar, from=Q1194328 blue mackerel Fish of the Pacific Ocean Fish of Japan Fish of the Red Sea Fish of Asia Fish of Oceania blue mackerel blue mackerel