There are stingrays, catfish, eels, eels, catfish and so on.

1, stingray

Stingray, also known as the devil fish, is in the Mesozoic Jurassic (about 180 million years ~ 140 million years ago) appeared in the sharks of the same kind, they have to hide in the sandy seabed habits. Stingray body flat, slightly rounded or diamond-shaped, cartilage without scales, pectoral fins developed, such as butterfly wings, tail whip-like, with poisonous spines. Living on the seabed. There are many species, the common ones are sharp-billed stingray, red ray, swallow ray and so on.

2, catfish

Catfish more mucus, body without scales. Dorsal fin is very small, no hard spines, with 4 to 6 fins. There are no blubber fins. The anal fin is very long and the posterior end is attached to the caudal fin. Catfish body color is usually dark brown or gray-black with slight dark cloudy patches.

3. Eel

The body is elongated, serpentine, gradually flattened laterally, and the tail is pointed and thin. The head is round, the muzzle is pointed at the end, the lips are quite developed, the lower lip is especially fat. The upper and lower jaws and the upper part of the palatine bone are finely toothed. Eyes small, covered by a thin wax. The two nostrils are far apart, the posterior nostril above the anterior margin of the eye, the anterior nostril in the muzzle. The right and left gill pores are united ventrally in a "V" shape. The body is not scaly. There are no pectoral or ventral fins, and the dorsal and anal fins are reduced to low skin folds without soft spines, all of which are united with the caudal fin. The body color is yellowish or orange-yellow, covered with black dots all over, and the abdomen is grayish.

4, eel

Eel, alias: white eel, white eel, river eel, eel, eel, green eel, wind buns, Japanese eel. Eel is a general term for species belonging to the classification of eel order. Also known as an eel, it is a fish with the appearance of a long snake, and has the basic characteristics of a fish. In addition, eels have migratory characteristics similar to salmon. Eel is a genus of fish, resembling a snake, but without scales, generally produced in the fresh and salt water interface sea.

5, Pelteobagrus fulvidraco

Pelteobagrus fulvidraco belongs to the class of spoke-finned fish, catfish order, family Fusidae, Pelteobagrus fulvidraco, commonly known as GaYaZi, HuangGuZi, HuangLaDing, yellow bone fish, etc., is the development of China's recent years, the rapid development of freshwater economic farming species. Whiskers 4 pairs; maxillary whiskers long, the end reaches or exceeds the base of the pectoral fin. The body is not scaly.

Baidu Encyclopedia - Scaleless Fish

Baidu Encyclopedia - Stingray

Baidu Encyclopedia - Catfish (Fish Name)

Baidu Encyclopedia - Eel (Traditional Chinese Medicine)

Baidu Encyclopedia - Eel (Eel Family Long-striped Serpentine Fish)

Baidu Encyclopedia - Pelteobagrus fulvidraco (Benthic Freshwater Fish)