Tobiko is the Japanese

Japanese language

is a language spoken by over 130 million people in Japan and in Japanese emigrant communities. It is a member of the Japonic language family, which has a number of proposed relationships with other languages, none of which has gained wide acceptance among historical linguists .Japanese is an...

 word for the flying fish roe

Roe

Roe or hard roe is the fully ripe internal egg masses in the ovaries, or the released external egg masses of fish and certain marine animals, such as shrimp, scallop and sea urchins...

 used to create certain types of sushi

Sushi

is a Japanese food consisting of cooked vinegared rice combined with other ingredients . Neta and forms of sushi presentation vary, but the ingredient which all sushi have in common is shari...

. Tobiko is sometimes used as an ingredient in California roll

California roll

The California roll is a maki-zushi, a kind of sushi roll, usually made inside-out, containing cucumber, crab meat or imitation crab, and avocado. In some countries it is made with mango instead of avocado...

s.

The eggs are small, ranging from 0.5 mm - 0.8 mm. For comparison, tobiko is larger than masago (capelin

Capelin

The capelin or caplin, Mallotus villosus, is a small forage fish of the smelt family found in the Atlantic and Arctic oceans. In summer, it grazes on dense swarms of plankton at the edge of the ice shelf. Larger capelin also eat a great deal of krill and other crustaceans...

 roe), but smaller than ikura (salmon

Salmon

Salmon is the common name for several species of fish in the family Salmonidae. Several other fish in the same family are called trout; the difference is often said to be that salmon migrate and trout are resident, but this distinction does not strictly hold true...

 roe). Plain tobiko has a red-orange color, a mild smoky/salty taste, and a crunchy texture. Sometimes tobiko is colored with wasabi

Wasabi

, also known as Japanese horseradish, is a member of the Brassicaceae family, which includes cabbages, horseradish, and mustard. Its root is used as a condiment and has an extremely strong flavor. Its hotness is more akin to that of a hot mustard rather than the capsaicin in a chili pepper,...

 (green), yuzu

Yuzu

The yuzu is a citrus fruit and plant originating in East Asia. It is believed to be a hybrid of sour mandarin and Ichang papeda...

 (pale orange) or squid's ink (black).

Masago, i.e. Capelin roe, is frequently substituted for tobiko due to its similar appearance and flavor.

Tobiko is also used in the creation of other Japanese dishes

Japanese cuisine

Japanese cuisine has developed over the centuries as a result of many political and social changes throughout Japan. The cuisine eventually changed with the advent of the Medieval age which ushered in a shedding of elitism with the age of shogun rule...

.