Beluga caviar (the roe of beluga sturgeon) is one of the most prized caviar varieties in the world. Since it can take up to 25 years for the animal to mature and start producing roe, this caviar is extremely rare, expensive, and extravagant. Beluga caviar beads are large, plump, and firm, with a color that can range from light to dark gray.

With a delicate, tender, and almost buttery flavor, beluga caviar can be eaten plain, allowing the complex layers to develop individually. It is also commonly combined with boiled potatoes, blini pancakes, or sour cream. Recently, wild beluga varieties have become critically endangered, partially due to wild poaching in the Caspian Sea, and strong sanctions have been introduced to limit the production, sales, and trade of this rare ingredient.

Tarako is a type of roe mostly harvested from Alaska pollock, but since the fish is closely related to cod, it is often labeled as cod roe. It is a type of salted roe with a light pink color, incredibly tender texture, and a mild and neutral flavor.

This roe can be eaten plain or incorporated into various dishes. It is often used as a topping on rice dishes and sushi, but it can also be cooked and used in sauces. When salted and marinated in spices, it goes under the name mentaiko.

Osetra is a prized caviar variety that is harvested from the Russian osetra sturgeon (Acipenser gueldenstaedtii). Osetra is native to the Caspian Sea, the Black Sea, and the Sea of Azov, including their river basins. Since it is a critically endangered species, it is rarely found or caught wild, and caviar is mostly harvested from farmed varieties.

Osetra has medium-sized eggs that often vary in color, flavor, and texture. They typically range from olive green to dark brown, sometimes with an appealing golden hue. Their texture is firm, while the flavor is usually briny, buttery, and distinctively nutty. 

Ikura (also known as salmon roe) are round, almost transparent salmon eggs, an unusual ingredient which is especially popular in Japan. After they have been removed from the sack, creating individual plump orbs, the eggs undergo the curing process which usually includes salt or brine.

During the Taisho period in Japan, which started in 1912, the Russians introduced the tradition of curing salmon roe to the Japanese. However, the Japanese adjusted the recipe to their tastes and started using fragrant soy sauces, sake, and rice wine for curing, giving the roe a deeper and distinctively Japanese flavor. 

Bottarga is an Italian delicacy consisting of a dense, salt-cured fish roe from tuna, mullet, or swordfish that resembles a petrified sausage, as it is first left to harden and is then coated with beeswax. It has a salty flavor with a silky texture.

Bottarga is often grated over pasta or egg dishes, although it can also be cut into smaller pieces, drizzled over with lemon juice, and served as an appetizer.

One of the essential ingredients in Japanese cuisine, katsuobushi or okaka refers to dried, fermented, and wood-smoked skipjack tuna. It is typically available pre-packaged in the form of delicate shavings which are used for imparting not only an intense umami flavor to various dishes but also the so-called kokumi - another taste sensation that can be described as heartiness and mouthfulness.

The production of katsuobushi is known to be complex and time-consuming, which contributes to its price tag. Also, the expensive skipjack tuna is sometimes substituted with its less pricey relative called bonito fish, which is why katsuobushi is often dubbed bonito flakes, and even though real katsuobushi is a far more superior product, both names are used interchangeably. 

Siberian sturgeon is mostly prized for its dark and glossy caviar. As the name suggests, Siberian sturgeon (Acipenser baerii) is mainly associated with Siberian rivers, lakes, and seas. The population is listed as endangered on the IUCN Red List, and caviar is mostly harvested from farm-raised sturgeons.

This caviar ranges from dark brown to black, and it typically has medium-sized, glistening beads. The flavor is earthy, nutty, buttery, and subtly sweet. It can be served on its own—preferably well-chilled—or paired with simple dishes such as the classic combination of blini pancakes and crème fraiche. 

Mentaiko or myeongnanjeot a term describing whole sacks of marinated Alaskan pollock roe, commonly eaten in Japan and South Korea. Quite often, it is mistaken for tarako (salted version), and since Alaska pollock is closely related to cod, the product is often labeled as cod roe.

The marinating process contributes to its savory, salty, and somewhat spicy flavor, which perfectly combines with its creamy texture. It originated in South Korea, where it has been enjoyed since the 17th century. After WWII, it became available in Japan, particularly among the traders in the region of Hakata, and soon it became a prevalent ingredient nationwide. 

This exceptional Greek delicacy, which was first referenced in writing in 1668, is made from whole roe of the gray mullet. The fish are caught in the shallow waters of the lagoons of Messolongi-Etolikos, Kleisova and Bouka between the estuaries of the Aheloos and Evinos rivers in western Greece.

The production of this so-called 'Greek caviar' takes time – once the fish are caught, the roe is gently removed, dried in their membranes, and then salted before they are separated and put into brine. Once they become pale and flat, they are hung to dry for several months.