Small yellow croaker (Larimichthys polyactis) is also known as small yellow croaker, vertebrate, bony fish, and also known as "small fresh, big eye, flower color, cucumber, ancient fish, yellow scale fish, small spring color, golden dragon, thick scale fish, also known as" yellow croaker "and" small yellow flower ". It looks like a large yellow croaker, but its head is longer, its eyes are smaller, its scales are larger, its tail stalk is short and wide, and there are 5-6 rows of scales between the starting point of dorsal fin and the lateral line, which is golden yellow. 28 ~ 30 vertebrae. Otolith is bigger. The body length is about 20 cm, and the longest body length can reach 40cm. The back is grayish brown and the abdomen is golden yellow. It is a group of migratory fish in the offshore bottom, inhabiting the sea area with muddy or sediment substrate. The water depth of the spawning ground is10 ~ 25m in the coastal sea area, and the wintering ground is generally 40 ~ 80m. The fish school has obvious vertical movement, rising at dusk and descending at dawn, and inhabiting at or near the bottom in the daytime. Overwintering in the deep sea in winter, migrating to the coast in spring, spawning in March-June, mainly feeding on mysid shrimp, hairy shrimp and small fish, and returning to the deep sea in late autumn. The swim bladder can make a sound. China is produced in the East China Sea, the Yellow Sea and the Bohai Sea, and also distributed on the west coast of the Korean Peninsula. It is an important economic fish in China. For fresh food or made into salted and dried products; Swim bladder can be made into swim bladder glue; The testis can produce protamine.

Catfish, catfish. There are many species, such as catfish (native catfish), bearded catfish (pond catfish), leather bearded catfish (Egyptian bearded catfish), commonly known as slippery elder brother fish in Hakka.

Catfish, animal kingdom-Chordata phylum-Chordata subfamily-Actinidia-Siluriformes-Siluridae-Silurus-catfish species. There are ***4 beards on the mouth, which are long on the top and short on the bottom. They are carnivorous, mostly wild, and have low requirements for water quality. They can be cultured artificially. The growth rate is faster, and some varieties can grow to a large size.

Large-mouthed catfish, animal kingdom-Chordata-Chordata subfamily-Actinidia-Silurus-Siluridae-Silurus-Silurus species. Similar in appearance to catfish, it also has four whiskers, but its mouth is extremely large and its individual is much larger than catfish. It can be cultivated artificially, and the growth rate is fast. The fry propagated in that year can grow to 500-750g in the same year,1500-2000mg in the second year and 3000-4000mg in the third year. Most of the catfish sold in the market are this kind of catfish, which is relatively common in meat quality and cheap in price.

Bearded catfish, local bearded catfish, also known as pond fish and pond horn fish. Animal kingdom-Chordata-Chordata subfamily-Actinidia-Silurus-Silurus-Silurus-Silurus-Silurus-Silurus. 8 beards, 4 above and 4 below. Yellow body color, slow growth of wild fish, generally less than 1 kg, high nutritional value and good taste. It can be cultivated artificially and has great market potential.

Leather bearded catfish, also known as Egyptian bearded catfish and Egyptian pond fish, was introduced from Egypt. Animal kingdom-Chordata-Chordata subfamily-Actinidia-Siluriformes-Siluridae-Siluridae-Siluridae-Siluridae. Eight beards, black all over, huge individual. Most of them are cultivated artificially, and the growth rate is very fast, and they can weigh up to 2 kilograms a year, and the largest individual can reach more than 10 kilograms. It has low requirements for living water quality and is resistant to hypoxia. The meat quality is not very good and the market price is cheap. However, it is easy to breed, its growth rate is fast, and many people breed it.