Horseshoe Crab Finally Breaks His Silence!
Updated: Dec 1, 2020
True story. Well, almost.
Imagine you're a horseshoe crab. You live in the shallow and sandy area of the Delaware Bay. You're a healthy, happy male and one fine spring morning, in May, you decide it's time to fall in love - for a few moments at least, if not a lifetime - and so you set out to go ashore.
No one can tell you how to find the love of your life, but it is a gut call and you follow it. After all, you have a proud heritage. You (meaning, all horseshoe crabs) have survived 200+ million years unchanged. Some even say you've been around for more than 450 million years. Folks refer to you as the 'living fossil'. You accept the moniker.
It's midnight and full moon. Romance is in the air. As you prepare to begin your journey, an old horseshoe crab with a crazy look, sidles up to you. He looks worn out, but you pause to hear him. "Careful!" he whispers. "It's dangerous out there, especially on full moon nights."
"What?" you say, startled.
He scurries away before you can ask what he means.
You stare at him, then shrug. Then heave yourself out of the water and scramble up the wet sand. You look around, to make sure you are safe from predators when you realize you have competition. Not just one or two horseshoe crabs... but millions of horseshoe crabs are out there, each looking - like you - for an attractive female. "Dang!" you mutter. "Just my luck."
You move away from the teeming horseshoe crabs, weave your way through the millions of males and females, when suddenly, you find yourself lifted high into the air and thrown into the back of a truck. There is a roaring sound as the truck takes off. You find that you are not alone, but surrounded by hundreds of other horseshoe crabs, each looking terrified.
"What's going on?" you whisper. "Why have they captured us?"
No one can give an answer.
Two aliens transport you to a steel laboratory, where they scrub and clean you (especially the carapace on top of you) then fit you into a slot and stick a big stainless steel needle into you. They drain out your blue blood. Once they are done - they have half a jar full, at which point you're sort of feeling ill and faint - and they load you back into the trucks and go off on one more drive. When you come around, you find you are back in the same beach from where you had been picked up hours ago. Exhausted, traumatized... you slink back into the water.
What just happened to you, poor horseshoe crab?
Good question.
Each year, some 500,000 horseshoe crabs are picked up and bled for their blue blood. If you have ever taken taken a shot, if your parents or grandparents have had an implanted medical device, if you have ever been hooked up to an IV drip, you owe the horseshoe crab a debt of gratitude. You need to send a Thank You and a Get Well Soon card. Or send some money to the organizations that protect and preserve these species. I mean it. You and I and everyone who has ever been to a hospital for any kind of procedure, we owe these... ancient fossil-like organisms, with long tails and funny carapaces and countless eyes... our LIFE.
Seriously.
For if by some chance, all the horseshoe crabs in the world disappeared tomorrow, it would bring our medical industry (and our need for safe injectables and medical devices inserts) to a standstill. There is no other test in the world as sensitive as the one that we create from the horseshoe crab blood, not yet anyway (though scientists have been working on a substitute).
It so happens that horseshoe crab blood is extraordinarily sensitive to toxins from bacteria. In other words, it is so sensitive that it's the best test to measure if there is or isn't any bacterial contamination. The horseshoe blood not only forms a "gel" when it comes into contact with live bacteria, but also if the bacteria is dead. Not only does their blood detect traces of live bacteria, but also detects remnants of contamination even if the bacteria were actually dead.
Blue blood indeed.
The test we're talking about is called LAL, which means Limulus (the name of the the specific horseshoe crab that is found in the US Atlantic coas ) Amebocyte (the key cells in the crab's blood that is used) Lysate (the solution that is produced when the cells are destroyed).
How we arrived at the LAL test is another story and the focus of the next post.
TO BE CONTINUED.
Comments