Horseshoe Crabs | JONATHAN BIRD’S BLUE WORLD


Coming up, Cameraman Tim makes his debut as
a Blue World correspondent as he investigates one of the oldest animals in the ocean—the
Horseshoe crab! Welcome to Jonathan Bird’s Blue World! The Horseshoe Crab. It looks more like a walking helmet than a
crab, which isn’t surprising, since it’s not a crab at all. It’s more closely related to spiders than
to crabs. This animal has been crawling around on the
sea floor for a long time. In fact, the earliest known Horseshoe crab
fossils date back 450 million years! There are 4 species of Horseshoe crabs around
the world, but this one, the Atlantic Horseshoe crab, is found along the east coast of the
USA as far south as the Gulf of Mexico. The Horseshoe crab lives a quiet life, cruising
along sandy and rubbly sea floors, digging for worms and mollusks like clams and scallops. If they hang out in shallow water, there is
enough light to grow a beard of green algae. Sometimes they even become a moving substrate
for barnacles, mussels and other clingy critters. Many people think that the long tail called
a telson, is some kind of a stinger, but actually it has a much more practical use. During the summer when the water warms up,
the mating season begins. Males hang on to the females and follow them
everywhere until they are ready to mate. One of the biggest spawning aggregations of
Horseshoe crabs in the world takes place in the waters around Cape Cod. Because Cape Cod is basically a huge sand
bar, it’s shallow–and sandy–perfect habitat for Horseshoe crabs. I’m sending Cameraman Tim on his first assignment
as Blue World correspondent to check it out. Okay, we’re on Nauset beach in Cape Cod,
Massachusetts and I’m telling you, we have the coolest animal in the world. Tell me what this reminds you of? This horseshoe crab, it’s ancestors go back
almost 450 million years. What a fascinating little animal. If you look underneath he’s got ten legs,
his mouth and the reason he is called a horseshoe crab is because his shell, the head shell,
looks like a horseshoe. He’s got two eyes, two compound eyes on
the front. He is not happy that I’m holding him. He has come up onto the beach because all
horseshoe crabs, they are all starting to breed, and mate on the beach and lay eggs. Look at him…what does he remind you of? What movie? Fascinating. I’m going to let him go. There’s a pair coming in right now! You can see them everywhere. Those little black shadows all in the shallow
water here right now. And they’re all coming in. They have one male on the back of a female,
and they’re all heading into the shallow water. To learn more about the Horseshoe crabs, Tim
is meeting up with volunteers from Mass Audubon’s Wellfleet Bay Wildlife Sanctuary, along with
science coordinator Mark Faherty. So these guys are doing horseshoe crab spawning
surveys. And so this is a standardized method used
by organizations, volunteers, state agencies, federal biologists all up and down the east
coast. And the idea is, these are 5 meter quadrats
starting at the high tide line. And it’s just a standardized way to count
spawning horseshoe crabs. Horseshoe crabs come up to the water line
on high tides to spawn. They spawn in the intertidal zone as well
quite a bit on Cape Cod but this is the methodology that everybody uses so the data is comparable
across sites and across years. Here’s some action right in front of us
here. Look at that one! That one has a mussel farm growing on it’s
back. She hasn’t obviously been moving quick enough. They’re holding on for dear life. Look, one’s got the tail… This is the end of the spawning season…I
don’t think this is the A Team here! Oh wait a minute! That one is tagged! Did you guys read the tag off of this? Oh yeah, check these guys for tags as you
go. So this is a U.S. Fish and Wildlife tag. We put it on. It’s a great activity with school groups. It’s a great way to involve school groups
in the research that we do. So this is a mark/recapture project where
you put a uniquely-numbered tag on the crab and hope to find it again. So it gives you information on site fidelity,
do they come back to the same spawning site year after year, how much do they move around,
how long are they around, that kind of thing. And so this is a nice find because we don’t
do a ton of tagging at this site. We do it sort of opportunistically. So this is a male, and you can tell because
they have…their front legs have these sort of boxing glove-looking things called pedipalps,
and that’s for holding on to the female. The males also have a really concave front
of the shell for kind of riding along the female’s back, and then their mouth is here
at the base of the legs. They have these book gills, these flaps for
their gills and they haven’t changed very much in 480 million years, so I guess it works
for them. They always tell people don’t hold them
by the telson. I’m sure there’s kids out there like me
when I was growing up on the beaches in Plymouth and I thought it was stinger. “Ooh, the stinger watch out!” but it’s
totally harmless. Don’t pick them up by the tail. It’s to help them (because it can break
off sometimes) it’s critical for helping them flip themselves over if they end up on
their back. They have all kinds of eyes. They have more than just these two. They have light receptors even on the telson
and other places. There’s one right there. Look at this! Look at that! They’ve all got tags! Let me know when you’re ready. That does look newer. 353399. This is what we came for right here! This is happening right now! Check it out! You can see this great big lump in the water
in the front is the female. She has dug into the sand and she is laying
the eggs right now. The male, who is attached to her back, he
is waiting for the eggs to go into the sand, and he can fertilize them. She’ll get up and she will move along and
she’ll dig back down and I mean, this is what we came out here for, to see this. And this is what surveyors and Mass Audubon
is looking for is this little action right here. That’s what it’s all about. Horseshoe crabs are something I have seen
on my dives here in New England ever since I first started diving. They’re animals that many people take for
granted. But I learned a lot about the Horseshoe crab
from Cameraman Tim’s investigation. And as long as they continue to spawn here
in the waters of Massachusetts, hopefully this enigmatic species will be around for
another 450 million years in the Blue World. If you are a fan of the Horseshoe crab and
you would like to volunteer for a Cape Cod survey, contact the Mass Audubon Society at
the link in the description. And don’t forget to subscribe! And check out our “merch” link in the
description for some Blue World swag!

100 thoughts on “Horseshoe Crabs | JONATHAN BIRD’S BLUE WORLD

  1. I didn’t want to put the times today cause- I’m freaking lazy today so lol

    But this was awesome. I’ve always wanted to know more about horseshoe “crabs.” I didn’t even know they weren’t really crabs. Jeez science’ll trick ya

    Also Tim did amazing

  2. In college I had a biology class where we got to bring sea creatures in like the Horshoe crab. Those guys are my favorite animals in the whole ocean 🙂 they’re so friendly and cute, it was a lot of fun learning about them!

  3. Dinosaurs: We are the oldest known creatures ever!

    Horseshoe crabs: Hold my salt water

  4. Great job Cameraman Tim, looks like they took our advice and gave you your own segment! I totally forgot about the Horseshoe crab so its nice to have a crash course about them. By the way Tim, I know you were thinking that the crabs looked like facehuggers from Alien. I'm a nerd so it was obvious to me, lol. Me personally, I think they look more like Kabuto from Pokémon (look it up, you'll get it). Looking forward to your next segment Jonathan and Tim! 😀

  5. Hi I'm new here and subscribed immediately!! Im a huge fan of the ocean and had a dream to scuba dive since I don't know I have a dream to dive with you but I don't know if my parents will let me but keep up the good content!!! 😀

  6. Horse shoe crabs are one of my favorites. They are so unintentionally comedic. Like that escape of the flipped one at the beginning. 🙂 1:43

  7. I LOVE YOUR CHANNEL AND VIDEOS ❤️??? Especially the red sea dive becuase i dived there and saw shark and thousands of lionfish and turtles ? and blue spotted stingrays

  8. Hi Jonathan and Blue World Crew!

    Always a fan of all your videos, and here's hoping you swing by Puerto Rico when you get the chance! We have cool airplane wrecks in Aguadilla out in the West and many things to see in Mayaguez and Ponce. We also have two Bioluminescent bays, one in Lajas and one in Vieques (a small island off to our east side). Maybe you can do a video on Dinoflagellates and how they work to create these bays!

    Thanks for another awesome video!

  9. Hey Jonathan, boy do I have a story for you! It was the year, 2014. I was 11 years old. I was blue crab fishing off a bridge in Rehoboth Beach, Delaware with my boy scout troop as the sun set. It was a beautiful evening. About 45 minutes into it, I spotted a huge snapping turtle swim through the reeds and go under the bridge. I dropped my net and went down to go after it. Once under the bridge, I realized that it wasn't a snapping turtle, but a giant horseshoe crab! To say that this thing was massive, is a bit of an understatement. It was humongous! According to Google, female horseshoe crabs grow up to 18 to 19 inches from head tail while males grow up to 14 to 15 inches. This thing was at least a whopping two feet (24 inches) long! Must have been a female! But man, what a Whopper! I dove into the shallow water after the giant and grabbed it by the back of it's shell! It was flipping its long spiky tail everywhere to try and dislodge itself from the grasp of my hands but it was no match! I was dedicated to landing this giant! It took every ounce of strength in me to haul it up while it was rapidly jabbing its giant Spike at my face. I carried it up, back to the bridge where every scout was in awe! Some of them were confused at the mythical creature because they had no idea what a horseshoe crab even was! We all got our phones out to take pictures and videos. This thing was massive! I've caught horseshoe crabs before but I've never caught one this big and I'll never forget this incredible catch! I wish I could show you the pictures. Also, beautiful video!

  10. They sure do use their tail very well. I initially thought it was a stinger or some kind of hunting device, but no!

  11. That's amazing. They are amazing. Their way of movement is fantastic to watch, a kind of swim walk motion.

  12. i love how they dont even try to pinch people when they get picked up… what a completely harmless creatures

  13. can you imagine going to a bar to pick up some hot ladies and a giant picks you up and interrupts? I would be cranky, too.

  14. I have been watching this channel for 4 years but I was really young and didn’t know how to subscribe and stuff but now I subscribed 😀

    What happened to the intro? Hi I’m Jonathan Blue… and welcome to my world! or something
    I miss that ):

  15. They are the one of the most helpful creatures we can find, it's just some people don't aware of it yet. Their copper-contained blue translucent blood is playing a great role in testing new medicines whether the medicine is contaminated with bacteria or any other infected materials.

  16. I'm surprised you didn't mention their copper-based blue blood. "Unlike vertebrates, horseshoe crabs do not have hemoglobin in their blood, but instead use hemocyanin to carry oxygen. Because of the copper present in hemocyanin, their blood is blue." [Nature] Also, their blood sells for $15,000 a quart to researchers and even more to the pharmaceutical industry.

  17. I’ve got a question for you. Was the sound in the part where the horseshoe crab flips over natural or was that some foley work?

  18. Did you know that some people are harvesting their blood recently? Pretty sad cause it can lead to over exploitation, but quite revolutionary in the medical industry.

  19. ancestors of the horseshoe crab has outlived the dinosaurs, who lived for 60-230 million years, while the horseshoe crab has lived over 450 million years… BOI!

  20. It's illegal to even touch a horseshoe crab in New Jersey. It's because a Pharmacuetical company hunted them to near extinction.

  21. omg horseshoe crabs ..i remember when i was a kid everytime i read books about dinosaurs or some kind of an ice age scenario, that cute creature always in the stories.. nice.. but can you eat them? they look like a giant tadpole though with a mix of shrimp. but still cute..????

  22. Horseshoe crabs are the closest living relatives to the Eurypterids, also known as the sea scorpions. I think they might also be the closest living relatives to Trilobites, but I might be wrong about that.

  23. They exist for so long they've made themselves into the perfect inedible creature. . . yet some lesser humans still hunt those for uh. . . eggs.

  24. What is being done to repopulate, protect, and ensure they get off the endangered list? Is there anyone I could contact about the Tri-spined Horseshoe crab / Chinese Horseshoe crab (Tachypleus tridentatus) or some place I could get more info on what is being done to keep them from going extinct?

  25. My marine invertebrate biology class is learning about arthropods now, so it's cool to observe the behavior of horseshoe crabs in your video. Thanks for your video!

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