Crash: A Tale of Two Species
Video: Blue Blood at $15,000 a Quart

The horseshoe crab’s unique blood has powerful properties valued by the biomedical industry.

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  • Chadd Long

    How much blood does one crab hold?

  • jonita

    I need to know how much blood i will need

  • Angela G Christopherson

    Does the crab die after milking the blood or are they preserved?

  • Dave

    Angela, take another look at the video. They said most survive and are returned their environment where they are captured again at a future time.

  • Rictronics

    Estos animalitos vuelven a su habitat? Como producen tanta sangre azul? Son criados especialmente para este propósito?

  • Fajar

    Incredible story, magnificent creature!!

  • Al Reaud

    Si, vuelven. Enbede de tener llero en su sangre, tienen cobre. Se parecen que no son domisticados poer el video.

  • Irene

    Yes, Dave, they tell us the crab survives. What eles could they say?? But it’s still a lie. 10 to 15% of those marvelous creatures die from this procedure. Why can we farm thses valuable sea creatures instead of robbing nature? People are rapidly destroying this earth and all the living things on it!!!

  • Sydney

    (It came across the bottom of the screen ‘have you seen a horseshoe crab? Go to pbs.org Since I can’t find where to tell about it, I’ll leave my comment here.) I was in Biloxi, MS in July of 2008 and saw 2 horseshoe crabs on the beach one morning. I didn’t know what they were and couldn’t find out anywhere. I was so excited to see this program! I had been referring to them as the ‘prehistoric sea creatures’ on the beach…very cool to find out they really are prehistoric sea creatures! Too bad about the ones that die because of the bleeding process. you would think they would take less than 1/3 of their blood, maybe 1/4, and have more of them survive.

  • amanda

    while in florida my grandparents saw a whole bunch of these horeshoe crabs on the beach mating. and then we saw that show tonight and realized how big of a deal it was :)

  • Madeleine Godin

    This Nature Show was especially interesting and the blue blood-letting was unforgettable. Life lesson here: from the earth’s possibly ugliest creature comes a means to save Humanity. Thanks – MGL

  • ruth

    are the red knots still alive ? me and my mom want to know

  • Rejane Williams

    This is a wonderful thing.It will be a great help for us humans.
    Yes some die but it sure beats having been sold to be eaten.

  • frank d. mayer, jr.

    terrific program; loved it.

  • B.J.

    Is the 15% death rate cited only those that occur during the blood letting? If the industry profiting from their blood is providing the statistics, I would have little faith in their veracity. Does the 15% represent deaths that occur during the blood-letting? If so, who determines how many survive after being thrown back into the water after the procedure? Barbaric. But yes, the fisherman’s tearing them apart for eel bait is even more so…

  • Cherese Cobb

    I don’t believe the horseshoe crab is the world’s ugliest creature. It may be our most beautiful tie to the prehistoric era. While 13%, 86% live, die, those who live have given humanity the greatest gift the ability to live and for society to grow. To say that they bleeding them is a waste, only undermines what they are doing for us.

  • mike durliat

    Who are the company’s that are selling the blood?

  • Tom (former “Bleeder”)

    I’m not sure where the 10-15% mortality rate came from. I worked for years at a company called Associates of Cape Cod as a “Bleed Crew” member, and we rarely had casualties related to the actual bleed process approaching double digits. In fact each days “collection” was counted, sorted, and accounted for when we dropped them back in the water. Those “crabs” that arrived wounded (ingesting fishing hooks and line, impacts from boats, etc…), or had been previously bled (you’d see a scar on membrane) were not bled. An average male would produce about 20-24 ounces (two jars), and an adult female (larger than the males) would go 20-36 ounces 2 to 3 jars). The blood was processed twice to assure that none was wasted. Remember that in the coastal areas that these ancient creatures mate, they compete directly with shell fisherman, and are considered a nuisance. Many coastal towns still have bylaws that provide bounties for their destruction, and many are killed for bait, or just to get rid of them. Although humans get the better end of the deal, the harvesting of limulus blood is not the shop of horrors it’s often made out to be. From a purely economic perspective, the “crabs” are treated as a renewable natural resource, not an expolitable gift from nature. I’ve always been fascinated by these creatures, and my years in the “Bleeding” industry did not diminish my respect for them, or concern for their preservation.

  • Renee

    I work for the company mentioned in the video. I agree with the comment left by tom. It is not the bleeding process that causes the 10-15% death rate, this is the amount that die because they come in wounded already. We do not bleed any crab that is wounded. If it has a visible injury, bleeding or looks to have been bled recently (a return crab) then it is set aside and not bled. The crabs are checked over several times for injuries… during the washing and separation of males and females, during the racking and prepping process and again right before they are actually bled.

  • Carol

    I thought this was one of the most interesting shows I’ve seen in a long time. It’s amazing how everything is interdependent on each other. It definitely made me think about the balance of nature more. What a truly incredible thing!

  • aman

    I am a shellfisherman and i harvest them each year when they are mating.What most people don’t know is thier are millions and millions and millions of horseshoe crabs.People assume their are not that many of them because they mainly come ashore in late spring at night on a high out going tide for a period of an hour or so to mate.

  • Thomas Ortiz

    My question is if I wanted to buy some blood how and where can I buy it? Also would there be some kind of health benefit for taking out injecting this blood into our the human system? If this is so much of a wonder blood why can’t we use this as a health supplement to the public. So if this blood can kill ECOIL if there where a supplement safe for human comsumption would I ever get sick becasue the blood will kill the virus or bacteria in my body so in thoery my imune system can fight off colds and flus better.

  • Cindy

    My question is, how much blood doe a red knot consume?

  • boss

    that’s like all most all there blood.

  • Suzanne

    Thomas, if we made this “product” available to the masses, the death rate would likely RAPIDLY rise beyond the ~15% due to consumer demand. We already subject more than enough of our world’s species to our greedy demands of more this and better that. I think these crabs are already doing more than their fair share. If you are sincere, perhaps you should look into creating a farming operation so that such a thing could maintain sustainability, although I feel that most, if not all, species are compromised when farmed and lose viability in the “product” they were/are providing. Fascinating stuff though. We are all, big or small, here for a reason.

  • matt

    The blood cannot kill bacteria or viruses. The blood has enzymes that cause it to clot in the presence of a particular class of compounds present in the cell walls of gram negative bacteria. These compounds are called “endotoxins.” Our own immune system evolved a sensitivity to endotoxins too: they cause our bodies’ temperature to rise resulting in fever. That is why rabbits were previously used to test for the presence of endotoxins. Inject the rabbit with the drug and check to see if it gets a fever. A very crude way of testing. The lysate extract from horseshoe crab blood gives far more consistant and repeatable results and it is far more sensitive, giving the manufacturers of injectable drug products greater assurance that their drugs are free of endotoxins.

    Injecting the blood into your body would likely not be good for you. The horseshoe crab circulatory system might be able to deal with clots, but having clots floating around in our blood usually means a blocked blood vessel which if it happens in the brain or heart is often fatal.

  • James

    In addition to what Matt just said, injecting or otherwise introducing the horseshoe crab’s blood into our (human’s) bodies would likely result in our own immune systems attacking it. After all, our bodies can not even tolerate dissimilar types of blood (A,B,O,+,-,etc). The fact that it is copper based (which gives it the blue color) rather than iron based further supports the fact that it would not be compatible with our bodies. Due to the nature of their blood I would also expect, as Matt does, that their blood would quickly clot upon introduction to a foreign environment like our bodies resulting in a heart attack, stroke, and/or death.

    If someone like Thomas thinks this might be somekind of “miracle” cure and would like to inject themselves with this stuff, go right ahead and try it. I will be eager to hear the results! I can see the headline now, “Man Injects Self With Blue Blood Expecting to Become Royalty, Family Mourns.”

  • P.M .Downey

    Horseshoe crabs come ashore to spawn in season along our Long Island shores. The females are harvested for eel bait (filled with eggs before given the opportunity to spawn). The local limit is 200/day — 1400/week (if anyone counts!)
    Is there an opening here for expanding harvesting and return of HSC for medical purposes? It could greatly benefit the survival of the dwindling numbers, and also help the local bayman who sees his activity as his historical right to earning his living. Certainly an end product of $1,500/quart of HSC blood as opposed to cents per pound for eel bait has to be an incentive. Especially if extinction of the species is a consideration, in which case even the cents per pound would disappear.

  • dane cook

    dude when they say much they mean alot probably and do these people realize that these animals are going extinct and the whole reason that they have such special blood is because for over 300 million years these creatures have been living peacefully and now us people are killing them for no good reason

  • fuzzybear chicago

    where are horseshoe found ? AND HOW COULD a regular person as myself find them ?

  • JimBob

    Thank you, Dane Cook, for your very intelligent, coherent, perfectly-grammared insight into the horseshoe crab history and how “us people” are killing them. Comments like yours are so helpful to the cause.

  • HarvardGrad

    This earth was made for humans. So as humans we own everything. It is only a matter of push and pull that determines what we use these animals for. Regardless we can not let the Horseshoe Crab become extinct because we need its blood. And the reason researchers are not looking into a finding a substitute for the Red Knots rather then Horseshoe Crab is that because there is no money to be made in it. Fishermen will by the Horseshoe Crab substitute. As fro the birds there is this cool thing called bird feed that would work well.

  • 13genFloridian

    The horseshoe crab is in no danger of extinction. In fact, where I live, our local coastal restoration project has had 3 phenomenal successes. First, the cultivation of mangroves has reversed coastal erosion. Second, the water quality of the bay has improved to the point that consumption limits on local seafood have been lifted. Finally, third, the horseshoe population has increased more than 100 fold in the last 5 years. Unfortunately for harvesters, the crabs breed in protected mangrove preserves.

  • ghudson

    after yearly trips to Reed’s Beach here in NJ just to see what was masses of egg-laying horseshoe crabs and the mass migration of shore birds, I can tell you it is a fraction of what it was 20 years ago. We used to see the crabs in a swath 5-10 feet wide and miles long and piled on top of each other with millions of birds feeding on the eggs…that is no more.

  • JacquieMi

    This must be terrifying for the crabs. And, I agree with those who’ve noted that death rates cited by industry should be taken with several grains of salt.

  • Rivera

    Youre “borrowing” someof the crabs..because they dont all survive.These crabs are as they said “remarkable” so is their blood! They should be left alone..

  • m.shakeel

    What a wonderfull creature that i have never seen before, and is beneficial for human being we must be thankfull to creater and scientists who introduced, researched—-

  • Jay

    I have to confess that I really can’t understand how some people can so instinctively look at all human activity as exploitative. I mean really! It’s just mind boggling to read some of these comments hyperventilating about how we’re slaughtering these crabs, or we have no right to engage in activity that might harm them. Do these people not understand that, as part of the eco-system, we are just doing the same thing every other species does? Lions eat gazelles, and would eat them to extinction if they could, but nobody wails and moans about that because they’re just being lions. The same goes for every species on earth. We’re interrelated. We make use of each other. It’s not being greedy or evil or any of the other ridiculous accusations being thrown around here. It’s just the way the world works.

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  • Lisa W

    Who is interested in purchasing my horse shoe crabs for their blood for medical uses?

  • brian

    “lions…would eat them to extinction if they could” ..but they have no reason to. That statement just sounds ridiculous, no where else outside of the human world has anyone had a reason to or ever went on such overkill as humans when it comes to harvesting (fur, tusks, blood, blubber) or eating an entire species to extinction, because they don’t think like we do. They dont have greed. Most of them just take what they need for the moment and leave the rest, sometimes bury it for later. The ones that do hoard are so small (squirels, rats, etc) I can’t think of anywhere on the planet where one species has eaten something to extinction.

    Not saying lions are so innocent, but sounds like your trying to paint as monsterous a profile of other species as humans act because we are smart enough to know what we are doing and still do it. and not for food; for any reason from medical to just fun or fashion. if anything we should have the sense to feel guilt. try to tell yourself what you want, but there are over 7 billion of us and we’re the ones w/guns and seringes, i think were the ones who should tread lighter

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