Surprising Facts:Nigiri Sushi & Gunkanmaki: A Flavor Journey Through 70 Varieties

A Culinary Journey of Nigiri Sushi Beyond Fish

Seafood like shrimp, crab, squid, octopus, abalone, and scallops are also popular in nigiri sushi. These ingredients offer a different texture and flavor compared to fish nigiri.

Sweet Shrimp (Famous / Low Price Range)

Known scientifically as Beryx splendens Lowe and belonging to the snow crab family, Sweet Shrimp inhabit the deep-sea floors of the North Pacific from the northern Japanese coast to the Sea of Okhotsk, the Bering Sea, and as far as the west coast of Canada at depths of about 200-700 meters. While not sweet during their life, a post-mortem activation of digestive enzymes breaks down amino acids, creating sweetness. The peak season is from November to February, when their sweetness is most pronounced.

Kuruma Shrimp (Famous / Medium to High Price Range)

Kuruma Shrimp (scientific name: Marsupenaeus japonicus) is a representative shrimp species, with wild ones being rare and most being farmed. The peak season is from October to January, characterized by a rich sweetness and a crisp texture. They are low in fat and calories, used either raw or boiled in nigiri sushi.

Botan Shrimp (Rare / High Price Range)

The peak seasons for Botan Shrimp (scientific name: Pandalus nipponensis) vary between males and females, with spring for males and autumn for females. This shrimp, primarily caught on the Pacific side, is so pricey that it is only seen in high-end sushi restaurants. Its flesh is elastic and melts in the mouth, offering a sweet and luxurious taste.

Mantis Shrimp (Famous / Low to Medium Price Range)

Although similar in shape, Mantis Shrimp (scientific name: Oratosquilla oratoria) are a different crustacean species from shrimp. They have a softer and milder flesh than shrimp but are known for their intense umami. Typically about 20 cm in size, mantis shrimp possess very strong front limbs (mantis claws) which are popular as a delicacy to accompany drinks.

Snow Crab (Famous / Medium to High Price Range)

Snow Crab (scientific name: Chionoecetes opilio) is a medium-sized crab caught mainly in the Sea of Japan and known by various local names like “Matsuba Crab,” “Echizen Crab,” and “Kano Crab,” depending on the region. Hyogo and Tottori prefectures are the main producers, where it is branded as a luxury product under names like “Kasumi Crab” and “Shibayama Crab.” The peak seasons differ for males (November to March) and females (November to January). Compared to other crabs, its flavor is more subtle, but it can be enjoyed in various dishes such as hot pots, sushi, and sashimi. When used in nigiri sushi, the crab leg meat is typically placed on top of vinegared rice.

Bigfin Reef Squid (Famous / Medium Price Range)

Bigfin Reef Squid (scientific name: Sepioteuthis lessoniana) is most in season from May to August. Known for its elastic texture and sweet flavor, the catch of squid species in Japan peaked at 750,000 tons in the 1980s but has recently declined to about one-tenth of its peak. As a result, related species are now imported from Southeast Asia and America.

Japanese Flying Squid (Famous / Low Price Range)

Japanese Flying Squid (scientific name: Todarodes pacificus) is the most consumed squid in Japan. Over half of the domestic catch comes from Hokkaido and Aomori Prefecture, with stable prices and flavors thanks to widespread capture across other regions. This squid is versatile, used in grilled dishes, stews, salted foods, dried foods, nigiri sushi, and sashimi. It is particularly known for its sweetness and the delicious flavor of its innards (wata).

Octopus (Famous / Low to Medium Price Range)

Common octopus is in season from November to January, known as a premium octopus with a firm texture and rich umami. The webfoot octopus mainly has its peak season in summer but is caught year-round, known for its softness and sweetness. Octopus (scientific name: Octopus vulgaris Cuvier) can be used boiled or raw in nigiri sushi, offering an elastic texture in both forms, with raw octopus being particularly sweet.

Oyster (Famous / Low to Medium Price Range)

The main types of oysters (scientific name: Crassostrea gigas) circulated in Japan are as follows: the rock oyster, in season from May to August, is large in both shell and flesh, known for its creamy flavor and available both wild and farmed. The Pacific oyster, farmed almost 100%, peaks from December to February, known for its firm flesh and balanced flavor. Both types of oysters for raw and cooked consumption contain the same nutrients, but those for raw consumption meet the standards of the Food Sanitation Law, reducing the risk of food poisoning.

Turban Shell (Famous / Medium Price Range)

Turban Shell (scientific name: Turbo sazae) is a rugged, conical gastropod that can grow up to 20 cm in shell height. It is a popular edible shellfish in Japan, with those grown in rough open seas featuring more spines and those from inner bays having fewer. Its peak season spans from spring to early summer, with main production areas in Mie, Chiba, Nagasaki, Yamaguchi, and Ishikawa Prefectures. However, its flavor is consistent throughout the year, and it can be enjoyed regardless of the season. It is known for its crunchy texture and seaside aroma.

Abalone (Famous / High Price Range)

Abalone (scientific name: Haliotis discus) is a type of gastropod, with the main types consumed in Japan being black abalone, Ezo abalone, and Madagascar abalone. Slow-growing, taking over five years to reach 11 cm, abalone is a very expensive ingredient. The main production areas are the Boso Peninsula, Izu Peninsula, Ise-Shima, and Wajima, with its peak season in the summer months from July to September. Its crunchy texture is a highlight, and it is used in various dishes including sashimi, sushi, and even steaks.

Whelk (Famous / Low Price Range)

Whelk (scientific name: Neptunea polycostata Scarlato) is a type of gastropod caught in the cold waters of Hokkaido and the Tohoku region. It is known for its crunchy texture, similar to but sweeter and more flavorful than abalone. The peak season is from early spring to early summer. Enjoyed raw, it offers a distinct seaside aroma, and when cooked, its sweetness and umami are enhanced.

Torigai (Famous / Medium to High Price Range)

Torigai (scientific name: Fulvia mutica) is a bivalve that inhabits the coasts of East Asia, including Japan. The name comes from the bird’s beak-like shape of its meat. It is primarily caught in Tokyo Bay, Mikawa Bay, Ise Bay, and the Seto Inland Sea, with the peak season varying by region. On the Pacific side, the season peaks in early spring, and on the Sea of Japan side, in summer. Torigai is particularly used for sashimi and sushi, known for its chewiness yet tender texture and subtle sweetness. It retains its taste even when frozen and is utilized throughout the year, though it holds high market value as a fresh,luxury ingredient.

Ark Shell (Famous / Medium to High Price Range)

Ark Shell (scientific name: Anadara broughtonii) inhabits the muddy bottoms of bays and shallow seas across Japan, Korea, China, Taiwan, and the Russian Far East. Its distinctive red blood is due to the presence of erythrocruorin, which also gives the ark shell its name. The shell can reach up to 12 cm in length and 9.6 cm in height. It is especially used in sushi and sashimi, with imports from China and Korea dominating the market recently.

Scallop (Famous / Medium to High Price Range)

Scallop (scientific name: Mizuhopecten yessoensis) is primarily harvested in the northern parts of the Tohoku region, such as Aomori and Iwate prefectures, and Hokkaido. This bivalve can grow up to 20 cm. Scallop has two peak seasons: from May to August, when the muscle grows significantly, and from December to March, when the roe develops. Scallops are used in a variety of dishes, including sashimi, sushi, stews, sautéed in butter, soups, and fried, with high demand for raw consumption.

The Culinary Journey of Gunkan Maki

Gunkan maki is a type of sushi where vinegared rice is wrapped in seaweed and topped with small fish, shellfish, or fish roe. This style enables the enjoyment of seafood that is too delicate or difficult to handle in regular nigiri sushi. Its appearance, resembling a battleship, is the origin of its name “Gunkan” (battleship).

Ikura (Famous / High Price Range)

Ikura, or salmon roe (scientific name: Oncorhynchus keta), primarily consists of salmon family eggs and is a delicacy not very familiar outside of Japan. Salmon roe is considered more premium than trout roe and is about 30-40% more expensive. The best season for ikura is from September to November, with major production areas including Hokkaido, Niigata, and Miyagi. These fish eggs are typically marinated in soy sauce and served as gunkan sushi, known for their unique texture and flavor, making them a staple in gunkan sushi.

Tobiko (Famous / Low Price Range)

Tobiko, or flying fish roe (scientific name: Cheilopogon agoo), is characterized by its vivid orange color similar to ikura, with each grain about 1 mm in size. It is best from early spring to summer, known for its light, low-fat flavor. Tobiko provides a delightful crunchy texture due to its smaller eggs, making it a frequent and affordable choice in sushi bento boxes.

Shirako (Rare / Medium Price Range)

Shirako, or milt (scientific name: Gadus chalcogrammus), specifically from cod, is renowned for its creamy texture that melts in your mouth. The peak season for fresh shirako is from January to February when it is abundant and less watery. Commonly enjoyed with ponzu sauce, it is also used in hot pot dishes.

Uni (Famous / High Price Range)

Uni, or sea urchin (scientific name: Hemicentrotus pulcherrimus), involves consuming the gonads, offering a rich flavor distinct from fish, shellfish, or roe. This makes it especially popular in gunkan sushi and a luxury sushi item. The best season for uni varies by type and location. Purple sea urchins, known for their white, delicate, sweet flavor, are best from June to August. Bafun uni, rich and flavorful, is harvested year-round in various parts of Hokkaido. Kitamurasaki uni is collected in Aomori and peaks from autumn to the end of the year, known for its rich flavor. Ezo bafun uni has a similar taste and its peak season in Hokkaido is around March.

Ankimo (Rare / Medium Price Range)

Ankimo, the liver of the monkfish (scientific name: Lophius litulon), is steamed and known as the “foie gras of the sea” due to its rich flavor. The best season for ankimo is from December to February, when its flavor is most intense. In Oarai, Ibaraki, famous for its production, monkfish dissection shows are popular. These fish can weigh over 10 kilograms, and a unique method called “ankou no tsurushi-giri” has been developed for their dissection, becoming a seasonal tradition.

Shirasu (Rare / Medium Price Range)

Shirasu are the juvenile stage of the Japanese anchovy (scientific name: Engraulis japonicus). Fresh shirasu sushi is very rare due to its rapid loss of freshness. During the fishing ban period, it is not possible to enjoy fresh shirasu. In production areas like Awaji Island in Hyogo and Shizuoka, the peak seasons are spring and autumn, with the tastiest period from June to September when the water temperature is higher.

Firefly Squid (Famous / Low Price Range)

Firefly squid (scientific name: Watasenia scintillans) inhabit the deep sea and are known for their multiple photophores, glowing a mystical blue-white. The season peaks from March to June, with a significant catch starting on March 1st in Toyama Prefecture. During this season, firefly squid are larger and have excellent freshness. Their firm texture and increased sweetness make them particularly delightful. When boiled, their bodies become rounded and glossy.

Crab Miso (Rare / Medium Price Range)

Crab miso, a brown paste collected from the shell of the crab (Chionoecetes opilio), corresponds to the liver and pancreas of the crab and is known for its rich flavor. The peak season varies by type of crab: snow crab from December to February, zuwaigani from April to July, and king crab from April to May and September to October. Eating straight from the cracked shell with a spoon is traditional, and it is also served as gunkan sushi in conveyor belt sushi restaurants.