What is Black tiger shrimp?

Black Tiger is in the category of the largest shrimp that is part of the Kuruma Ebi family and grows to be up to 30 cm. Black Tiger gets its name from the fact that it looks black before it is heated and has stripes like a tiger. The official name in Japan is “Ushi Ebi” but the reason is unknown. The Black Tiger is cultivated heavily in places like China, Vietnam, Indonesia, Thailand and India. It started to be imported from Taiwan in the 1980s to compensate when Japan’s shrimp consumption could no longer be covered by Kuruma Ebi. At the peak, it accounted for 40% of Japan’s shrimp imports. There is a strong impression of shrimp being imported, but small Black Tiger can actually be caught in Japan from Tokyo Bay southward.

Black Tiger has a strong sweetness and firm meat but maintains its plumpness even when cooked with heat. It is known for the red color that appears when heated. The appearance and texture when eating Black Tiger is said to be similar to Kuruma Ebi, which is known to be a shrimp of luxury, so it is a very popular shrimp in Japan. It is used not only as a sushi topping, but in a wide variety of dishes, such as for deep-fried shrimp or Tempura.

For sushi restaurants, shrimp that has been boiled and had the head and shell removed is imported in vacuum-sealed bags. Once defrosted, it can be used as a sushi topping without any further preparations. At conveyor belt sushi restaurants it was even once presented as Kuruma Ebi.

One problem with Black Tiger, which is the mainstream farmed shrimp, is that it has little resistance to illness, and cannot be farmed in the same place continuously. Therefore, Black Tiger farming volume has dropped and currently Vannamei Ebi (Whiteleg shrimp) is becoming a major force in shrimp farming.

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Revision date: July 9, 2021

What is Shiromiru?

The official name of Mirugai is “Mirukui”. The part of the Mirugai that is used as a sushi topping is the siphon that bulges out from the shell. The siphon is separated from the shell and then this is cut through longways, from top to bottom. One Mirugai can only produce four pieces of sushi. It is also nearly extinct from overfishing. While it can still be caught in the Seto Inland Sea and Mikawa Bay, there are fishing limits, which means it is an ultra-high-priced sushi topping.

However, most conveyor belt sushi restaurants offer Mirugai at reasonable prices. The topping on these is quite white. In conclusion, this shellfish is actually Shiromiru (also known as Namigai or Japanese geoduck) and is mainly found in Aichi and Chiba. As the name suggests, the siphon is larger than Mirugai and whiter (“shiro” means “white” in Japanese). There is a certain flavor that is peculiar to shellfish that live in sandy terrain, which some people like and some people hate. However, at less than half the price of Mirugai, it makes a decent substitute.

Unfortunately, the number of Shiromiru is also declining. Now, in order to fulfill demand, Pacific geoduck is being imported from places like Canada and the U.S. and is also called Shiromiru at the Toyosu Market.

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Revision date: July 8, 2021

What is Yamawasabi?

Horseradish is believed to have originated in Eastern Europe. It’s a cruciferous vegetable, alongside mustard, wasabi, cabbage, and broccoli. Horseradish is very fertile, and buds and roots will sprout just by cutting the root stock part to an appropriate size and soaking it in water. Once transferred to soil the roots will multiply quickly even without any other efforts.

In Europe horseradish is used as an ingredient for sauces or to accompany sausage and roast beef, or as a subtle seasoning for other dishes. In Japan most is used as an ingredient in processed foods such as wasabi powder or wasabi paste. Unlike wasabi, horseradish is characterized by its pure white root and strong spicy flavor. In Hokkaido horseradish is called “Yamawasabi” and is a common sight at home dinner tables.

Farming of Yamawasabi for food started in the Meiji era and settled in Hokkaido. Currently over 90% of the domestic production in Japan is accounted for in Hokkaido. While it is grown throughout Hokkaido, the vast Yamawasabi fields befitting Hokkaido are especially prevalent in Abashiri and Kitami.

In Hokkaido, Yamawasabi is eaten as an accompaniment to white rice. Grated Yamawasabi is sprinkled on rice and there are also jars of “Soy sauce-marinated Yamawasabi” sold as a normal item at supermarkets. Besides on rice, it is also indispensable to Hokkaido cuisine as seasoning for hiyayakko (cold tofu) and sashimi.

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Revision date: June 28, 2021

What is shirakawa?

Out of the five types of Amadai that live in Japan, Aka-amadai, Shiro-amadai and Ki-amadai are the three types offered in the markets. The main characteristics of Aka-amadai are its overall red body, the bright yellow color under the eyes and how part of its fin is a shiny cobalt blue color. Aka-amadai is called “Guji” in the Kansai region and is a vital part of Kyoto cuisine. Ki-amadai has the same silhouette and size as Aka-amadai, but the Ki-amadai has more yellow color in its face and tail fin. They tend to prefer sandy seafloors at depths of 30 to 300 m and live deeper than any other type of Amadai. True to its name, Shiro-amadai is a white color (Shiro means ‘white’) so is also called Shirakawa (which means ‘white skin’).

Shirakawa is considered to be the finest of the Amadai and can cost more than US $100 per kilogram. Aka-amadai costs around US $40 per kilogram. Shirakawa always ranks in the top three fish for market price. Shirakawa has more elasticity than the other two and has rich fat, making it perfect as sashimi or a sushi topping. The umami is so strong that even when served raw, the customer sometimes thinks it’s been prepared using kobujime. The fat between the meat and the skin is sweet and the skin is delicious in its own right, so it can even be eaten as sashimi with the skin left on. The famous production sites include Tsushima in Nagasaki Prefecture and Yawatahama in Ehime Prefecture. They are in season from autumn to winter. However, they say in a catch of 1,000 Amadai, you can only get one Shirakawa, so it is a rare item you won’t often see, even in a high-end sushi restaurant.

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Revision date: May 17, 2021

What is Karami?

Sashimi essentials such as wasabi, ginger, karami-daikon, etc., are collectively called “Karami”. Originally Karami was a type of Tsuma. From the mid to late Edo period, Karashi (mustard) was mainly used for karami in sashimi. Eventually, due to the influence of Edomae sushi, wasabi became the norm. For sashimi such as bonito and sardines, wasabi isn’t enough to offset the peculiar aroma. In some cases, it is better to use ginger, which works on the root components of the odor. These types of fish have the best flavor once spring has passed, and interestingly enough, wasabi is least prevalent in summertime, while ginger is in peak season. Mother nature seems to know what she’s doing.

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Revision date: April 5, 2021

What is Red caviar?

Not to belabor the point, but the following is dependent on the following. In Japanese salmon is referred to as “鮭” (sake/salmon) or “鱒” (masu/trout). The characters look different, but they are part of the same family and there aren’t clear biological categories to separate them into. Incidentally, in English the type that makes their way into the sea are called “salmon,” and those that remain in freshwater their entire lives are known as, “trout.” They are all considered to be part of the salmon family. Now, foreigners who know about Japan may imagine Japanese sake (the alcoholic beverage) when they hear the word “sake” so we spell sake/salmon as “shake”, which is close to the sound pronounced by Japanese people.

First of all, shake is mainly Chum salmon, caught in the seas near Japan. Masu caught in the seas near Japan are mostly Pink salmon (Humpback salmon) and Sakura masu. Masu caught in rivers and lakes are generally Char or Rainbow trout.

Now we finally get to the topic of this article, shake roe that has been removed from the ovarian membrane then salted or marinated in soy sauce is called ikura while masu roe is called masuko and they are clearly distinguished. This is because masuko can be bought at just 20-40% of the cost of ikura. However, the difference is really that each egg is smaller than that of ikura and in general people can’t taste a difference.

Over the past 10 years or so, the masuko made from the roe of Rainbow trout farmed in France and the masu farmed in Japan have been called ‘red caviar’ by manufacturers. Of course black caviar made from the roe of sturgeon and tobiko made from the roe of flying fish are distinctive. Certainly there is no problem in calling fish roe caviar according to the Product Labeling laws, but it’s extremely clear that they are only trying to get a higher price out of it.

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Revision date: March 9, 2021

What is Toro salmon?

You probably already know this, but “toro tuna” is not the name of a type of fish. “Toro” is the name of a fatty part of the tuna. The fat content and attributes of the belly side of the tuna are completely different from that of the dorsal side. Toro is the name of the part near the head, mostly on the belly side.

In the same way, there is no fish called “toro salmon”. Just like tuna, “toro” refers to the fatty part on the belly side of the salmon. It is also called “harasu” in Japanese. This is how the word is used at some scrupulous sushi restaurants. This description of “toro salmon” is correct.

Most salmon used at conveyor belt sushi restaurants is either trout salmon or Atlantic salmon. The reason this salmon can be served at the cheap price of US $1 or $2 per plate (2 pieces of sushi) is that these particular fish are all farmed and are available in bulk quantities from overseas. This salmon is mainly imported to Japan from Norway, Chile, Scotland and Canada.

Actually, the popular “toro salmon” topping is made from these imported items and the fat content is three times that of wild salmon. Feeding farmed salmon plenty of solid compounded feed that is high in protein and high in fat, turns the entire body to toro.

Salmon, which are born in freshwater and migrate downstream to the sea are called “sea-run fish” and they may be farmed in either seawater or freshwater. Trout salmon is “former” rainbow trout that was raised in a fish cage in the sea. In the wild, the sea-run rainbow trout grows up to 1 m in length, its body turns silver and the meat takes on a red color. The wild version of these are called “steelhead” and fetch a high market price, so they are not used in conveyor belt sushi restaurants.

Just like other aquaculture, salmon farming faces some difficult issues. It may surprise you that salmon is actually a white fish, originally. In the wild, the salmon meat gets a red color from feeding on crustaceans such as crab and shrimp that contain the red pigment astaxanthin. However, in the fish cages where the salmon are surrounded by nets, the food chain is also restricted. The compound feed would be plenty if the goal was only to raise bigger fish, but that results in a grey color or light yellow meat that doesn’t even resemble the salmon pink (orange?) that everyone wants and they don’t sell.

Therefore, when making the solid compounded feed, artificial coloring is mixed in. One of the colorings is called canthaxanthin. This is a synthetic chemical derived from petroleum. There is a color chart with 10 different, detailed levels of red coloring and buyers can even indicate which color they would like and the farmers can achieve it. It’s kind of like an industrial product that is being manufactured. Japanese people prefer a dark red color for salmon in the same way they do for tuna, so the coloring for Japan’s market is adapted to that.

When light is shone on wild salmon, the red coloring looks faded, but the light makes farmed salmon that have been fed coloring, look brighter. Artificial coloring is a necessity in farmed salmon and this is true for the trout salmon and Atlantic salmon that are used as the ingredients for toro salmon as well. All of the farmed salmon in circulation have been colored in this way, so much so that it wouldn’t be surprising if the insides of their stomachs were stained red. The flamingos at zoos also get their beautiful pink feathers from these chemicals.

Trout salmon is rainbow trout that has been farmed in the sea. On the other hand, rainbow trout farmed in freshwater is called Donaldson trout. Of all the large rainbow trout gathered at each location, those with small heads and fat bodies were selected and bred over many years to create this type. The objective of choosing a small head is to make more meat. They are characterized by their fast growth and while normal, farmed rainbow trout grow to about 30 to 40 cm, Donaldson trout grow up to nearly 1 m. The name is taken from the American who developed this variant.

The Donaldson trout is farmed throughout Japan and is used as toro salmon and aburi salmon at conveyor belt sushi restaurants. Since they are supplied directly to the processor (of the salmon) from the farmer without going through the market, they may be sold cheaper than the import price. Just like the imported salmon, this farmed salmon is also fed artificial coloring. There are also already new variants improved from the Donaldson trout being bred. Trout made from breeding Donaldson trout females and steelhead males are called Donaldson steelhead, for instance. They grow even faster.

Ample use of the latest biotechnology has been made in salmon farming and some of these technologies include creating young fish without functioning reproductive organs, “triploids” which means increasing the size of the fish up to triple and “all female populations” where males are converted into females. The triploid fish grow large in correlation to the lack of energy exertion. The objective of all-female populations is to get more masuko (ovaries). Masuko is used for the ikura (salmon roe) at conveyor belt sushi, and since the fish that the roe is harvested from have an inferior flavor, they are used for aburi salmon. Now, there are even triploid, all-female farm populations. No wonder the restaurants can serve a plate (2 pieces) of salmon sushi for US $1.

The simple phrase, “toro salmon” contains so much meaning.

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Revision date: March 8, 2021

Why is salmon so delicious?

When you put food in your mouth, the components that are dissolved by your saliva are called extract components. Extract components include mainly free amino acid and inosinic acid as well as organic-based components such as adenosine triphosphate-related substances, creatine and trimethylamine oxide. Extract components are important components that make up the flavor of foods.

When we looked up the extract component composition of the muscle of chum salmon, sockeye salmon, coho salmon and king salmon, which are all types of salmon, the component composition of chum salmon, sockeye salmon, coho salmon and king salmon are all similar.

The taste of fish is much lighter in comparison to the muscle meat of shrimp, crab and squid types of seafood. By combining extract components, shrimp, crab and squid flavors can be reproduced, but the relationship between the flavor extract components and fat in fish meat plays an important role in taste. The fat of fish gives it a rich flavor, illustrated by the fact that compared to the back meat of fish, the taste of the belly meat, which is abundant in fat to protect the organs, has a richer flavor.

The difference between the muscle of salmon and tuna is that salmon tends to have a lower inosinic acid content. Although not unique to salmon, the delicious taste of fish meat is related to the amount of inosinic acid and the amount of fat. Umami is mainly made up of inosinic acid is strongly related to fat and in case of inosinic acid content is high, it doesn’t feel “fatty” even with high-fat content. Instead, the fat makes it more pleasant and delicious.

On the other hand, when the inosinic acid content is low, a high-fat content doesn’t really translate into a pleasant taste. In the case of farmed fish, where high importance is attached to the weight of the fish when it is shipped, even if the fat content is high, if the inosinic acid level is low, then the fatty aspect does not translate into deliciousness, which is likely what leads to the opinion that the flavor of farmed fish is inferior to wild fish.

In the case of salmon variations, the inosinic acid content is low compared to tuna variations, and generally, the optimal amount of fat for delicious salmon is 4 to 6%. With tuna, the general idea is, the more fat, the more delicious, but this is not true for the taste of salmon.

Fat on animals that live above ground hardens when refrigerated. This creates an unpleasant waxy texture when eaten. However, as fish live in the frigid ocean waters, their fat doesn’t harden, even when stored at about -18℃. The most appealing aspect of salmon is thought to be that it goes well with shari (vinegared rice). The meat is soft and the fat has a low melting point, so it blends easily with shari and emits a sweetness when you bite. This is a sensation you won’t find with much other fish.

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Revision date: February 9, 2021

Nutritional and Functional components of unagi

According to Japan’s Fisheries Agency, based on their consumer’s behavior survey, Unagi (Eel) always ranks number one under, “Fish Japanese people want to eat.” The highest consumption of unagi throughout the year is in the hot summer months. Since long ago, Japanese people have been captivated by unagi as a food with high nutritional value and have loved it as a measure against heat fatigue. Here We would like to explain the nutritional and functional characteristics of unagi.

Unagi distributed domestically in Japan used to include European eel, but currently, it is mostly Japanese eel. In Japan, the overwhelmingly most popular way to eat unagi is “kabayaki”. Kabayaki mainly refers to a grilled fish cuisine in which unagi or anago (conger eel) is prepared by slicing open along the spine and removing the bones and guts, then skewering it, and grilling without any seasoning, steaming it (Some area, unagi is just grilled longer without steaming. This results in the unagi a little crispier and chewier) after that, and finally dipping it in a sauce made from a mixture of soy sauce, mirin, sugar, sake, etc.

The interesting thing is that the level of free amino acids, deeply related to flavor, is relatively low compared to other seafood. The fatty acid composition and volume don’t change even from heating and it also doesn’t significantly alter the free amino acids, so the flavor of unagi itself is light compared to the flavor of other kinds of seafood. Therefore, this is a big factor in Japanese people thinking of kabayaki sauce when they imagine the unagi flavor.

When the general components of unagi are compared with other fish (flounder, horse mackerel, sardines and bonito) and when they are compared with livestock (cattle, swine, chickens), unagi has the highest caloric content of 255 kcal per 100 g fortis edible parts and it also has the highest fat content (19.3 g per 100 g). Furthermore, it has significantly less fiber than beef or pork, so it is easier to digest. Collagen is present in all vertebrates, but the content is particularly high for eel. Of the minerals contained in the muscles, there is 130 mg calcium for every 100 g, which is much higher than other foods, even higher than milk. There are also abundant amounts of vitamins A, E and B in the meat. 50 g of kabayaki contains more than the recommended daily intake of vitamin A for an adult male and prevents oxidation of the fat, along with vitamin E. Especially high amounts of vitamin B1 are found in all seafood, and vitamin B2 and pantothenic acid contents are also relatively high. Meanwhile, the unagi is also known for having extremely high levels of vitamin A and folic acid in the internal organs.

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Revision date: February 9, 2021

What is the difference between denbu and oboro?

Oboro and Denbu look the same, and the ingredients are also pretty much the same. In other words, there are no clear differences between them, but what it is called differs depending on the restaurant’s policy and the locality. There are various theories for this, but there is no clear line distinguishing oboro and denbu.

Denbu (田麩) is mainly boiled white fish that is then loosened and made into fibers, then seasoned with sugar, mirin, salt, etc., then roasted until the moisture is gone. Some are colored with red food coloring (called sakura denbu) while others are left as the brown color similar to tsukudani. The appearance is as if only the fibers of the original ingredients remain. This is why it was written with the kanji “田夫” (the literal meaning of kanji: rice patty+husband). The word “田夫” means “someone from the countryside” or “rough-cut” and refers to the way the fish is turned into a coarse form by pulling the meat apart. It is also used as a coloring for chirashizushi, futomaki (large sushi rolls), bento boxes, etc.

On the other hand, Oboro (朧) is made by using a grinding bowl to break down the meat of shiba shrimp or white fish, then seasoning with sugar, mirin and salt before removing the moisture over low heat. Oboro is used for bara-chirashi, futomaki (large sushi rolls), etc., and is also sometimes used between the topping and shari (vinegared rice) in nigiri sushi. This gentle sweetness and the shrimp aroma are essential for Edo-style sushi. Making oboro is laborious work, so there are fewer and fewer Edo-style sushi restaurants that make their own oboro.

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Revision date: February 1, 2021

What is Fugu poison?

In most cases, Fugu (blowfish) poison is found in non-meat parts of the fish such as the liver, ovaries, stomach, intestine, skin and eyes. There are Fugu that do not contain poison in these parts, but most of the Fugu in the waters near Japan are poisonous. A mistake in preparations that allows the meat to touch the poison of the liver or ovaries results in immediate death. Therefore, the general rule is to only eat Fugu at restaurants with an expert licensed in Fugu preparation. Cases of poisoning by Fugu are nearly always a result of an amateur trying to prepare the fish.

The toxin in Fugu is a chemical substance called tetrodotoxin and even heat from boiling or frying can’t detoxicate it. Even Torafugu (Japanese pufferfish) that we find so delicious (we eat the meat, skin and testes) has poison in the liver, ovaries and intestines. The toxicity is said to be at least 1,000 times that of potassium cyanide. They say 10 people would die from the organs of a single Torafugu. In the case of Fugu poisoning, the first poisoning symptoms occur between 20 minutes and three hours after eating the Fugu. It starts with numbness in the lips, the tip of the tongue and fingertips. This is followed by headache, stomachache and severe vomiting. The victim will stagger when trying to walk. Soon they will experience sensory paralysis, speech disturbance and difficulty breathing, accompanied by a decrease in blood pressure. After that, the entire body becomes paralyzed and the victim can no longer move even a finger. Finally, they will fade out of consciousness and eventually both breathing and heartbeat cease, resulting in death. If the consumer doesn’t notice they are experiencing poisoning symptoms, they will surely die.

The strength of the toxin of the fugu also varies depending on the season. Even on an individual basis, some fish have toxins while others don’t. It’s not possible to determine this based on appearance, so it’s better to never eat the organs and eyes, which have a high probability of containing poison.

Fugu has already been successfully farmed and is on the market. No toxins have been found in this farmed Fugu. If farmed Fugu has no toxins, it’s only natural to question what factors generate toxins in wild Fugu and apparently it‘s a cumulative effect of toxins from the food chain. Fugu’s main sources of nutrition are starfish and shellfish. Starfish and shellfish accumulate poison in the body by eating zooplankton with vibrio attached to them. This vibrio creates poisons. Then, Fugu accumulates toxins in the body by eating starfish and shellfish that have toxins accumulated in their bodies. Therefore, farmed Fugu are raised on man-made feed that doesn’t contain Fugu toxins, and since they don’t ingest Fugu toxins and there is no bioconcentration, so the Fugu does not contain poison.

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Revision date: February 1, 2021

What is engawa?

Engawa has both a unique, crunchy texture and delightful fat distribution and is said to be the most delicious part of hirame.

But what exactly is engawa?

Engawa is the generally used name for the meat muscle that moves the soft ray of the dorsal and ventral fins of flatfish (such as hirame and makogarei). Most people in Japan think of the hirame version when they hear the word ‘engawa’.

To go into a more advanced level of detail, there are three types of muscles that move the dorsal and ventral fins in fish: the erector spinae, the depressor and the scalene muscles. These muscles are well-developed in fish that move their dorsal and ventral fins often, like flatfish and flounder. Actually, not all three of these types are always consumed. If we look at the way hirame and makogarei are cut for preparation, the slanted muscle is taken to be used for engawa while the erector spinae and depressor are left, affixed to the fin ray, etc. In other words, to be exact, engawa is the slanted muscle of the dorsal and ventral fins.

The unique, crunchy texture comes from the high content of collagen, which is a scleroprotein. “Kakushi boucho” is used to make the crunch pleasant and is one of the skills a sushi chef must perfect. The delicious flavor is related to the high amount of fat compared to body meat. There is also a sense of elegant sweetness. Only four pieces of engawa can be taken from a single flatfish, so it makes sense that foodies love it.

The name “engawa” comes from its resemblance to the unique veranda structure of Japanese-style homes. This veranda is called “engawa” in Japanese.

Incidentally, substitutions have become common at kaiten sushi (conveyor belt sushi) restaurants, and the topping is especially popular among women lately. So the question is, how is it possible to eat this valuable topping that is only rarely available at expensive sushi restaurants, so cheaply at kaiten sushi? Actually, Greenland halibut engawa and Kamchatka flounder engawa are used as substitutes to hirame engawa. The proof of this is in a menu that lists only “engawa” and not “hirame engawa”.

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Revision date: December 3, 2020

What is imitation crab?

One of the common ingredients of sushi rolls is imitation crab. In Japan this is called kanikama, in Europe, it’s called surimi and in the US it’s also called fake crab.

I’m sure everyone reading this has tried it before, but what is imitation crab made of?

It seems kanikama was invented in Japan. In the early 1970s, Sugiyo, a fish paste manufacturer, in a failed attempt to developed artificial jellyfish, ended up with a product that had a texture exactly like crab and shifted development to that instead.

The “kani” of “kanikama” means “crab”. “Kama” is an abbreviation of kamaboko, which is boiled fish paste, fish sausage, or fish cake. Its official name is “crab-like kamaboko”. The main ingredient is minced fish meat mashed into a paste. One of the whitefish used in Alaska pollack. But it contains no crab. Incidentally, there is actual crab in the kanikama sold in the US and Europe.

It has now become a staple not only in sushi rolls, but also in sandwiches or on baguettes and even on takeout salads. It’s become even more popular than it is within Japan.

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Revision date: June 22, 2020


What’s the difference between Tobiko and Masago?

The tiny red balls around the outside of the rice on California rolls are tobiko (飛び子). Specifically, they have salted roe of flying fish and are known for the plump, crunchy texture. This crunchy texture comes from the skin, which is relatively tough, even compared to other fish eggs. As the roe is made up of small eggs of only 1 to 2 mm, each one bursts as you bite, without leaving the outer skin in your mouth, so you can enjoy a nice texture that you won’t find with any other fish roe. Unlike the orange-colored tobiko sold in stores, natural tobiko has a pale golden color with a sense of transparency. Therefore, some processors have dubbed it “golden caviar”.

The main production areas are Indonesia and Peru, and in small quantities, Taiwan as well. The eggs from Indonesia are smaller than those from Peru. If you don’t like the skin remaining in your mouth then the Indonesian tobiko is recommended. Meanwhile, Peruvian roe has larger eggs and thus the skin is tougher, giving it an excellent firmness.

Freshly harvested flying fish roe gives you not only the satisfying popping texture like bubble wrap, but also a sense of the subtle aroma unique to fish roe. This combined with the saltiness of the sea gives you the same sort of umami found in tarako and ikura. Also, Tobiko sold at stores has even more added flavor. This is used for making hand-rolled sushi at home.

In fact, it is a registered trademark of a seafood processing company called Kanetoku, located in Hyogo prefecture, Japan. It isn’t hard to see that it’s an abbreviated version of the Japanese “Tobiuo no ko”.

Tobiko is rich in nutrients such as the minerals and vitamins potassium, phosphorus, vitamin E, vitamin C and niacin. Also, since it has a natural pigment composition called astaxanthin, which gives tobiko its bright color, it has antioxidative effects and is effective in strengthening the immune system. While Ikura has 272 kcal per 100 g, Tobiko only has 74 kcal per 100 g, adding a health factor to its charm.

What is flying fish?

Flying fish are found in the subtropical to temperate waters of the Pacific Ocean, Indian Ocean, and the Atlantic Ocean. They travel along the surface of the sea and eat zooplankton. Over 50 types of flying fish have been identified around the world. More than 30 of these have been identified in Japan, of which 4 types are used as food. Since the meat is white, low in fat, and has little odor, it is prepared in various ways such as sashimi, minced, grilled with salt, and fried. In Kyushu, flying fish is called “ago,” and it is dehydrated to be used as soup stock, called “dashi” in Japanese. Ago dashi has a refined and refreshing sweetness and a deep flavor, and it is considered to be on the higher-end of dashi stock.

The dorsal side of the flying fish is a vibrant dark blue, and the ventral side is silver The pectoral fin is considerably longer at about 30-40 cm long. It uses it pectoral fins to fly over the water’s surface to escape from its natural enemies, such as tuna Depending on the breed, it can fly an average of 200 m in one go. The larger the species, the longer distance it can fly and the longest can be up to even 600 m. Furthermore, the flying fish has no stomach and its other digestive organs are short and straight, which makes its body lighter and ideal for extended flight.

Flying fish contains a lot of a nutrient called Niacin which can help prevent hangovers. Additionally, it is rich in vitamin E, which works to prevent the oxidation of unsaturated fatty acids in the body, and as such is a good fish for preventing lifestyle-related diseases such as arteriosclerosis and myocardial infarction.

On the other hand, an orange-colored tobiko is often seen at conveyor belt sushi restaurants, etc., but this is the roe of a fish called capelin (カペリン), which is similar to shishamo smelt. A salted version of this is used for sushi rolls in the US and other places, where it is called masago. Compared to tobiko, the grains are smaller and the texture is a bit chewier. It is mainly rich in EPA (Omega-3 fatty acids) and collagen.

Masago (真砂子)” actually means “fine sand” and therefore is used for foods that depict that image. In other words, it refers to broken-up fish roe and doesn’t indicate a specific type of fish. Dishes made using capelin roe can be called masago, but please keep in mind that dishes with broken-up tarako or kazunoko are also called masago.

What is capelin?

The shape of capelin is very similar to shishamo smelt, but the scales are very fine, barely visible to the eye. The body is a bluish silver color with an average length of 12-16 cm, but can grow up to 20 cm.

It is found in a wide area from the Arctic Ocean to the frigid sea regions and also migrates to the Sea of Okhotsk on the coast of Hokkaido. The time they spawn depends on the region. The season for Canadian capelin is June to mid-July, and the season for Icelandic and Norwegian capelin is mid-February to mid-March.

They are also known as Komochi Shishamo (Shishamo with child) and are known to have a wonderful balance of fat and roe. Compared to shishamo smelt, they are leaner and have a lighter texture. Shishamo smelt is not caught in great numbers, so capelin started to be imported as a substitute for it for Japanese homes and izakaya (Japanese bar/restaurants).

Capelin rush to the coastal area in large groups to lays eggs on the sandy bottom of the beach during spawning season. The amount of eggs it lays at one time is about 5,000 to 6,000. It has spherical, adhesive demersal eggs with a diameter of around 1 mm. The eggs hatch around spring tide about 2 weeks after spawning The total length of larvae immediately after hatching is 4-5 mm, and it is thought that they leave the coastal area by utilizing waves at high tide and reach a total length of around 10 cm in the first year of life.

Capelin is a healthy fish that can be eaten in its entirety, and boasts 7 nutrients (DHA, EPA, calcium, zinc, potassium, vitamin B2, collagen). Moreover, since the sugar content is only 0.5 g per fish, about 1/3 of the amount normally contained in fish, it is perfect for those who are dieting.

If you come across wholesale Tobiko and Masago, it was likely purchased at the Toyosu Market. The reason for the ambiguous expression here is that you will rarely find nigiri sushi with tobiko or masago at sushi restaurants with counters. There may be some sushi restaurants that have tobiko or masago on their standard menu, but there are fewer than ten of those restaurants in Tokyo. In other words, in Japan, tobiko and masago are mainly used for kaiten-zushi (conveyor belt sushi) and izakaya restaurants.

Finally, we’ll let you in on a not-so-pleasant secret. Flying fish and capelin roe is actually a light yellow or beige color. However, you’ll find it in bright red, orange, yellow and lately even green or black. Of course, these are colored by either natural pigments or synthetic coloring. Furthermore, tobiko is sometimes mixed with the cheaper capelin or herring roe. Unfortunately, food fraud is common in seafood products that are consumed in high quantities.

We hope this information will be helpful.

Revision date: July 26, 2021

What makes a “good” sushi restaurant?

It is probably cutting fish just before serving. For a big size fish, keep its skin on the meat during the process of preparing and cutting into half, and at every serving use sogigiri* as much as customers eat. Protected by the skin, the fish flesh will expose to air for the first time as it is cut. The skin blocks the oxidation process significantly because the fat in fish centers right under the skin in general. Needless to say, even with any amazing fish, it loses flavor if the fat gets oxidized.

*Sogigiri-A method of cutting makes a slice thinner with a greater surface, by holding the knife diagonally and cutting in line with the cutting board. Usually used for white fish with firm flesh because it is easier to be eaten when served thin.

Hirazukuri-A method of cutting gives thickness to each slice so that the texture of sashimi can be enjoyable. This is used for akami like tuna.

We hope this information will be helpful.

Revision date: April 1, 2020