Japanese eel, Anguilla japonica. The Japanese eel and other eels live in fresh water and estuaries where they feed and grow as yellow eels for a number of years before they begin to mature and become silver eels that migrate to the sea spawn. The spawning area of this species is in the North Equatorial Current in the western North Pacific to the west of the Mariana Islands. The Japanese freshwater eel produces a fluorescent protein. This protein is the basis of a new test to assess dangerous blood toxins that can trigger liver disease. The Japanese eel is an important food fish in East Asia, where it is raised in aquaculture ponds in most countries in the region. In Japan, where they are called unagi, they are an important part of the food culture, with many restaurants serving grilled eel, which is called kabayaki. Eels also have uses in Chinese medicine. Aquarium photography