Welcome to brain Stuff, a production of iHeart Radio, Hey brain Stuff, Lauren Bogle bomb here. Every so often, yellow bellied sea snakes tie themselves in knots, but they, like all servants, must regularly shed their skin. But the process demands friction, and in the open sea it can be hard to find a rock or reef to rub up against, So the animals play contortionist twisting coils around coils, they peel off old skin in an acrobatic looping maneuver. The
exercise has a nice side effect. Barnacles, oysters and other tiny hitchhikers plague these snakes. To frequent sheds help keep their numbers down. If you're an armless, legless air breather, life in the ocean is fraught with challenges, yet the fifty plus sea snake species alive today use all kinds of amazing tricks to get by. A snake at sea is not automatically a sea snake. Lots of unrelated species
frolic in our oceans from time to time. Reticulated pythons, for example, will swim between islands along the coasts of southeastern Asia, crossing distances that could wear out an Olympian That doesn't, however, make them sea snakes. When naturalists talk about sea snakes, they're usually referring to two very specific groups of reptiles that are part of the Cobra family, true sea snakes genus name Hydrophenia and sea krits or lat cottona. We've already mentioned one of the former species,
yellow bellied sea snakes. Those oddball not tires are classic hydro feads. True sea snakes like these have sworn off of dry land altogether. Fully marine, they give birth to live young at sea. Terrestrial births just aren't an option. Hydro Feeds never ex the water voluntarily because they lack the wide belly scales that other snakes used to crawl over solid ground. Drop one on a beach in a poor creature would struggle to move under its own power.
Sea krates are a bit less streamlined, but they're more competent on land. They mate, shed and digest some of their meals outside the water. Equipped with the requisite belly scales, the animals are free to hit the turf, and like sea turtles, they lay eggs in beachside nests. But the similarities between these groups far outweigh their differences. All sea krets and true sea snakes have paddle shaped tails that help them zip through the water. They're also venomous, but
seldom kill human beings. The animals tend to be docile around people, and bites usually only happen when a snake feels trapped and stressed out. One banded sea kright fatally bit a man after a fishing net ensnared it. Most sea snakes inject their venom through hollow fangs at the front of their mouth rather than waste its ammo. A frightened sea snake will often administer dry bites striking its foe without releasing pressure venom, but give them a wide
berth just to be safe. Neurotoxins in sea snake venoms attack the victim's nervous system. Paralysis, spasms, and respiratory problems may occur as the chemicals do their work. Fish are the main food source for the vast majority of species. Sometimes it pays to let dinner come to you. The yellow bellied sea snake lies motionless at the ocean's surface, waiting for careless fish to take refuge under its coils before grabbing them. Other sea snakes drag fish out of
the cracks and crevices and coral reefs. Such hiding places are frequented by eels, the banded seacrite's favorite prey, while more rays can be dangerous. Game chrits immobilize them with venom and then swallow the creatures whole. A few species, like the spine tailed sea snake, eat only fish eggs. These specialists have tiny fangs, and some have exceptionally weak venom.
Caviar can't swim away, so there's no need to give it paralysis, but let a. Cattids and hydro feeds can't drink sea water, so they need to keep hydrated by other means. Sea krites have been observed licking fresh water droplets off of plant leaves when they come ashore and after storm. They sometimes gather on islands to drink from puddles. When it rains over the ocean, an interesting phenomenon occurs. New fallen drops congregate at the surface to form a
temporary and drinkable lens of fresh water. Yellow bellied sea snakes use those lenses to quench their thirst, zeroing in before the rainwater gets inundated with too much salt. Both seacrites and true sea snakes have valves that can seal off their nostrils and keep out water during dives. Some species are known to stay underwater for three and a half hours on end. None of these guys possess gills, though.
In twenty nineteen, researchers learned that the blue banded sea snake, a true species, uses intricate blood vessels on its head to pull oxygen straight out of the water. Not a bad superpower. Sharks, crocodiles, and some birds of prey will all eat sea snakes if given the chance to confuse attackers. The yellow lipped seacrite has evolved deceptive markings that make the end of its tail look like a second head. Pollution is another big threat, especially to snakes who swim
and feed near industrial sites. Long before humans started contaminating things, sea snakes had spread out across the Pacific and Indian Oceans. Two landlocked lakes in the South Pacific have their own resident species as well, just don't bother looking for them. In the Atlantic, Earth's second biggest ocean, is free of all sea snakes. Geography and climate may explain why the scientists think that the reptiles ancestors evolved in the Western
Pacific six to eight million years ago. By the time modern species reached the America's the Panama land Bridge between North and South America might have already closed up and cold water kills sea snakes so that have been unable to swim around South America's Cape Horn. Meanwhile, Africa's southeastern coast gets very little rainfall. Any sea snake foolish enough to hang out there would have had a difficult time
staying hydrated. Even survivalists do have their limitations. Today's episode was written by Mark Mancini and produced by Tyler Clay. For more on this lots of other curious topics, visit how stuff works dot com. Brain Stuff is a production of iHeart Radio. For more podcasts in my heart Radio, visit the iHeart Radio app, Apple Podcasts, or wherever you listen to your favorite shows.