To identify wild or farmed eels, you must first understand the category of eels. Eels are divided into multiple families such as conger eels and eels, and there are many species. There are more than 50 species of conger eels alone, and there are also about 10 species of eels. Conger eels live in the sea and cannot survive in fresh water. Eels spawn in the sea, and when the young mature, they return to live in freshwater rivers. The live eels on the market are mainly eels, because conger eels cannot be raised in fresh water, and the ones sold on the stalls are dead.
Eels are also called white eels. They have a slender body, a nearly cylindrical front part, and a flattened back part. The dorsal fin, anal fin and caudal fin are connected. They have scales, but they are buried under the skin and are very small. They can only be seen with a microscope. There is a lot of mucus on the body, the upper part of the body is gray-black, the upper side edge is green, and the lower body is white. They are native to seawater and look a bit like snakes.
Conger eels look much more ferocious than eels, and their color is also darker than eels. They have strong teeth in both jaws, no scales, dark gray on the back, grayish white on the underside, and black edges on the dorsal and anal fins. Currently, the conger eels on the market are mainly wild, and even if they are farmed, most of them are temporarily raised after being caught. Because the cost of raising conger eels is very high, it is not cost-effective for farmers to raise them for a long time.
Conger eels are larger than eels. Eels are generally between 500 grams and 1,000 grams, while conger eels are generally more than 3 kilograms.