Ika Sushi
A Comprehensive Overview of Squid or Cuttlefish in Japanese Sushi Cuisine

The group of squid and cuttlefish is colloquially known in Japan as ika 烏賊(イカ) and includes numerous possible species that belong to the class of cephalopods.

Several hundred species of squid belong to the decapods (literally “ten-footed”). Of these, around 30–40 species are of considerable commercial importance and are often an important part of the national cuisine.^[1] Numerous species live in the waters around Japan, many of which are used in the preparation of food. In Japan, ika plays an essential culinary and economic role. They are eaten fresh, dried, smoked, fried or as an ingredient in sushi and sashimi. In the culinary world, ika is prized for its texture and mild flavor, which allows the squid to be used in a variety of dishes.

Before the spread of industrial refrigeration equipment and delivery logistics, ika was considered one of the classic cooked ingredients (nimono dane) for edomae sushi. Today ika is mainly used as a raw component, occasionally blanched or roasted variations are also encountered. When used as handformed sushi (nigiri), the topping (tane) is intentionally provided with distinctive cuts (kakushi bōchō) so that its shape fits better to the rice ball.

A gum-like consistency or an odd taste is a sign of inadequate freshness or that the type of ika used is less suitable for making sushi or sashimi. The translucent white meat of good quality ika is crisp, yet tender and pleasantly delicate and sweet in taste. When prepared as sashimi, in addition to the classic sliced preparation, there is also the option of cutting the meat into thin strips (ika somen). The arms are not normally used for sushi or sashimi, but are well suited for preparation on the grill (ika yaki) or cooked in hot water. Juveniles, whose general name is ko ika, are a speciality that is only available for a short period of time and are highly appreciated. Freshly grated wasabi, a piece of perilla leaf (shiso) or some citrus juice (sudachi) are very well suited as side dish or garnish.

Squid often presents a more direct and mild sweetness, sometimes accompanied by a subtle saltiness reminiscent of the ocean. Cuttlefish (kouika), on the other hand, tends to have a more delicate and nuanced sweetness, possibly with richer or nuttier undertones, and is generally perceived as less ‘fishy’ than squid. The fundamental flavor difference lies in the intensity and complexity of the sweetness, with cuttlefish often offering a more refined and less intrusive flavor profile than the straightforward mildness of squid.

The best time of the year is strongly dependent on the species and the region where they were caught. Especially imported commodity is available as frozen product all year round.

Japanese fishing for ika can be traced back to the Heian period (794-1185). Ika were presented to the imperial court during the Heian period (794-1185) according to the engishiki (延喜式), a book on laws and customs.^[3] At the beginning of the 2000s, Japan ceded its leading position to China, both in terms of total catch and consumption.

In the city of Hakodate in Hokkaido Prefecture, one of the largest ika fishing regions in Japan, the Pacific squid, known as surume ika in Japan, is a symbol of the city. Hakodate is not only known as an important port where surume ika is landed, but has also been famous for the ika odori, a dance, since the 1980s. The dance is themed around octopus and is the main feature of the Hakodate Harbour Festival (hakodate minato matsuri).

Ika can be found in all oceans of the world, from shallow to deep waters. There are no species found in fresh water. The group of squids is adapted to life in the open water, whereas cuttlefish prefer a habitat near the bottom. The total length varies depending on the species, from a few centimeters to several meters. Ika are mainly short-lived animals that live for one to three years depending on the species and typically die shortly after spawning. Ika-species have ten arms, two of which serve as tentacles, which are very mobile and serve to feel or grab the prey.

Squids are known being able to release a brown to grey-black fluid. This secretion is located in a muscle sack, which is colloquially called ink sack. If a squid feels threatened, it releases its secretion and can flee, hidden in the protection of the colored water cloud. When fleeing from an enemy, it moves at high speed by sucking seawater between its head and body and blowing it out of the funnel at once. Another characteristic of squids is that they can change the color of their body. This ability is used for various purposes such as camouflage and indirect communication.

The large-fin reef squid (Sepioteuthis lessoniana), whose name in Japanese is aori ika, is easily recognized by its large, rounded fins, which extend almost the entire length of its mantle. The origin of the name comes from the fact that the fins along the body resemble a horse's harness to protect it from mud, which is called aori 障泥 in Japan. The distribution extends from Japan to Australia and New Zealand and from Hawaii to East Africa, north to the Red Sea and south to Madagascar.

Aori ika is mostly caught near the coast and landed within a short time to be traded as fresh as possible. The bright and slightly transparent meat is highly appreciated in Japan for the preparation of sushi and sashimi, and is called by many the “King of Cuttlefish” (ika no ōsama). ^[3]

Until the mid-1990s, it was assumed that the varieties around the waters of Okinawa known as shiro ika, aka ika and ku ika belonged to the same species. Genetic studies have confirmed that they are closely related but independent species.^[4]

The golden cuttlefish, scientifically known as Acanthosepion esculentum, is called sumi ika 墨烏賊(スミイカ) in Japan. In a more professional or scientific environment, however, the species is called kouika. In addition to these two terms, the term maika is also used, which translates from Japanese as “real squid”. Sumi 墨(すみ) is the Japanese word for Chinese ink, an important component of traditional Japanese calligraphy. Young animals are known as shin ika, are only available for a short time in late summer and are highly sought after.

Sumi ika is a medium-sized squid that weighs around half a kilo and is considered an important part of Japanese cuisine. The golden band that runs along the base of the dorsal fin is striking. It is highly prized for its voluminous and tasty meat for the preparation of sushi and sashimi. The high content of free amino acids makes the meat particularly full-bodied and sweet.

Acanthosepion lycidas, also known as “Kisslip Cuttlefish”, is called kaminari ika in Japanese. This cuttlefish is highly regarded for its thick and tasty meat, and in the past was mainly referred to in the trade as mongō ika.^[5] Since the available supply of the catch landed could not meet demand, comparable species from Europe and Africa were imported into the Japanese market relatively quickly. More recently, the term has found a very inflationary use for many large imported squid species. As a result, comparable imported species of mongō ika now dominate the Japanese market, making kaminari ika a sought-after ingredient for sushi.

Apart from the species mentioned above, other species also find their way onto the counters of sushi restaurants. In Japan these are, among others, surume ika or imported common squid from Africa and Europe. In the U.S. and Europe, Humboldt squid, North American squid, common squid, and some other imported species are used predominantly as sushi toppings.

Squid and cuttlefish are of enormous importance to the global fishing industry, whose share, together with octopus, accounts for 7% of global fisheries.^[6] The selling price of ika is highly dependent on the species, quality, origin, supply, and demand. At the beginning of the 2000s, Japan relinquished its leading position to China, both in terms of total catch and consumption.

Since the advent of modern fishing in the 20th century, squid and cuttlefish has been fished in large quantities. Especially when fishing with trawl nets, the natural behavior of the animals is exploited. During the day, they gather above the sea floor. Bottom trawling aims to catch squid and cuttlefish species directly on the seabed, while pelagic trawling aims to catch shoals in medium-deep or bottom-near waters. Another method is fishing with drift nets, which hang vertically in the sea without being anchored to the bottom and drift through the open sea. Jigging involves luring larger species in particular to the water's surface at night with bright lights and then fishing from a boat with lowered lines.

Bottom trawling is criticized for causing considerable and irreparable ecological damage. Apart from the mechanical destruction of the bottom, fishing with nets dragged across the sea floor is not very selective and leads to high by-catches. The use of pelagic trawls and driftnets is less destructive, but also vulnerable to by-catches and designed to catch large quantities of the target species. Jigging, on the other hand, is much more selective without having a destructive effect on the habitat.