The Japanese flying squid, Japanese common squid or Pacific flying squid, scientific name ''Todarodes pacificus'', is a

squid True squid are molluscs with an elongated soft body, large eyes, eight arms, and two tentacles in the superorder Decapodiformes, though many other molluscs within the broader Neocoleoidea are also called squid despite not strictly fitting ...

of the family Ommastrephidae. This animal lives in the northern

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 contine ...

, in the area surrounding Japan, along the entire coast of China up to

Russia Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-eigh ...

, then spreading across the Bering Strait east towards the southern coast of

Alaska Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S ...

and

Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tota ...

. They tend to cluster around the central region of

Vietnam Vietnam or Viet Nam ( vi, Việt Nam, ), officially the Socialist Republic of Vietnam,., group="n" is a country in Southeast Asia, at the eastern edge of mainland Southeast Asia, with an area of and population of 96 million, making it ...

Description

Adult squid have several distinguishing features. The mantle encloses the visceral mass of the squid, and has two fins, which are not the primary method of propulsion. Instead, the squid has a siphon, a muscle which takes in water from one side, and pushes it out the other side:

jet propulsion Jet propulsion is the propulsion of an object in one direction, produced by ejecting a jet of fluid in the opposite direction. By Newton's third law, the moving body is propelled in the opposite direction to the jet. Reaction engines operating on ...

. The squid has eight arms and two tentacles with suction cups along the backs. In between the arms sits the mouth, or beak. Inside the mouth is a tooth-tongue-like appendage called the radula. Squid have ink sacs, which they use as a defense mechanism against possible predators. Squid also have three hearts. The age of a squid can be determined on the basis of growth rings when additions are appended daily to the statoliths, balance organs in the back of the squid's head. This species of squid can weigh up to 0.5 kg. Mantle length in females can go up to 50 cm; males are smaller.

Habitat

The Japanese squid can live in water from 5 to 27 °C, and tend to inhabit the upper layers of the ocean. They are short-lived, only surviving about a year. The flying squid live in surface water of 100 m, but can go as deep as 500 m.

Life cycle

Within this year of life, the squid mature from their larval form, feed and grow, migrate, and at the end of their lives, congregate at the mating grounds, where they reproduce. Three subpopulations have been identified in Japanese waters. "The main group spawns in winter in the East China Sea, the second in autumn, west of

Kyushu is the third-largest island of Japan's five main islands and the most southerly of the four largest islands ( i.e. excluding Okinawa). In the past, it has been known as , and . The historical regional name referred to Kyushu and its surroun ...

, and the third, minor group in spring/summer in the

Sea of Japan The Sea of Japan is the marginal sea between the Japanese archipelago, Sakhalin, the Korean Peninsula, and the mainland of the Russian Far East. The Japanese archipelago separates the sea from the Pacific Ocean. Like the Mediterranean Sea, it h ...

as well as off northeastern Japan." "Their migration moves north, then south, tending to follow the surface currents. The squid tend to travel in large schools of more or less uniform size eaningthat it is often possible to follow the growth of cohorts from recruitment to spawning, although the earliest part of the life history is generally more difficult to study because the larvae are always

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 ...

and some are rarely caught". Squid generally only live one year because as soon as they reproduce, they die. Males mature first, and "transfer their spermatophores on the still immature females." Then, on the continuing journey south, the females "mature and spawn 300 to 4,000 small, elliptical or semi-spherical eggs." The squid migrate together, and lay all their eggs in the same area where they were born. The eggs hatch into larvae after only 102–113 hours (somewhere around five days), depending on the water temperature.

Diet

Squid are difficult to study individually in the lab, because "the animals appear to become stressed by isolation". However, the planktonic larvae are believed to feed on

phytoplankton Phytoplankton () are the autotrophic (self-feeding) components of the plankton community and a key part of ocean and freshwater ecosystems. The name comes from the Greek words (), meaning 'plant', and (), meaning 'wanderer' or 'drifter'. P ...

and zooplankton until they grow large enough to begin feeding on fish. When the squid mature more, they will eat mainly fish and crustaceans, but will also resort to cannibalism, especially when trapped in nets together.

"Flying"

Flying squid have been observed to cover distances as long as 30m above the surface of the water, presumably to avoid predators or save energy as they migrate across vast expanses of ocean, uniquely utilizing jet-propelled aerial locomotion.

Predators

Many vertebrate predators depend heavily on squid, which is second only to

krill Krill are small crustaceans of the order Euphausiacea, and are found in all the world's oceans. The name "krill" comes from the Norwegian word ', meaning "small fry of fish", which is also often attributed to species of fish. Krill are consid ...

as a food source in the Southern Ocean. Animals such as the grey-headed albatross and the sperm whale (the largest of the toothed whales) feed almost entirely on squid. Other predators include dolphins, seals, baleen whales, and rays.

Fishery

Major fishers of the Japanese flying squid are mainly Japan (with the highest usage and catch in tons), the Republic of Korea (with the second-greatest catch), and relatively recently, China. Within all countries where it is being fished, the squid is also exported to many other countries for consumption, with the United States being a top importer. Japan is the largest consumer (mainly due to

sushi is a Japanese dish of prepared , usually with some sugar and salt, accompanied by a variety of , such as seafood, often raw, and vegetables. Styles of sushi and its presentation vary widely, but the one key ingredient is "sushi rice," also ...

) and exporter of the Japanese flying squid. (See also

surume Dried shredded squid is a dried, shredded, seasoned, seafood product, made from squid or cuttlefish, commonly found in coastal Asian countries, Russia, and Hawaii. The snack is also referred to as dried shredded cuttlefish. History and origins ...

) Japanese flying squid are caught all year round, but the largest and most popular seasons are from January to March, and again from June to September. Gear used to catch them is mainly line and hook, lift nets, and gill nets, the most popular method being hook and line used in jigging. Current data on the Japanese flying squid show that, throughout the years, the rate of capture has fluctuated, with capture increasing and decreasing during 1970s to the 1990s. Since 2010, catches have ranged from 570,427 tonnes in 2010 to 351,229 tonnes in 2012. The fishing techniques used, mainly the hook-and-line methods, coupled with fishing at night to attract the squid, seem to allow for minimal by-catch. Other systems, such as gill nets, are usually less specific in what they catch, although some technological advances have involved larger openings to allow smaller animals to pass through.

References

External links

Japanese flying squid facts
from squid-world.com {{Taxonbar, from=Q780352 Squid Molluscs of the Pacific Ocean Marine molluscs of Asia Marine molluscs of North America Molluscs of Oceania Western North American coastal fauna Molluscs of Japan Molluscs of the United States Invertebrates of Vietnam Fauna of Alaska Molluscs described in 1880