Original Liu Yadan
Autumn, chrysanthemum crab fat, is a good time to taste crabs. However, some people's understanding of crabs still stays on the hairy crabs that can be eaten.
After the delicious and dense taste of crab paste, let's walk into more crabs. Learn about several adorable ornamental crabs today.
Author | Liu Yadan
【Deputy Secretary-General of China Association for International Agricultural Exchanges, National Chief Science Communication Expert】
Review expert | Liang You
【Fish Room, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences】
Crabs are delicious and fun invertebrate aquatic animals, there is a myth: slate to slate, a pair of eyes under the slate, eight awls and two scissors, saying that it is a cute crab. There is a huge family of crabs in the world of aquatic organisms, according to the Popular Science Encyclopedia of China, there are about 4500 species of crabs in the world, and there are nearly 800 species in China. Crabs are so big, of course, they can't be introduced one by one, only pick up elegant customs to enjoy and share.
The taxonomist Shang Wu interpreted the 6 categories into 6 factions, namely:
Dromiacea,
Archaeobrachyura,
Oxystomata,
Oxyrhyncha,
Cancridea,
Brachyrhyncha
If it is simply classified, according to the crab growth environment, it can be divided into sea crabs, river crabs, lake crabs and stream crabs, etc.; according to the use, there are common edible crabs, ornamental crabs, and many undeveloped crabs, which are thousands of miles of "crabs", all over the world, self-enjoyment, self-destruction, and are part of the biodiversity of the colorful world.
Most crabs live on the sea, with the most abundant crabs in shallow tropical seas, such as frog crab family, steamed crab family, jade crab family, pike crab family, fan crab family, which mainly live in the coastal area; The family Cymbidium and the family Sand Crab live in the vast intertidal zone. Some are rarer, such as drifting crabs and bow-legged crabs, which can attach to wood or other floating objects to live.
There are also many crabs that live in symbiosis with other animals, such as the cotton crab family and the Guan Gong crab family. More interestingly, many crabs, such as bean crabs, often burrow into the coat cavities of some mollusks, or in the tubing of hairy species. There are also crabs such as the family Saccharinidae, which live in sacs formed by reef-building corals, and female crabs are confined to the sacs for life after mating, and the hatched larvae can escape through unclosed small holes.
In addition to these marine crabs, some crabs live in semi-salty water, that is, where the sea meets rivers, such as saw-edged blue crabs, and some crabs grow and multiply entirely in fresh water, growing in lakes, rivers or mountain streams.
Having said so much, perhaps we can be fair to crabs: they are not only the domineering side. Many crabs are beautiful in appearance, easy to raise, and suitable for viewing in aquariums.
Many ornamental crabs are stream crabs, which are highly ornamental and can also be artificially bred. In particular, the feeding habits of the creek crab are very mixed, basically eat everything, and it is better to breed indoors. Here, I would like to introduce two strange crabs – the tidal crab and the hermit crab.
Brook Crab Image Source/Network
Tidal crabs
The biggest feature of the tide crab is a pair of claws of great disparity in size, and the large claws placed on the front chest resemble the shields of samurai. The tide crab will make the action of dancing large claws, so it is called "tide crab". The purpose of this "tide-raising" action is not only to intimidate the enemy with a large claw, but also to show his majesty to his spouse. The big one is called the mating claw, which is brightly colored, has a special pattern, and weighs almost half the body. Curiously, if the male unfortunately loses the large claw, a small claw will grow in place, and the original small claw will grow into a large claw instead, performing the same function.
The big claw of the tidal crab Courtesy of The photo/Zhuang Ping
In addition, the tide crab has a pair of matchstick-like protruding eyes, and when foraging, both eyes stand high to observe the surrounding movements. Evacuate quickly as soon as the situation is discovered. The crabs are beautiful in color, including coral red, bright green, golden yellow and light blue.
Tide-catching crabs inhabit the intertidal zone of the beach, on the beaches on the edge of the Mauritanian desert in Africa, there are many such tide-catching crabs, and China's coastal mangrove wetlands and the yangtze River are also typical habitats for tide-attracting crabs. I traveled to Africa many times in the late 1990s, and I also saw tidal crabs on the beaches, holding large claws, and the spectacular scene was like a thousand horses standing tall and saluting us.
Now that the tide crabs have also been included in the list of ornamental crabs, it is believed that they are not only attracting tides, but also attracting wealth. However, raising tidal crabs at home also needs to arrange special anti-escape devices to prevent them from running around at home.
Tidal crabs on the arc of the Yangtze River near the shore Courtesy photo/Zhuang Ping
hermit crab
The hermit crab mainly uses the shell of the snail as the host, and the maximum diameter of the hermit snail can reach 15 cm. Because of its fierceness, it is often used to eat the flesh of mollusks such as shellfish, occupy its shell for its own, and never "pay rent", so the hermit crab is also known as "white housing" and "dry house". As they grow older, the hermit crabs change their shells to live.
The year before, I went to the Toronto Aquarium in Canada and found many hermit crabs in the water tank, and the commentary board read: "Hermit crabs look for empty shells to shelter themselves, and when they grow up, they will look for larger shells to relocate to a new home." For this reason, picking up shells on the beach is never a good idea. ”
Photo courtesy of Liu Yadan
There are many types of hermit crabs, there are hermit crabs, quasi-hermit crabs, stone crabs, etc., common large hermit crabs, also known as square wrist hermit crabs, it is very large, the length of the large claws is more than 10 cm, the surface and edge of the two claws have many thorny protrusions, and there are spines on the steps. China's wild hermit crabs are mostly produced on the coast of the Yellow Sea and the southern seas, and are easy to find in the rock crevices of the beach and the sea. They are also sometimes hidden in places such as bamboo knots, spikes of coconut shells, corals, and sponges. Hermit crabs are omnivorous and are also known as "scavengers".
Hermit Crab Image Source/Network
At present, people invite hermit crabs into their homes, not only because these hermit crabs themselves are ornamental, but also because the "houses" they live in are very beautiful. Therefore, some people artificially provide beautiful shells for domesticated hermit crabs. In the water tank, the stillness of the shell sets off the movement of the crab, which is also a scenery.
In addition to the tide crab and hermit crab, there are also many cute ornamental crabs, such as rainbow crab, purple ground crab, leopard point crab and so on. It's funny just to hear the names, and we'll get to know them together.
Rainbow crab
Rainbow crab, scientific name is armed cylindrical crab, native to West Africa, is a member of the family Crab family. Wild rainbow crabs are found off the coast of West Africa and also in some inland deltas, such as the Volta Delta and Cape Verde.
Many crabs are amphibians, such as rainbow crabs, that is, adult and juvenile crabs live most of the time on land, and female crabs must return to the sea to release their eggs during the breeding period. The fertilized egg hatches tiny larvae that develop into juvenile crabs. If the juvenile crabs do not come ashore in time after their development is complete, they will drown. Adult crabs can completely enter the whole water environment on the water side for a long time.
The scientific name of the rainbow crab is called armed round axis crab, that is, its size is larger, more aggressive, in the wild they are a typical of large deception, will eat smaller crabs, small reptiles, amphibians, molluscs, fish, insects, etc., but also eat vegetarian, most of the fruits, vegetables, rhizomes, etc. can eat, eat more mixed.
Rainbow Crab Image source/network
This crab has a strong sense of territory, it is easy to kill each other, it is best to raise it alone, or it will soon lack arms and legs, the appropriate temperature is 18 ° C -30 ° C, but it is not yet artificially reproducible. Rainbow crabs look like their names, and indeed they are as colorful as a rainbow after the rain.
Purple ground crab
The purple earth crab is a genus of ground crabs in the family Earth Crab family, and is said to be a close relative of the Christmas Island red crab, and both are brightly colored crabs. It is distributed in the Philippines, Indonesia, the Indian Ocean islands, Taiwan Island and the Paracel Islands in Chinese mainland, living in seawater, generally inhabiting moist crevices on land, and often migrating to the sea to lay eggs during the breeding period. Ornamental purple ground crabs can eat fruits, vegetables and fish and shrimp, but they cannot be farmed artificially. There is also a simple way to identify purple ground crabs: elegant UV coat + red gloves.
Purple Ground Crab Image Source/Network
Leopard dot crab
The leopard spot crab, also known as the Sulawesian leopard point crab, is found in the freshwater lakes of the Indonesian islands. Leopard point crab territorial awareness is relatively strong, it needs to find a number of hiding places for itself, the big leopard point crab is overbearing, how much indoors will hurt the grass and shrimp in the tank, the water in the tank is deeper, and it can also be mixed with pelagic fish or larger fish. Leopard point crab is famous for its whole body leopard point, although it can eat anything, but overall it still likes to eat meat as much as the leopard.
Leopard Spot Crab Image source/network
Mentioned in the text
Many crabs live in the intertidal zone
In fact, the intertidal zone is the window for human beings to understand the ocean
It is also the most convenient sea area for obtaining seafood
A lot of the seafood on the table comes from the intertidal zone
The mangroves on the intertidal zone are deep and muddy
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