There are 18 species of eels in the world, among which there are four families of Japanese eel, perch eel, Celebes eel and short fin eel in Taiwan Province, but only Japanese eel is the most, and the other three species are rare. They have lived on the earth for tens of millions of years, but our understanding of them is only in recent decades. For example, 199 1 year only discovered its real spawning ground. Its sex was originally controlled by environmental factors and density. When the density was high and food was insufficient, it would become a male fish, and vice versa. In the rivers of Taiwan Province, because the number of eels is very small, most of them are female fish.

Eel fry can not be cultivated by artificial propagation, mainly because eels have a very special life history and it is difficult to simulate in artificial environment. Japanese eels grow up in freshwater rivers and become adult eels. In summer, they begin to migrate to the sea, that is, they swim from rivers to the ocean to lay eggs, which is just the opposite of the upstream migration of trout and salmon from the middle reaches of the ocean to the rivers to lay eggs. Its spawning grounds are thousands of kilometers away in the deep sea between the Philippines and the Malaysian Isles. Scientists found that this spawning ground was mainly because a lot of newly hatched larvae were collected here.

The larva of eel is about 6 cm long and weighs 0. 1 g, but its head is narrow and its body is tall, thin and transparent like a leaf, so it is called "willow fish". Its body fluid is almost the same as seawater, so it can be transported with ocean currents for a long distance with little effort. It takes about half a year for the Kuroshio current to drift back from the spawning ground and then back to the seashore of Taiwan Province, and it began to metamorphose into a slender and transparent eel line, also known as "glass fish", one month before reaching the shore. Therefore, every year 12- 1 month, fishermen will be busy fishing the eel line that is about to go back to the river on the coast near the estuary and sell it to farmers. After farmers bought it back and stocked it, the color slowly appeared, turning into yellow young eels and silver adult eels. Under natural conditions, the largest individual that can be caught is 45cm, and the weight is1600g.

Eels spawn and breed in the deep sea and grow in the fresh water environment. Fierce temperament, gluttony, active, staying up all day and coming out at night, strong optical rotation, like running water, so warm.

Adult eels grow fast, with a round appearance, like a cone shape, dark color and body-pleasing. In recent years, more artificial breeding has been carried out, and the meat is crisp. This fish is common all year round, but Xia Dong is the most delicious in two seasons. Eel is rich in nutrition, delicious, with less thorns and more meat, and has the functions of cooling off summer heat, nourishing and strengthening the body.

In addition, Monopterus albus, belonging to the family Compositae, also belongs to fish, also like a snake, without scales and yellow belly, hence the name Monopterus albus. Monopterus albus was born in a mud cave in a pond or on the bank of a freshwater river, so it is difficult to live without water. When caught, it is covered with saliva and foam. Monopterus albus is not only a delicious food with tender meat, but also has been recognized for its nourishing and medical functions since ancient times.

Eel refers to the general name of species belonging to the classification of Anguilla. Also known as eel, it is a kind of fish that looks like a long snake and has the basic characteristics of fish. In addition, eels have migratory characteristics similar to salmon.