Top 10 Fun Facts About Crabs
Here are some fun facts about our favorite crustaceans, crabs! On a cliff note, when I was going into my research, I didn't expect to be flooded with mostly facts about crabmeat and killing crabs, but that's what I got. I don't know if that disqualifies this list for being a list of "fun facts" but we shall see, right?
The legs of the Japanese spider crab are the longest parts of their body, reaching roughly four meters, or about thirteen feet long. The shell, or carapace, of the Japanese spider crab can be a little more than fifteen inches or forty centimeters wide. The Japanese spider crab can also weigh up to around 41 pounds or 19 kilograms. Given their size, they are dangerous not just to hunt but to approach altogether. Despite the dangers, the Japanese spider crab is still considered a delicacy in Japan.
Fishermen harvest crab meat by removing one of a crab's claws. The crab is then kept in a water tank, where it will grow a new claw, as their claws are regenerative. The harvested claw can provide meat without killing the crab. It takes many claws to make a large meal, but those who do this are devoted to the practice. Depending on your perspective, this method may seem either merciful or cruel. Perhaps it can be both.
This is a good thing, considering how many things can harm them. But how is it possible for them to feel no pain? Their nervous systems are not complex enough to have pain receptors, unlike more evolved animals such as cats.
So, if you use crab claws for their meat, boil them, or accidentally run over them during migration, you can have a somewhat clear conscience if you are concerned about being humane. They might die or get eaten, but they feel no pain. This fact may comfort those who produce or consume crabmeat. However, it also means using the crabs' inability to feel pain to the cook's advantage. I'm not advocating for crab rights, but I can see both perspectives.
These migrations are similar to the monarch butterfly's migration. The number of crabs in these migrations can be very high, with hundreds of crabs attempting to reach the beach. Once the crabs release their larvae, they return to land in a "reverse" migration.
During these migrations, crabs are highly vulnerable to predators, especially humans. Coastal crabs are often crushed by cars driving over them. Despite the risks, the reward is baby crabs.
Before molting, crabs grow a layer of soft tissue under their old shells, which will become the new shell once the old one comes off. The crab then consumes a lot of water to weaken the old shell, allowing the new shell to eventually crack it open from the inside.
Generally, they establish a weak point, usually at the back of the shell, where the old shell breaks to reveal the new one.
The brown crab is the dominant species in the North Sea, the Atlantic Ocean, and the Mediterranean Sea. They live in waters up to about 330 feet deep. Brown crabs can grow to around nine inches wide and weigh about six or seven pounds.
Since the 19th century, brown crabs have been categorized as endangered due to overfishing. Laws have been implemented to protect them, such as prohibiting the keeping of brown crabs less than three inches wide to allow them time to reproduce. These regulations aim to prevent further endangerment of the species.
The lifespan of crabs varies significantly among species. For example, the giant Japanese spider crab can live as long as fifty or even one hundred years. In contrast, smaller species like hermit crabs usually live around three or four years, sometimes exceeding that by a year or two. Blue crabs can live up to about eight years or a decade. Horseshoe crabs can live up to twenty or even twenty-five years.
Since smaller species with shorter lifespans are more common, the average lifespan of a crab is often cited as three to five years. However, considering the longevity of some species, it is very possible that the average lifespan is actually around five to twelve years.
What's a decapod? An animal with ten legs. The prefix "deca" means ten, which is why a decade is ten years. This group of creatures includes crabs, lobsters, and shrimp. Though the shell or exoskeleton often blocks most of the legs from a bird's-eye view, the back four are usually visible. If you turn over a crab to inspect it, you will see all the limbs that are hidden by the shell, although some might be missing since crabs can regenerate limbs.
Okay, hear me out: not all crabs make good pets. You don't want to have a pet Japanese spider crab, given their size and potential to cause harm. However, mainstream hermit crabs and their subspecies, such as fiddler crabs and vampire crabs, make good pets. They are more impressive than your standard goldfish.
Most pet crabs are easy to care for and can withstand varied aquarium conditions. Depending on your preference, you can get a crab that lives for two years or one that can live for up to eight years. Pet crabs are a good option if you want a pet with longevity but are unsure if you can take care of a dog or cat. The only downside is that pet crabs are delicate and can be aggressive.
Despite having years of zoological knowledge, I initially assumed crabs were herbivores. In reality, crabs are omnivores. Their diet is predominantly seaweed, but they also eat meat when necessary.
Most crabs will eat worms, mollusks, fungus, or bacteria. Interestingly, crab larvae count as bacteria, so crabs can unknowingly be cannibals. Some crabs will even eat animal carcasses or garbage. Crabs with varied diets usually grow faster and larger than those that stick mainly to seaweed.
Feed them well, and they will grow.