The Indian Ocean region and Australia's Christmas Island are home to the world's largest terrestrial crab, which is highly skilled at climbing coconut trees to fetch coconuts.
They have always been brutal, but they are often preyed upon by humans, and now they are struggling on the tables of local residents, which is the coconut crab. But don't worry, they are not eaten most of the time now, but on the human table to find food.
coconut crab
Why is coconut crab now reduced to what it is? What does it mean for a large number of coconut crabs to go to the human table? What is the story of the coconut crab as the largest terrestrial crab? What other secrets are coconut crabs? Next, we will briefly talk about this big guy from the aspects of the coconut crab's living environment and its living habits, as well as their current state.
The big man in an arthropod
Coconut crabs are mainly distributed in the islands around the Indian Ocean, as well as on small islands near the Australian Sea, and the local environment is very suitable for the survival and reproduction of coconut crabs. Since they are the largest terrestrial crabs in the world, we can see how big they can grow.
Coconut crabs live in a place
Wild coconut crabs can grow up to 4 kilograms after many molting developments, and if given longer time, coconut crabs can grow larger and heavier, reaching a width of up to 1 meter.
In the large family of arthropods, although spider crabs have the largest size of crabs, they are a little far from the weight of coconut crabs. It is no exaggeration to say that a coconut crab can grow up to 10 kilograms, which is larger than a garbage can. However, the coconut crab does not live like other crabs, and it is strictly a type of hermit crab.
Crabs larger than a garbage can
Past studies have shown that coconut crabs are the only subspecies of the hermit crab family and are closely related to other hermit crabs. At the same time, coconut crabs also have a strong ability to survive on land and can live in the land environment for a long time. However, this ability must wait until they have matured before they can go to sea.
Coconut crabs only live in the sea before they mature, and adult coconut crabs drown once they are in the water for more than 1 hour. This is due to the fact that their respiratory organs are not the same as those of other animals, and they have evolved gill lungs somewhere between gills and lungs.
"I'm a terrestrial animal"
This tissue allows them to absorb oxygen from the air, but it cannot isolate the oxygen in the water. At the same time, the development of the gill lung will expand laterally and turn outward, in order to increase the surface area and strengthen the respiratory effect.
The gills are at their cephalothorax, where blood pressure is relatively low and facilitates the diffusion of gases mixed into the bloodstream and finally back into the pericardium. Although coconut crabs cannot live in water for long periods of time, the respiratory system still needs a certain amount of moisture to work well. They use their last pair of tail feet to soak water in their gills, and they use their sponge tissue to transfer water from the puddle to their jaws to drink.
Humans are testing the gills of coconut crabs
Since it is a hermit crab, it is naturally inseparable from the sojourn life. When they are still in their infancy, coconut crabs, like other hermit crabs, will look for carapaces that can live in, and objects such as coconut shells will be used as writers by them. However, after maturity, coconut crabs will no longer live as a hermit, and their soft abdomen will begin to keratinize and there will be a few cinnamon deposits. This hardening process frees them from parasitic life and helps them survive better on land.
Unripe coconut crabs look for hermit carapace
Most of the time we learn that the coconut crab is a vegetarian animal, and the delicious coconut is their best food. But in fact, they are an omnivore, and in addition to coconuts, they also prey on small animals and insects, including some birds, which they also eat. Non-picky eaters will even eat some rotting animal carcasses, or even human garbage.
Coconut crabs' anchovies are their offensive weapons, but don't underestimate them, which are much more powerful than other crabs. I believe that many people have been caught by crabs, but it is not fun to be caught by coconut crabs, because their feet can produce a maximum of 336 kilograms of pressure, imagine what it is like to be bitten by a lion.
Small crabs can catch blood, let alone coconut crabs
Adult coconut crabs have a hard shell and strong pliers that make them almost free of predators. As an opportunistic predator, any prey that enters its prey range will have a hard time escaping the giant claws of the coconut crab. Coconuts are only their secondary food, which is much more convenient than spending a day on coconuts, eating some garbage or preying on small animals.
Although coconut crabs are very powerful, it is still very difficult for them to open a coconut, not so much to open the coconut, but to peel off the shell of the coconut layer by layer. Unless there is nothing to eat, the coconut crab will eat coconuts or some fruit seeds.
Coconuts are not easy to open
It is such a big man who runs rampant on the island, but now it is suffering from an existential crisis, after all, the coconut crab is no strong enough to fight people.
Another species that can only be eaten and protected
I don't know what the world's first crab eaters really thought, but perhaps because of the courage to try, crabs have become one of the human recipes, and coconut crabs are no exception. Don't look at the coconut crabs that look weird and look like oversized spiders, but according to the descriptions of the locals, coconut crabs are actually a very delicious food.
Coconut crab delicacies
Coconut crabs that have long lived on the island to eat coconuts have a rich coconut aroma after cooking, and their large size means that there is flesh under the carapace. In the past hundred years or so, coconut crabs have been hunted in large numbers.
Can't escape the fate of being eaten
According to local residents, catching coconut crabs is as simple as a little food to trap them. Coconut crabs have a very developed sense of smell, and their antennae form are shorter and more insect-like, and can determine the density and direction of odor. And they can also judge whether they are hydrophilic or hydrophobic according to the water molecules they smell, and the overall taste process is very meticulous.
Because the olfactory system in their brains develops more strongly than other crabs, this allows them to distinguish the aromas of fruits such as rotting and coconut, even if they are hundreds of meters apart. Therefore, to catch them, all you need to do is to spread coconut leaves in the hole where the coconut crabs live or where they frequently haunt, sprinkle some carrion and fruit until they appear.
Coconut leaf
The large-scale human catch is a disaster for coconut crabs because their reproduction is not as fast and efficient as other crabs. Coconut crabs only breed in the summer, and after mating on land, the female sticks the eggs under the abdomen, and when it is close to hatching, the female crabs migrate to the sea to lay eggs.
Spawning can be the most dangerous thing for coconut crabs because they can't swim and can't stay in the water for long periods of time. If they are swept away by the waves when they spawn, they will only drown, and the thick body of the coconut crab will not be able to support them in the water.
The sea is fatal to adult coconut crabs
Coconut crabs hatched in the water are also swallowed by many predators, and their numbers are gradually reduced from the beginning. It wasn't until months later that they were able to come ashore. After landing, the coconut crab begins to harden and then reaches sexual maturity after another 5 years of growth. The long growth cycle of coconut crabs puts them in a disadvantageous situation when faced with hunting, and it takes about 40 years or even longer for them to become complete.
Coconut crab populations began to decline significantly in the 1980s, and human activities have rapidly reduced their habitat, and coconut crabs in many areas are already on the verge of extinction. However, after several modifications and biological determinations, the wild coconut crab population was judged "fragile" in 2018.
I'm vulnerable
But now we can still see videos and reports of eating coconut crabs, so can coconut crabs be eaten in the future?
Artificial breeding may be the way out
Wild coconut crabs also proved to be less suitable for consumption because of their complex feeding habits and the easy accumulation of toxins inside the body. For example, coconut crabs that eat sea mangoes accumulate a cardorolactone cardolactone, which causes the heart to beat too fast and ventricular fibrillation to induce cardiac shock.
Sea mango
In the past, they often appeared on human tables, but now they appear most of the time at the tables of local residents, not to be eaten, but to find food. Due to their well-developed sense of smell and nocturnality, local residents attract a large number of coconut crabs to feed every time they barbecue or do activities in the wild.
BBQ
Many areas where coconut crabs live have passed legislation prohibiting the capture of spawning females, as well as minimum legal size catch restrictions to maximize the survival of coconut crabs. This also makes many residents can only watch them take food, and occasionally they will catch a few to eat.
In short, the coconut crab is repeatedly struggling on the human table, the delicious coconut crab for the local residents, eating is not right, not eating is not, coconut crab "robber crab" nickname is once again taken to fruition.
Robber crab
Considering that this crab still has a large potential market, it is not that there is no artificial breeding of coconut crabs, but their slow growth cycle makes it difficult for coconut crabs to bring as much profit in terms of profit as other aquatic products. Perhaps for foodies like humans, artificial breeding of coconut crabs is the best way to protect them.