What Kind of Fish Is Ding Fish? A Detailed Explanation of the Differences from Sardines

In everyday life, we occasionally hear the term ding fish, so what kind of fish is ding fish? Is it the same as sardines? Are there any differences between the two? In fact, ding fish is not a formal name, but another name for the mullet.

Mullet is a fish of the order Mugiliformes, family Mugilidae, genus Mugil. The body is elongated, nearly cylindrical in the front and laterally compressed in the rear, generally 20 to 40 cm in body length and 500 to 1,500 g in weight; the whole body is covered in cycloid scales, with large eyes and well-developed eyelids; the teeth are small and villiform, growing along the edges of the upper and lower jaws; there are two dorsal fins, the anal fin has 8 fin rays, and the caudal fin is deeply forked; the body, back, and head are bluish gray, and the belly is white.

Mullet is a eurythermal, euryhaline fish that can live in freshwater, brackish water, and saltwater. It prefers to inhabit coastal nearshore waters, bays, and river estuaries. It is one of the most important economic fish species in brackish-water aquaculture along the southern coast of China, and also one of the most widely distributed important economic fish species in the world.

Sardines, by contrast, are a collective term for fish of the class Osteichthyes, order Clupeiformes, family Clupeidae, genera Sardina, Sardinella, and Sardinops, as well as certain edible fish of the family Clupeidae. It also refers to the common herring processed into canned fish in oil, as well as other small herrings or herring-like fish. Sardines are slender, silvery small fish, with a short dorsal fin and only one dorsal fin, no lateral line, and a scaleless head. The body length is about 15 to 30 cm (6 to 12 in); they live in dense schools, migrate along the coast, and feed on large amounts of plankton; they mainly spawn in spring, and the eggs and the larvae that hatch a few days later drift with the water until they metamorphose into free-swimming fish.

Sardines are neritic warm-water fish, distributed in isothermal marine zones between 6 and 20 degrees north and south latitude, and are generally not found in the open sea or the ocean. Sardines are mainly used as food, but the fish meat can also be made into animal feed. The uses of sardine oil include the manufacture of paint, pigments, and linoleum, and in Europe it is also used to make margarine. At the same time, it is an important marine economic fish species in the world.

It can thus be seen that mullet and sardine are two completely different kinds of fish, and the two have obvious differences in species, appearance, distribution range, living habits, and so on.

Tips for Selecting Mullet

1. Fish gills 

Fresh fish have tightly closed gill covers, and the gills are bright red, sometimes still carrying blood, with no mucus or dirt and no off odor. If the gills are pale red or grayish red, the fish is no longer fresh. If the gills are grayish white or blackened, covered with thick mucus and grime, and have a foul odor, it means the fish has already spoiled and deteriorated.

2. Fish eyes  

Fresh fish eyes are smooth and bright, slightly convex, and perfectly uncovered. Stale fish eyes are dull and lusterless, and may even be covered with a thick pasty film or dirt, making the eyeball unclear and sunken. In spoiled and deteriorated fish, the eyeball ruptures and shifts position. 

3. Fish fins  

On fresh fish, the skin of the fins clings tightly to the fin rays, intact and glossy in color. On stale fish, the skin of the fins has faded in color and shows cracking. In spoiled and deteriorated fish, the skin peels off and the fin rays separate.

4. Skin 

Fresh fish skin is glossy, with intact scales that cling tightly to the body, and the scale layers are distinct. The thin mucus attached to the fish body is an inherent physiological phenomenon of the fish. Stale fish skin is dull and lusterless, the scales are loose and falling off, the layers are blurred, some fish scales have changed color, and the skin has thick mucus. In spoiled and deteriorated fish, the color has completely changed, the skin has thick mucus. In spoiled and deteriorated fish, the color has completely changed, the liquid on the skin is sticky to the touch, and there is a foul odor. 

5. Flesh  

Fresh fish flesh is tightly organized and firm, with obvious elasticity when pressed by hand. After the hand is released, the depression at the pressed spot is slow to recover for a long time, and the hand can make the flesh separate from the bones.  

6. Body posture  

Fresh fish feel firm and straight when picked up. Some fish, such as yellow croaker or perch, mullet, and so on, are placed in ice when marketed to keep them fresh, with the head and tail turned upward, and they are still fresh. If, when held in the hand, the flesh has no elasticity and the head and tail are soft and drooping, then it is not fresh enough. Fresh fish have firm lips that do not change color, a tight belly, and a round pit shape around the anus. Stale fish have pale lip flesh that may even separate and split from the bone, a swollen and soft belly, and a protruding anus.

Tips for Selecting Sardines

When choosing fish, check whether the flesh is elastic. Buy fish with gills that are pale red or dark red, and eyes that are slightly convex with clear black and white; buy fish with an intact appearance and no fallen scales; buy fish with no foul fishy smell. These are fresh.  

Sardines themselves need to meet some important conditions: first, the sardines must be fresh enough and cannot be frozen; even if just caught and brought aboard the boat, they must be kept fresh in ice water at around zero degrees; second, they must be handmade within 1 to 2 days; third, they must be marinated in high-quality olive oil.

Sardines with black eyes and a silvery sheen on the skin are best. Fish freshness can be identified from the following aspects:  

1. A fresh fish will certainly have clear, bright, full, and spirited eyes, with eyeballs that protrude and a clearly defined black-and-white boundary. If the fish eyeballs are sunken and the color is cloudy, it is better to give them up.  

2. A slightly closed but easily opened fish mouth presents a kind of peaceful calm, and the scales on the body are like a carefully worn formal dress, neat and close-fitting, with no sloppy shedding. Even if you open the tightly closed gill cover, what you see is fresh red, clearly defined gill filaments. Fish with loose scales that fall off easily and slack gills cannot bring you a delicious enjoyment.  

3. Transparent, smooth mucus covers its whole body. Although it has a fishy smell of its own, the odor is not strong, and there will be no foul fishy smell that disgusts you. These fresh characteristics mostly apply even to frozen fish, and fresh frozen fish have bright flesh cross-sections, and after thawing, the weight will not change much from before.