Photography And Half-Thoughts By Mitchell Hegman

...because some of it is pretty and some of it is not.

Thursday, April 13, 2017

The Blood of Horseshoe Crabs

Horseshoe crab blood is worth something.  It’s worth quite a lot, actually.  A quart of horseshoe crab blood has an estimated value of something near $15,000.
If you don’t know much about horseshoe crabs, know this: the horseshoe crab you find today is pretty much the same as the one you would find as a fossil from 450 million years ago.  They have not changed much.  They didn’t need any kind of change to survive.
They have good blood.
The blood of a horseshoe crab is bright blue in color.  The color is a reflection of the fact that oxygen is carried using copper-based hemocyanin.  Our red blood uses iron in hemoglobin for the same.
But the real trick is what horseshoe crab blood does when confronted by bacteria.  Where our blood might require a couple days for white blood cells to muster a defense against the bacterial invaders, the defensive amebocytes in horseshoe crab blood may successfully react in as little as 45 minutes.
Over recent years, biomedical researchers have been doing a great deal of life-saving work with horseshoe crab blood.  Some concern exists about horseshoe crab populations.  At one time the crabs were over-harvested and destroyed to make fertilizer.  In some areas, the crabs are still harvested and used as bait.  The horseshoe crabs used in the biomedical industry are captured, bled, and released into the wild again. Still, some question remains about the survival rate of the crabs released into the wild again.
The video posted below explains the blood harvesting process.
 --Mitchell Hegman
Here is a link to the video posted:


  1. Thanks for the info. I hope the crabs don't follow the path of other creatures and become extinct because of over exploitation.

  2. There seems genuine concern for them.