Why Are There No Sea Snakes in the Atlantic?

Why Are There No Sea Snakes in the Atlantic?

Thanks to Brilliant for supporting
this episode of SciShow. Go to Brilliant.org/SciShow to learn more. [INTRO ♪] Sea snakes are the most common group of marine reptiles in the entire ocean, with almost seventy individual species. But despite their impressive diversity,
none of them live in the Atlantic Ocean. Which is weird, and also nice!
There’s a whole ocean with no snakes in it! But also there’s an entire ocean of snake food and
living space out there, so what’s going on? The answer lies in their evolution, their biology,
and a weirdly “dry” part of the ocean. The first reason is deceptively simple:
modern sea snakes didn’t evolve in the Atlantic. All sea snakes alive today evolved in a part of the Pacific known as the Coral Triangle and nearby regions, with most species evolving in the last
two and a half million years. So they might not have started in the Atlantic, but they’ve had millions of years to theoretically move there and establish new populations. But they haven’t, in part because it’s a pretty big ocean for such little reptiles. Only one species of sea snake, the yellow-bellied
sea snake, lives in the open ocean. Most of the others only live in
near-shore shallows. The yellow-belly is the only species that
would have much chance of making it to the Atlantic. But each of the different ways it could even hypothetically reach the Atlantic has its problems. Like, going around the tip of South America or Africa might be too cold. Yellow-bellied sea snakes need temperatures above 20 degrees Celsius in order to be toasty enough to breed. And too far below 18 and they’ll flat out die. Given an annual mean ocean temperature of less than 17 degrees off the coast of South Africa, that’s a no-go. Yellow-bellied sea snakes actually can live directly south of Africa, but it might be that the ocean is too cold just west of there, so they still couldn’t make the whole trip. Oddly enough, going around Africa
might also be too dry. Sea snakes can’t drink salt water. Instead, they drink a thin layer of rainwater that floats on the surface of the ocean after storms. Yes, this is a thing. That’s wild. But the southwest coast of Africa includes the Namib Desert with its infamous Skeleton Coast. This region may go years without rain,
even out at sea. Sea snakes going this way could
become dehydrated and die. And they might not have any more
luck trying to go the other way, where
North and South America are the obstacle. Millions of years ago, there was an open corridor between the Pacific and the Atlantic in what is now Panama— a much warmer route than rounding the southern tips of Africa or South America. Trouble is, the isthmus of Panama formed long before sea snakes evolved, blocking them from simply swimming from
one ocean to the other. We humans have opened that passage back up in the form of the Panama canal. And there have been reports of individual sea snakes on the Caribbean coast of Colombia—which presumably made the trip through the canal. Even so, scientists think it’s unlikely they’ll establish an actual breeding population via this route. So in the end, even though it might seem like the Atlantic could be a nice home for the sea snakes with warm water and tasty prey, their biology and evolutionary history put that possibility pretty much out of reach. If you’re the kind of person who wonders why certain reptiles never moved to certain parts of the ocean—well, you are as curious as we are. If you want to keep up your streak of learning new things, you might enjoy the daily challenges over on Brilliant.org. From stats to electricity to computer science, there are fresh new challenges every day. And whether you’re commuting or just relaxing at home, they give you a fun, bite-sized way to learn, apply, and master new concepts. And if you like what you learned from a given challenge, there’s a more in-depth course connected to each one. And they’re even free—but Brilliant’s premium members get access to the entire archive of challenges if you want to catch up. The first 200 people to sign up at Brilliant.org/SciShow will get 20% off an annual premium subscription. So if that sounds up your alley, click on the link in the description, and thanks for supporting us. [OUTRO ♪]

Randy Schultz

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100 thoughts on “Why Are There No Sea Snakes in the Atlantic?

  1. SciShow says:

    Go to http://Brilliant.org/SciShow to try out Brilliant’s Daily Challenges. The first 200 subscribers get 20% off an annual Premium subscription.

  2. Uneti Tree says:

    Well… Climate Change will bring them in the Atlantic sooner or later

  3. Charles Bronson says:

    Shiat I aint complaining ?

  4. Mark Garin says:

    Failed to mention that if the non-lock path between the Pacific and Atlantic is completed that may allow them to migrate in numbers. Perhaps the lock structure of the Panama canal and issue that most fish in the Atlantic don't what they are and are likely to try and eat them, not realizing they are poisonous, will still kill a bunch of single snakes off.

  5. Jeremy Byington says:

    Awww. We should intervene with the natural order of things and just drop a bunch of sea snakes in a habitable spot of the Atlantic.

  6. Ersin Avseren says:

    Thanks for the video. Now, Florida men will have sea snake pets and release them to gulf. See you in 5 years!

  7. Kevin O’Brien says:

    I thought St Patrick dove all the snakes from Ireland into the ocean.

  8. AJ G says:

    NZ doesn't have LAND snakes but we have SEA snakes. Yellow bellies are shy to come on land but they're still washed up.

  9. Mister Awesome says:

    I hate your logic.

  10. Kairi Suzuki says:

    I love how volutionary history and physiology can explain the mystery about their hanitat range❣️?

  11. Rodger Castro says:

    I'm not the only one who read "Attack of Atlantic sea snakes" right?

  12. S. Nonaka says:

    Puff addaer lives on the skeleton coast

  13. Pepe Le pew says:

    What if I throw some in there

  14. Hoang Mai says:

    Hi Hank. Where could I get access to the world map at 0:50? It looks great!

  15. SteveVi0lence says:

    Too cold and not many islands

  16. Liam Walton says:

    What about snakes near the Atlantic simply evolving into sea snakes themselves? Instead of the ones already existing trying to migrate.

    Wouldnt be hard for snakes in the swamps of Florida or the Amazon to test their seafaring legs

  17. HenryManson says:

    interesting, BUT having around 1:30min of a 4:20min video as pure commercial is just maddening outrageous!
    i hate these integrated commercials sooo much -.-

  18. Demetrius Middleton says:

    First, I appreciate videos like this. But it's slightly frustrating when they give scientific evidence for 75% of the video, and then get to the part where they say even though we seen them off the coast of Columbia or at the canal we just think it's going to be unlikely but it would work, without giving any scientific information as to why

  19. Bernie Bro says:

    Ok then, now my mission in life is to buy a boat and spread populations of sea snakes to islands and coasts across the Atlantic and Mediterranean

  20. Saartjie_69 says:

    1:45 Ja, Suid Afrika see water is fokin koud…

  21. K Cu says:

    Honestly it might change with the way we're moving species around

  22. Jane Doe says:

    When you click on a video thinking:

    "Huh, I wonder why there are no snakes at our shores?

    And part of the answer is:

    "It's because your shores are literally the Namibian Coastline"

    I do enjoy surprise learning things that make Namibia interesting. I never see it coming 🙂

  23. Sayan guria says:

    Because atlantic sucks

  24. T1Oracle says:

    Now some idiot is going drop a bag of snakes in the Atlantic…

  25. Jimbo Palmer says:

    A tongue twister for mother nature: She slakes sea snakes near the seashore.

  26. catch tone says:

    Let's get a bunch of em together and let em mate in the Atlantic. Ya know give em a chance

  27. Peter Fraser says:

    Suiz canal

  28. The Hiking gamer says:

    Couldn't they evolve on their own in the Atlantic ?

  29. Juan Diego Vasquez says:

    Is Brilliant.org available in Spanish?

  30. Jannie Kirsten says:

    To pronounce "Namib" properly, place the accent on the "Na-" syllable instead of the "-mib" syllable.

  31. Jezebel von Tex says:

    I pretty happy with not having any snakes in our oceans around here! So you better NOT be telling them our ocean is full of snake food!

  32. no1bandfan says:

    I guess they’ll just have to evolve legs so they can go over the land. Wait…

  33. christosvoskresye says:

    Do one on why the Burmese python never made it to south Florida in spite of the Everglades being apparently ideal for it.

  34. Vince C says:

    One of them is living in my trousers

  35. -Double Negative- says:

    Pretty sure I saw one in the Chesapeake bay 7 years ago.

  36. Dean Dazzle says:

    Blaze it, I guess.

  37. Generic Username says:

    So what you are saying is we only need to focus on one ocean to eliminate sea snakes.

  38. Flightboss33 says:

    THERE ARE SEA SNAKES??!!!?!?!?!

  39. Justin Y. 2.0 says:

    Most Sea snakes are actually quite tame

  40. Sondre says:

    Thanks to global warming we might soon have more diversity in the whole world 😀
    People living in Europe will not just enjoy malaria mosquitoes and killer bees, etc. coming from Africa, but snakes from the atlantic to! :)))))))))))

    I'm pretty glad I live now and not in a hundred years time ^_^

  41. Junior Mynos says:

    They'll strive on lion fish

  42. Samuel Matheson says:

    Guess who found out hes allergic to jellyfish today

  43. morelli tech says:

    It's because the Moray Eels built a wall

  44. Pete 952 says:

    Any sea snakes that make it over to our side, I hope divers will nail them. I'm all for living things, but that is an invasive species that can kill you. No more lion fish horror stories.

  45. Jeremy R says:

    im in florida seen like 3 sea snakes…

  46. Lucas Brothers says:


  47. Upright Ape says:

    Don't worry……weirdos in Florida will be releasing Sea Snakes into the wild any day. Thank you once again, Florida Exotic Pet Trade.

  48. Craigo S says:

    Why couldn’t they come through the Mediterranean?

  49. ibelieveicansoar says:

    ? Have you done a video on why there are no cacti native to the Old World? (Well, there's one Rhipsalis in Africa, but it surely originated in the New World a.k.a. the Americas.)
    On the other hand, all aloes are native to the Old World.

  50. Snorting Dandruff says:

    But about a year ago you said the Panama Canal existed when Neanderthal did during the ice age…yet now you said it didn’t so sea snakes could not have passed through

  51. Lib Tard says:

    With all due respect, this is not true at all!!! Have seen several in the Dry Tortugas and Key west over the years. As well have seen several in Long Key as well. Many have been seen, so clearly they must be breeding.

    We feel they must be coming thru the Panama Canal??? They were definitely sea snakes, you can not mistake that tail.

  52. ÅTīS Tīcc Fük M.F. says:

    Eons pbs im sorry little one

  53. King Hip-O says:

    No sea snakes in the Atlantic until some idiot from south Florida buys one in the black market for their home aquarium and then releases it in the wild when it gets too hard to maintain.

  54. Micheal Wolfe says:

    Somebody’s gonna release these snakes in the Mediterranean after watching your video , lol ?

  55. James Otto says:

    Yeah no seasnake in the Atlantic, only Atlantic snake 🙂

  56. dan fg says:

    Any satanist worth his salt will be dropping sea snakes into the Atlantic Ocean after watching this video

  57. Through Coloured Glasses says:

    Like. How do you even come up with this question? Are sea snakes a thing anywhere but specific jungle regions?

  58. van hill says:

    Atlantic discriminates against reptiles….

  59. weshard1 says:

    Why are Otariidae (eared seals) absent from the North Atlantic?

  60. Otto Von Bismarck says:

    Aquatic Ireland.

  61. LOL Science says:

    My grandma forbid me to swim in the Atlantic because she swore she saw a snake…

  62. William Strickland says:

    Wow how they drink is awesome. I never knew that. Thank you very much for the video and teaching me something new today

  63. Beth Bartlett says:

    Why St Patrick of Course.

    Ireland is in the Atlantic – you so Silly. ?

  64. helterskelter416 says:

    i'm going to buy a lot of sea snakes and just put them in the atlantic.

  65. Bernhard Jordan says:

    That can be corrected

  66. johnnyhb89 says:

    Crazy sea snakes haven't been around much longer than human being ancestors. Snakes have been out 100 million years, seasnakes 2.5 million.

  67. Wilhelm Dietrich says:

    Sea snakes never heard of the Suez canal. Basic snakes ?

  68. liz Swedlund says:

    What ideologue you are. Anyone doing any objective research knows that evolution has been categorically disproven. With one phrase I can ruin it , ,Carbon 14 in coal and dinosaur Bones.

  69. Zeebaneh says:

    This hasn't been proven to be millions of years… Am I the only person who questions evolution???

  70. DostLP says:

    Let's revisit this video in some years and see, if a troll helped some sea snakes to get over there…

  71. Boco Corwin says:

    "Curse you, isthmus!" cried the sea snake.


  72. Tired_David says:

    That's fine. We don't need them. They can stay right where they are.

  73. Sail Oria complete refit says:

    I think the Atlantic Sea Snakes "evolved" into Homo Sapiens over the last 2.5 million years! LMFAO

  74. Camilla Whatcott says:

    Drinking a thin layer of rainwater on the top?
    Brb gotta do some weird googling again

  75. diceman199 says:

    Didn't know about the rainwater thing. I got to see a sea snake in the wild once. Swam by about 10 feet away from me.

  76. Zachary Stuber says:

    So could we technically bring them over and release them in the Atlantic ocean?

  77. alled zebu says:

    Some random central american troll:
    "Ohh i see you have the atlantic ocean remain sheltered and free from marine snakes for the longest time, that's very nice"…

    "It would be such a shame… if… someone"…


    Just in case! Am just kidding, not ever intending to do something like this, nor do i endorse or encourage this…

    But you gotta admit, you only need one person, just ONE stupid enough person with enough desire to see the world burn and the geographic advantage for this to happen xD

  78. Ribeye Rare says:

    What keeps sea snakes from having a population in the Atlantic? Me. I live too close to it. That’s not okay.

  79. Palindrome says:

    The Sea Without Snakes: An Isthmus Miracle.

  80. J Carlo Paguada C says:

    Hmmm, I've seen some in the Caribbean ?

  81. J Espinola says:

    i thought it said "Attack of the Atlantic Sea Snakes" lol

  82. Metru Nui says:

    meanwhile on Australia..literally sneks everywhere

  83. gass it club says:

    there are snakes in the Atlantic ? is this a flat earth thing

  84. Quirt Manly says:

    A fact that I can live with!

  85. Colt Perfect says:

    I’ve seen a sea snake on the Atlantic side of Florida while I was scuba diving

  86. ernic bodden says:

    That is bit exactly true, I am from Santa elena Roatan, an island in the Caribbean we have sea snakes black and white stripes like zebra there.

  87. ernic bodden says:

    Not exactly true I meant, Santa elena, Roatan island in the Caribbean has black and white striped sea snakes

  88. Barry Kelly says:

    The main pic looks a lot like an eastern kingsnake.

  89. B D says:

    Does the Caribbean not count as the Atlantic because I've definitely saw a white snake and not just the band from the 80s

  90. Slartibartfast says:

    Sipping fresh rainwater off the surface of the sea is so poetic, what beautiful creatures.

    No wonder Coleridge included them in his poem:

    Beyond the shadow of the ship,
    I watched the water-snakes :
    They moved in tracks of shining white,
    And when they reared, the elfish light
    Fell off in hoary flakes.

    Within the shadow of the ship,
    I watched their rich attire :
    Blue, glossy green, and velvet black,
    They coiled and swam ; and every track
    Was a flash of golden fire.

    O happy living things ! no tongue
    Their beauty might declare :
    A spring of love gushed from my heart,
    And I blessed them unaware :
    Sure my kind Saint took pity on me,
    And I blessed them unaware.

    The self-same moment I could pray ;
    And from my neck so free
    The Albatross fell off, and sank
    Like lead into the sea.’

  91. Barry Goldwater says:

    To me this proves and disproves evolution at the same time.

  92. B Brunson says:

    It’s kind of like complaining about the lack of mosquitoes.

  93. Timmy Dirtyrat says:

    Why don't they just walk there?

  94. boulderbash19700209 says:

    How about Suez canal?

  95. just me says:

    I live in Florida and I had no idea sea snakes were thing. I've seen them in ponds but I thought eels were the only snakeish thing in the oceans

  96. just me says:

    Do sea snakes bite? Are they poisonous? I'd Google it but I know I'd get caught up and end up spending at least a 3 hours researching them

  97. TheDragorin says:

    so what you're saying is, i should take a truckload of seasnakes and throw then in the atlantic?

  98. Ken O says:

    So is there a way, someone stranded in a lifeboat on the ocean, to drink the rain water at the top without consuming a lethal dose of saltwater?

  99. Dan Erickson says:

    Now I know where the term yellow bellied comes from. A yellow bellied snake? Who would have thunk it.

  100. Krzysztof Czarnecki says:

    Who else thought it was "Attack of the Atlantic sea snakes"?

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