What is the difference between crabs and river crabs, and what is the difference between hairy crabs

Crab is a general term for crabs, and river crabs are a type of crab.

River crabs, also called crabs and hairy crabs, have a square shape and a hard texture of the cephalothorax formed by the combination of head and thorax. There is a pair of eyes on the front of the body and two pairs of sharp crab teeth on the sides. The pair of appendages at the very front of the crab is called the chelicerae, the surface is covered with hairs, and there are 4 pairs of feet behind the chelicerae, the sides are flattened and long, and the abdominal limbs have been degenerated.

The male and female of the river crab can be distinguished from its abdomen, which is round in the female and triangular in the male.

Lake crabs and river crabs are generally the same!

Do you know the difference between river crabs and crabs? Crab is a food that we all love to eat, and eating crabs will make people feel very happy, so do you know the difference between river crabs and crabs? Let's take a look at the difference between river crabs and crabs.

River crabs and crabs. Differences

1. The body shape and body structure are different, the river crab is a large crustacean, the body is divided into 21 segments, the back of the adult crab is inky, and the head and chest are 7cm long and wide on average. Crabs, on the other hand, are very small, but they have all the organs. After the hard shell of the crab is removed, the body of the crab is symmetrical and can be divided into frontal area, eye area, heart area, liver area, stomach area, intestinal area, and gill area.

3. The breeding method is different, the river crab floats in the shallow sea of the estuary for more than 35 days, and after 5 molts, it enters the larval stage of big-eyed. At this time, it also has a planktonic and benthic life, and can go up to lakes and marshes against the current. Bigeye larvae molt after 6 to 10 days to become juveniles and begin to live a benthic crawling life.

Crabs rely on female crabs to give birth to baby crabs, and each time the female crab lays a large number of eggs, the number of which can reach more than millions. After these eggs hatch in the belly of the mother crab, the larvae can break away from the mother and float around with the coastal currents. After several shells, they grow into big-eyed larvae, and the big-eyed larvae grow into juvenile crabs after several shells, and the appearance of juvenile crabs is almost the same as that of adult crabs, and then after several shells, they become crabs.

1. Although river crabs and sea crabs are both crabs, there are significant differences between the two, the most obvious being the difference in living environment. One lives in a freshwater river and the other in the ocean.

2. Then there is the difference in appearance. The size of the river crab is relatively small, and there are fine hairs on the crab claws and legs, and the species is single; On the other hand, sea crabs are relatively large, hairless, and have a variety of colors.

3. In terms of taste, river crab is better than sea crab, and the meat quality of river crab is relatively delicate and firm; The meat of sea crabs is looser, and the taste is not as good as that of river crabs.

4. From the point of view of purchasing, river crabs must be bought alive, and the dead ones are poisonous; And most of the sea crabs are frozen, because they die when they are caught.

5. In terms of nutrition, river crabs and sea crabs are comparable. At the same weight, the contents of vitamin A, vitamin B1, vitamin B2 and vitamin E were higher than those of sea crabs, while the contents of calcium, potassium and magnesium were lower than those of sea crabs. However, river crabs have much higher cholesterol levels than sea crabs.

How to distinguish between river crab and sea crab?

In terms of color, river crabs are generally blue-green, while sea crabs will be colorful.

In terms of body size, river crabs are generally smaller, while different species of sea crabs vary greatly in size, but they tend to be larger than river crabs.

In terms of claws, the first pair of chelicerae of river crabs will have fine hairs, so river crabs are also called Chinese mitten crabs, while the chelicerae of sea crabs are relatively rough but no hairs.

In terms of the shape of the back shell, the back shell of the river crab is square or oval, and the shape looks smooth, while the back shell of the sea crab is bright and diamond-shaped, with edges and corners.

The appearance is different: on the legs of river crabs, there are a lot of small hairs on the crab pincers, but there are no legs on the legs of sea crabs.

The taste is different: the meat of the river crab is very firm and delicate, and although the sea crab is large, the meat is relatively loose.

Different colors: There are many types of sea crabs, and the colors are also different, most of the river crabs are cyan, and there is no bright color.

One lives in freshwater and belongs to freshwater fish, and the other lives in saltwater and belongs to marine fish.