Unagi (うなぎ) translates directly to “freshwater eel” but usually refers to the Japanese eel known as Anguilla Japonica. They are a popular food dish in Japan, referred to under the same name.
The Unagi is a long eel, with adults averaging approximately 1 meter in length, but known to grow as long as 1.3 meters. It has round eyes and mucus covers its entire body along with very small scales. It has a black back and a white belly, though other colors such as blue/green and grayish brown are both seen in different Japanese freshwater eels.
Despite being a well known breed of eel, much of its ecology is not known. There have been several studies trying to locate the spawning grounds. The thought originally was that the eels bred in the Philippine Trench near the Philippine Islands. However, a 2006 study at Tokyo University places the breeding ground near Guam.
They also believed that the eels laid their eggs in winter, but it appears that they may instead lay their eggs during the June and July months. There is also the possibility that these eels have changed their breeding patterns due to the shifts in weather. These same shifts appear to be causing a drop off in the population, as eggs are being pushed downstream too quickly to be fertilized.
Japanese eels have a great deal of minerals in their body. They have a lot of protein, making them popular amongst those that traditionally have low protein diets. It is also high in Vitamin A and Calcium. Unfortunately, it is also high in cholesterol and saturated fat, so it is not always considered a healthy option.
There are several ways to prepare the eel, but it is commonly seen in the following manners in Japan:
There are also several ways to cook Unagi. For example, people cook it over a fire because when the fat falls on the flames, the smoke that arises from the flame adds a strong flavor to the eel.
There is also a day dedicated to eating Unagi. In 2008, it was July 24th, but the date changes to be on the midsummer day of the Ox (doyo no ushinohi).