An Introduction to the Habits, Characteristics and Food Value of the Lamprey

The lamprey, also known as the seven-gilled lamprey or seven-star fish, is an ancient jawless fish and is not a true eel. It gets its name because it has one eye on each side of its head and seven gill openings, making it look as though it has eight eyes. This group of animals has a long history of survival on Earth and is often regarded as an important living fossil for studying the evolution of vertebrates.

In appearance, the lamprey has a slender, cylindrical body with smooth, scaleless skin, and its dorsal fin extends along the rear part of the body and connects with the caudal fin. Its mouth has no upper or lower jaw, but instead forms a round suction disc lined with keratinous teeth. Some species live as parasites as adults, using the suction disc to attach to other fish and scraping off the host's blood and body fluids; some species do not feed as adults and die naturally after completing reproduction.

Lampreys are mainly distributed in the temperate waters of the Northern Hemisphere, and most species go through both freshwater and seawater stages during their lives. The larvae live in the muddy and sandy bottoms of rivers, filter-feeding on organic debris in the water. After several years of metamorphosis and development, some swim downstream to the sea to grow, and after reaching sexual maturity they migrate back to rivers to spawn. Different species have relatively high requirements for water quality and spawning environments, so populations in some areas are easily affected by environmental changes.

It should be noted that although the lamprey has the character for eel in its name, it is only distantly related to what people commonly call the eel, that is, the river eel, which belongs to the jawed fishes and has completely different farming and migration patterns. In some regions, lampreys have a tradition of being eaten; their bodies contain only cartilage and no hard bony spines, and their flesh is soft and tender. However, wild resources are limited, and some species have been included in protected categories, so catching and eating them must comply with local relevant regulations.