One evening, we had a program on Horseshoe Crabs given by Jan Nichols. I learned TONS! I think we were all pretty surprised at the amount of knowledge that she rattled off in about an hours time. I'll list a few facts later. They following day at Assateague Island NS, I went to the visitor center at Tom's Cove where they had a touch tank! It looked sort of harmless and docile....
...so I picked it up, just like it was explained the night prior. Ewwww! What she did NOT explain is that it will wildly move both its abdomen section and tail WILDLY while wriggling its legs against the outside of the shell where you are holding onto it! I was sort of freaked out!
(Yes, I did squeal and yes I do believe the rangers snickered like I am sure they do ALL DAY LONG!
So, I turned it over and although it bent it abdomen back at a 90 degree angle along with its tail, I could hold it in such a manner that its legs weren't clacking against my fingertips (gross!) and could examine it more closely...
The little fart was still upset as you can see him contorting himself again as I put him back.
There there now.....
Horseshoe crabs are a member of the arthropod family (no wonder I freaked out) that have existed for about 350 million years with virtually no evolutionary changes. They exist only in temperate regions along only the east coast of continents (U.S. and Asia are prime habitats) on the continental shelf. They usually live for about 30 years, males reach sexual maturity at 3 years of age and stop physical growth, whereas females continue growing until their death and molt as needed and begin to breed at age 9-10 until their death. Males start to migrate to the barrier islands in February to await the return of the females when they arrive during the first full moon of May. Males latch on to the back of the shell of the female as she literally drags them around on her back, all season! By the end of the season, the female will have laid about 30,000 eggs in the wet sand with only 300 surviving to adulthood. The majority of the eggs and larva are gobbled up by shorebirds, turtles, crabs and fish. However, once its exoskeleton is formed and it has its tail (2 weeks after hatching) it has no natural predators, even during molts! As far as their diet, they are scavengers eating only a few times a year. Now, humans have used the molts for centuries as arrowheads and bowls. More recently watermen catch them and use the meat for bait for conch and eel. But, for the last few decades, a new use has cropped up...during the months of April to November, horseshoe crabs are harvested for medical purposes! They are taken to the lab, washed and a portion of their blood is collected then purified, and a certain protein is extracted and dessicated and put into vials to be reconstituted in a hospital or manufacturing setting. In the hospital if sepsis or other gram negative organism is suspected, a sample is mixed with the crab protein (Limulus Amebocyte Lysate endotoxin detection)...if it coagulates, the patient is suffering from some sort of gram negative infection and empiric treatment can begin sooner, while awaiting culture results in 24-48 hours, this test takes only minutes! And, in 1983 this protein became the ONLY method to test for gram negative contamination of injectable drugs (IV, vaccines, insulin), IV bags, and medical and dental devices or implants! WHO KNEW?! I certainly didn't learn of this in pharmacy school! And by the way....the crabs are NOT harmed, they are put back into the ocean, tagged, and not allowed to be "bled" again for a year. Now, 11 years ago, a synthetic protein was developed to do the same thing, but is still awaiting FDA approval. It is a time consuming process, each lab can only procure a few liters a day, (there are 5 labs) but each liter is worth $15,000! But, since I was pretty creeped out while holding the crab....I think I will stay in retail! I never counted on learning something related to my profession while on THIS vacation! But...was quite interesting! And by the way....a BIG THANK YOU to the horseshoe crabs for keeping our injectables entotoxin free and for helping with the speedy diagnosis of sick patients!
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