On the autumn table, the plump crabs, flowing oily yellow, make people salivate when they look at it. A plate of crab is often enough to become a top table dish, adding infinite flavor to the feast. But have you ever thought that crabs have evolved their most delicious meat in order to avoid being eaten by humans? Crabs, as a member of nature, are not only a miracle of biology, but also the intersection of human civilization and natural ecology.
The evolution of the crab: from lobster to hexagonal warrior
Crabs come in a variety of forms, but their early appearance was similar to that of lobsters. According to scientists, dating back hundreds of millions of years, the ancestors of crabs appeared in the early Jurassic, contemporaneous with the dinosaurs or even earlier. At that time, their appearance may have been closer to that of modern sea creatures, with slender bodies, well-developed tails, and rapid movements. It resembles a modern lobster, rather than the flat, stiff body we know today.
Over time, the crab gradually abandoned its slender tail and evolved into its current hard shell and flat body. This evolutionary process, which took a full 50 million years, is an innovative journey in the evolutionary history of crabs, also known as "crabization". Crabs are constantly adapting to changes in the marine and terrestrial environment in order to survive and thrive.
In the race for survival, the crab gradually evolved a hard shell and powerful pincers, becoming one of the top predators among marine life. Their movement has also become unique, with eight thin legs and extremely fast speeds, allowing them to hunt prey in the underwater world with ease.
Through the change in appearance, we can clearly see the process of crabbing, just like a heavy truck loses the trunk of the cargo, leaving only the hard front of the car, and becomes a tank with strong defense.
First of all, the body of the crab gradually flattens and stretches horizontally, and even edges and corners appear at the edges, which makes their appearance more compact and strong. The cephalothorax was joined together to form a single carapace, which enhanced the overall protective capability. The abdomen has also undergone a dramatic change, atrophiing and folding into the lower part of the cephalothorax to be wrapped around the carapace, and the original protruding part gradually disappears, making the whole body more solid. The tail fan also disappeared completely, and was transformed into a sixth appendage, which enhanced the crab's movement and flexibility. At the same time, the abdominal muscles and nerves degenerate and fuse, making the crab's body more efficient and unified.
These changes not only make the crab's appearance more adaptable to the environment, but also provide it with a stronger ability to survive. In nature, the lower body of crabs is the object of animal hunting, and in order to survive and develop, they have to endure the pain and love, and evolved into the current form. This process took tens of millions of years, but in the end, the crab became an important force in the ecosystem, demonstrating the infinite wisdom of the evolution of life.
The survivability and characteristics of the crab: the power of the hexagonal warrior
First of all, crabs live in a very wide range of environments. They mainly inhabit the oceans, especially in the shallow tropical areas, and have a wide variety of species. In addition, some crabs have adapted to freshwater environments, and even a few are able to survive in land mud burrows. There are about 4,700 species of crabs in the world, and about 800 species in the mainland alone, demonstrating the diversity and adaptability of the species.
The reason why crabs are able to survive and reproduce in various environments is inseparable from their strong ability to survive and adapt. They have a hard shell and excellent defenses against attacks from predators.
In addition, the crab has a strong attack power, and its two large pincers have an extremely strong grip force, which is enough to catch prey or defend against foreign enemies. The speed of the crabs is also not to be underestimated, and when they run, they are able to reach an astonishing 18 kilometers per hour, making them agile and difficult to catch. At the same time, crabs also have excellent survival intelligence, and can flexibly use their surroundings to protect themselves, such as squeezing their flat bodies into the cracks of stones to avoid danger.
Amazing respawn abilities
Crabs are known in nature for their superior defense, attack, survivability, speed and agility, and can be called the "hexagonal warrior" of nature. These traits make crabs occupy an important place in the ecosystem, while also being relatively less threatened by natural predators.
At the same time, the crab has an amazing ability to regenerate, which is also a reflection of its survivability. Although their body shells are hard and protect their soft internal tissues, crabs' claws are relatively fragile and can be easily caught and broken by predators. When faced with difficult situations, crabs will adopt an amazing strategy of abandoning a part of their body in order to attract the attention of their enemies and give themselves a chance to escape. So even if your crab's claws or pincers are damaged, you don't have to worry too much because they have the magic of regrowth. The newly grown pincers may be smaller, or even inconsistent in size, but this does not affect the crab's ability to survive and hunt, but shows its indomitable vitality.
Fiddler crabs with an imbalance on the left and right
Fiddler crabs are a special type of presence among crabs, and they are known for their large and disparate pincers. One of the male crab's pincers is particularly large, taking up almost half of the body, while the other is relatively small and is dedicated to eating. This particular appearance feature is mainly used to attract subjects and is one of their unique breeding strategies.
Although crabs have a hard shell to protect themselves, this also becomes one of their weak points. Since the shell hardens as the body grows, crabs need to molt to renew their shells every time they grow. During the molting period, crabs become very fragile and have no shell protection, making them easy prey for predators.
The mating process of crabs is also closely related to molting. Mating can only take place if the female crab becomes a soft shell after molting. At this time, the male crab will be attracted by the ecdysin information released by the female crab and come to protect the female crab and mate. Male crabs need to make sure that the female crab is safe during the soft shell period in order to pass on the genes.
Female crabs usually lay millions of eggs and hold them in their bellies to hatch. After hatching, the eggs will drift to various places with the current, and they need to rely on their luck and ability to grow smoothly. These baby crabs undergo several molts and gradually grow into larvae, and then several molts before becoming adult crabs.
Crabs are omnivorous animals, and they come from a wide range of food sources, including plankton, mollusks, crustaceans, fungi, and even decaying organic detritus. This wide range of dietary habits allows crabs to play an important role in the ecosystem and maintain a stable ecological balance.
The unique species and ecological role of crabs: diversity in ecosystems
In addition to the common crabs, there are many unique crab species that play different roles in the ecosystem.
For example, the coconut crab, which is one of the largest hermit crab species among terrestrial crabs. Coconut crabs excel at climbing straight coconut trees and peeling hard coconut shells with their large, strong pincers, hence its name. They are huge, can grow up to 1 meter long, and have colorful patterns on their bodies, and their two large claws look very aggressive.
The spider crab is one of the largest crustaceans in existence, known for its large size and long legs. Spider crabs have a bright orange appearance and long, thin legs. They live in the deep sea, are huge, and are a symbol of superiority. However, despite their large size, spider crabs themselves are relatively cute and easy targets. In nature, spider crabs can live for hundreds of years and have a fairly long lifespan.
Then there's the boxing crab, a tiny crab that lives near coral reefs. Their peculiarity lies in the fact that they use poisonous anemones as weapons, and they are able to strike hard like boxers when they encounter danger. Sea anemones are also able to use the swimming movements of boxing crabs to find more food and achieve a mutually beneficial symbiosis.
These bizarre species of crabs showcase the wonders of nature and are breathtaking. Although they have evolved as much as possible to look inedible, humans have developed various cooking modes that demonstrate the spirit of human exploration of cuisine.