The Fascinating World of Crabs

 The Fascinating World of Crabs: Blue Blood, Sideways Walks, and More!

Crabs are one of the most enthralling beings on the planet, crawling sideways along beaches, running away to hide in tide pools, and finally, being the starring attraction in some seafood feast. Yet there seems to be so much more to these armored critters than meets the eye. Did you know they have blue blood? Or that some can climb trees? Well, let us dive into the amazing world of crabs.  

 1. Crabs Literally Have Royal Blue Blood

Unlike iron-carrying red blood among humans, crabs (and other arthropods like horseshoe crabs) possess blue blood! This quality is because their blood contains hemocyanin, a copper-based protein that turns blue when oxygenated. Scientists actually use crab blood in medical research to detect harmful bacteria in vaccines and medical equipment—talk about a life-saving crustacean!

2. They Can Walk Sideways… But Not All of Them! 

Most crabs scuttle sideways because their legs bend that way, making it the fastest escape route from predators. But some, like the frog crab and spider crab, can walk forward just fine. The ghost crab is even speedier-it can run up to 10 mph (that's faster than most humans jog😉)! 

3. Some Crabs Are Tree-Climbing Ninjas 

Meet the coconut crab-the world's largest land crab, weighing up to 9 lbs and stretching 3 feet wide! These giants can climb trees to snag coconuts, which they crack open with their powerful claws. They have even been known to steal shiny objects like silverware😳 (tiny pirate crabs, anyone?).

4. What's the difference between shedding shells and changing clothes? 

You see crabs are not as humans grow, they molt, splitting a hard shell and wriggling out of it. This new shell is soft and has to harden before risking being eaten alive, so to protect themselves, some crabs eat their old shell for calcium. 

5. Not All Crabs Live in the Ocean 

It is more common to visualize crabs at beaches, but they are also found in freshwater rivers, deep-sea vents, and even deserts! The Sally Lightfoot crabs scamper over the lava rocks within the Galápagos Islands, and the purple land crab is buried in tropical forests.

6. They Communicate with Bubble and Claw

But crabs don't have vocal cords, rather they drum their claws, wave their pincers, and even produce sounds like bubbles to communicate. Like all fiddler crabs... One claw is enlarged to assist in fighting and flirting-the males waving it aloft in semaphore to attract females. 

7. A Crab's Eyes Are on Stalks and They See Far More Than Us 

Have you ever seen how crab eyes pop out like periscope at time? Also with this type of vision, crabs are able to get everything in their environment by sight so they can easily identify possible predators attacking them. Some of them also see ultraviolet light, which none can possibly imagine how crabs use it to find food and mate.

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Bonus: Immortal Crabs?  

Though no crab lives for eternity, the horseshoe crab (not truly a crab) has roamed through 450 million years- larger than the dinosaurs! Its blue blood that is used in medicine today comes from these ancient creatures. 

Final Thought: Crabs Are Underwater Superheroes! 

From their blue blood saving lives to their tree-climbing antics, crabs are way more than just beachside critters or dinner. 

Fun Fact : If you ever see a crab waving its claws wildly, it might be saying, "Back off!" or "Hey, good-looking!"—crabs have a whole language of claw gestures. 🦀💙