The first thing to consider is that the word sushi means raw fish preserved in vinegar and rice, the most common error is named sushi to the nigiri and everything else, there are even people and restaurants who dare to call California rolls to the maki... Something truly unforgivable.
As a note, you should not pluralize, when we refer to several pieces of sushi such as nigiri, we must say, I ate some "nigiri" very good, and no, I ate some "nigiris" attention not with U (Niguiri). It is also noteworthy that sometimes sushi can be found written with Z, is not misspelled, it really depends, when we refer to sushi or named as such is written with S, but if we refer to the kind of sushi is written with Z, example: I ate a Nigiri-Zushi or I would like to eat a good Sushi.
Always remember that sushi is simply a generic term, and at all times should say when ordering a dish, the variety and then the type of sushi.
There is a legend that says, each type of sushi comes from a specific region of Japan, hence the different types and their respective characteristics, however, the term sushi encompasses all variants of this mixture of raw fish and rice. Although there are times when the fish is not merely crude as in the case of shrimp, eel or the alternative of combinations such as tamagoyaki (Japanese omelet).
Now it is very difficult to say exactly when it appeared the sushi for the first time in Japan, but the strongest theories say around 1800 and was regularly consumed some types of sushi as we know it today, although by then we could say that arose two different styles, the Kansai and Kanto.
In the region of Kansai, near Osaka, in the western part of Honshu, traders served small packets of rice mixed with various ingredients and seasonings, mainly to cooked ingredients and presented in various styles. And as in the Edo region surrounding Tokyo was easier to get good seafood, sushi was served like a piece of raw fish on a little finger of rice with vinegar (nigiri), hence it is classified as Kanto, which in once he gave fame to sushi also called Edomae-sushi.
Since then the sushi has evolved considerably, we could say the sushi today is Westernized, at the point that took important consideration in the government of Japan a couple of years ago, they wanted to establish protocols to identify truly Japanese restaurants all around the world in order to be able to ensure that they transmit their real traditional food culture and not call in question their identity. Particularly I think that is a serious error, there is no doubt that one way or another are collaborating to the spread the Japanese traditions and creating a daily number more adherents to sushi and thereby introduce many people to delve more about their culture.
However, we could say that the sushi is classified by type of preparation, here are some of the best known in the West.
Nigiri zushi: there is a conceptual error regarding this type, as commonly known as "sushi" (remember, sushi is any combination of raw fish with rice) but actually is "nigiri" this is molded by hand, it is one finger of rice (shari) topped with a fine cut of fish (neta). They seem simple but are the most difficult to develop. Its name means kneading, that is how it is really done. They are usually served in pairs number of pieces.
Bara-zushi: It is very similar to Chirashi-zushi, the difference is that this type of sushi cthat mix together assorted cuts of fish, shellfish and vegetables, ends up being a kind of (and I say this with all due respect) a salad on a rice bed, was very extravagant.
Chakin-zushi: Fukusazushi is very much like, it is also wrapped in tamago or tortilla, the difference is that instead of having rectangular shape, it is circular, usually it is tying it somehow with a nori ribbon. The Chakin is a fabric that is used to purify the equipment during the tea ceremony.
Chirashi-zushi: Is nothing more than cuts of raw fish on a base of sushi rice, sometimes accompanied with other ingredients, literally means spread sushi, it is often confused with the barazushi.
Fukusa-zushi: Fukura is a special paper used to wrap very special gifts, hence its name, as this type of sushi is wrapped similarly to a gift, but obviously rather than the paper, a tamago (Japanese egg omelette) is used, usually rectangular shape and are very delicious.
Bo-zushi: also known as trunk sushi, and is nothing more than a whole fish fillet cut, usually saba (mackerel), which is arranged above a trunk of rice over a sheet of nori, is a kind of hybrid between a nigiri and maki, it is shaped with makisu and then cut so that each piece of sushi look like a crescent moon.
Inari-zushi: Also known as filling sushi, it is a kind of deep fried tofu small bag, filled with sushi rice and other ingredients. Its name comes from the goddess Inari which loved products made with rice.
Oshi-zushi or Hako-zushi: This sushi is the Kansai style, is no more than a block of rice, pressed into a wooden mold, the mold bottom called oshibako with the filler is coated, it is placed over rice and press the mold lid to create a compact and rectilinear block, which is subsequently cut into squares or slices. Oshi literally means pressing and Hako box.
Nare-zushi: is very common in the Edo period (1603-1868) and fermented sushi very rare to find nowadays, was the precursor to nigiri-zushi, the pieces of whole fish and salt were left clean and dry in barrels, later on they press them with a special stone marinade, procedure was repeated up to several months, this type of sushi is made without rice, only the fish cuts into thin slices is used and is sometimes accompanied with vegetables.
Gunkan: (Funamori) as its Japanese name suggests is the battleship sushi is a sushi oval and is made by kneading rice similar to nigirzushi, the difference between them is wound or wrapped with a strip of dehydrated seaweed or nori, to form a bowl of rice based filling it ends usually with roe.
Maki: Means roll, this variety of sushi is done by extending the rice on sheets of dried seaweed or nori, with fish or in the case of futomaki with a mixture of several ingredients, all with the help of makisu (bamboo mat). The roll is cut into portions of about two inches thick, usually eight pieces. During the festival of Setsubun, is tradition to eat makizushi without cutting, in its cylindrical shape.
There are several types of maki, among them are:
Hosomaki: a roll with rice inside and seaweed outside, usually cut into 6 pieces, in some restaurants the cut in 8 to monetize. It is believed that these are the origin of the rolled sushi, usually a single ingredient for stuffing, such as tuna, cucumber, salmon, is used. His name is because Hosoi means narrow, as is the roll itself.
There are several hososmaki, depending on its ingredients, the most popular are:
- Ana-kyu-maki (Eel and cucumber)
- Chutoro-maki (Top of tuna belly)
- Kaiware-maki (Daikon sprouts)
- Kampyo-maki (Japanese pumpkin)
- Kappa-maki (Cucumber)
- Natto-maki (Fermented beans or soy beans)
- Negitoro-maki (Chive and tuna)
- Oshinko-maki (Daikon)
- Otoro-maki (Fatty tuna)
- Sake-maki (Salmon)
- Tekka-maki (Tuna)
- Tekkappa-maki (Tuna and cucumber)
- Umejiso-maki (Japanese plum and Shiso
Futomaki: A roll with rice inside and seaweed outside, also usually cut into 8 pieces. It is similar to the hosomaki, only a little bigger, because for them together various ingredients used for the filling, such as tuna with salmon, cucumber, avocado, etc. Its name is because it is a very big roll, in Japanese Futoi means thick.
Uramaki: Is also a roll, but with nori inside and rice outside (inside out roll opposite side in Japanese), the California roll is a Uramamki also comes cut into 8 pieces.
Temaki: Actually hand roll or also called sushi cone, is part of the traditional Japanese cuisine, however, in the West merges with various ingredients, including cream cheese, forming a kind of cone. The word Te, literally means hand. In Japan the customer elaborates temaki on the table, restaurants serve only the ingredients and everyone does it to his own taste.
You may read the different types of sashimi in this post.