10+ Animals That Don't Have Most Important Organs

Horses live without a gallbladder. Many animals, including humans, need this organ to store bile, a smelly liquid stuff produced by the liver to help the body process fats. Lots of predators need it because they eat in big portions at once, so bile helps them digest food more easily. Horses, on the other hand, need to constantly munch on grass in small quantities. That's why bile isn't necessary for them. Lungless salamanders live happily without, you guessed it, lungs. But unlike fish, which have gills to extract oxygen from water, the sallies take all the air they need to breathe directly through their skin. And they're not something extremely rare either. In fact, these amphibians are the most numerous salamanders in the world. On the topic of breathing, lots of snake species have only one working lung. In the process of evolution, snakes' internal organs became adapted to their body shape, and there's simply no space left for a second lung. As a result, in many of these slithery critters, the left lung has become so small it's not even functional. Spiders are well-known for their eight legs and multiple eyes, but the Kauai cave wolf spider is special because it doesn't have any eyes at all. It's very rare, living in an isolated cave area of Hawaii. Platypus is weird by itself, having the features of both a duck and an otter, and a potent venom to boot. What it doesn't have, though, is a stomach. There's nothing between the platypus' gullet and intestines. Animals need the stomach to break down food before it's processed in the intestines and goes out the other way. Cows, for example, have as many as four of them. But animals like platypuses and many species of fish don't have any use for this organ, and so they just dropped it. Lots of predatory animals, including our beloved cats and dogs, don't have sweat glands on their bodies. Humans cool down by sweating all over the place, while we often see pooches breathing hard with their mouths wide open. Because of this, they can't bring down their body temperature while eating or drinking, for example. Flatworms, among some others, don't have blood at all. They're small worm-like creatures that can live both in watery areas and in someone else's body, such as humans. Since they're parasites, though, you don't naturally have them, of course. Anyways, these critters don't have even a rudimentary circulatory system, so they don't need blood. Instead, they get the necessary nutrients directly through their body surface. There's not a single animal in the world, except human, that has a chin. You might argue that even many pets do have it, but in reality, they don't. Chin is a bone protrusion that goes forward and down from the lower mandible. No other animal has it. All they have is the mandible itself, which is flat on the bottom and goes straight back to the neck. Perhaps the most impossible creature in the world is a jellyfish. It doesn't have any sensory organs we're used to, like eyes, ears, and a nose. It has no skeleton, but most importantly, it hasn't gotten a brain or heart. Its body is almost entirely made of water. That's why, if you take a jellyfish out of the sea and put it on the shore, it will soon melt. At the same time, there's a species of jellyfish that can live forever in a safe environment. It just might be that jellyfish have given up their hearts and brains for the sake of other sea creatures, because octopuses, for example, can have multiple of those. The giant Pacific octopus, in particular, has 9 brains and 3 hearts. 8 smaller brains allow each of the animal's arms to move independently, while being coordinated by the bigger central one. And the hearts pump the octopus's blood, which is blue, by the way, to its gills and the rest of the body. Still, the champion in terms of heart numbers is a hagfish. It has 4 of those. These unsavory, lamprey-like sea creatures use one of their hearts as a main pump, having the rest of them assist it. Hagfish also emit slime that can fill a water bottle in just a few seconds, and sneezes when this slime gets into its nose. Remember the cows with their 4 stomachs? Well, any ruminant, such as an antelope, camel, or alpaca, has this feature. But the fact is that they still have one stomach, which is divided into 4 chambers, and the food moves about from one chamber to the next until it gets into the intestines. Surprisingly, catch-a-lot whales also have this stomach structure because they have teeth but can only bite, not chew. You'd expect that even if an animal has more than 2 eyes, they'd still be on its head. That's not true for horseshoe crabs. They have 2 eyes on the sides of their head, 5 more on the top of their shell, 2 near the mouth, and 1 on the tail. The latter is used as a photoreceptor. It catches the sunlight and tells the crab if it's day or night outside. Speaking of the eyes, many animals have a nictitating membrane, a kind of semi-transparent third eyelid that protects the eye while still allowing the animal to see. Humans seem to have had it in the past as well. If you look at the inner corners of your eyes, you'll see small patches of tissues where the membranes used to be. Although starfish have a mouth, they don't use it for eating directly. Instead, they push their stomachs out of their bodies and collect food from the sea bottom with it, then bring the organ back inside. Well, that's different. Starfish are also creatures with no blood or circulatory system, as well as lungs. They use their tiny tubular feet to pump water inside them and use it instead of blood. Pit vipers, as well as many other snakes, have a tiny organ in the pit of their head that allows them to detect their prey even at night. This organ acts as a heat sensor, so they can see warm-blooded animals, but not their own relatives, other snakes or cold-blooded amphibians. Sharks go even further with a special electricity sensor near their nose. Electricity travels well in seawater, and thanks to this sensor, sharks can feel electromagnetic impulses emitted by other animals from far, far away. Bombardier beetles may be small, but they're formidable opponents in nature. They have a special sack where they store a mixture of two potent chemicals, and when threatened, they let this mix go in an explosive reaction. Any bird or other predator unlucky enough to get in the way of this blast will be in trouble, to say the least. While humans normally have three types of light-sensitive cones in our eyes, allowing us to see hundreds of thousands of colors, mantis shrimp have 16 of those. Thanks to that, they can see colors simply unimaginable for humans. And they're also quite colorful themselves. Despite their beauty, though, they pack quite a punch. A mantis shrimp can even break the glass of a home aquarium. Pistil shrimps, however, beat their relatives in power because they close their big right claw with such speed that it creates a white-hot air bubble underwater. And it's literally hot. The temperature of this tiny bubble momentarily reaches almost that of the surface of the sun. Any prey close enough to the pistil shrimp's claw is knocked out at once. Finally, hippos don't get their skin burned in the blazing sun because they produce their own sunscreen. It's kind of a pink sweat that covers their whole body. And just a not-so-fun fact, hippos can also run almost at the speed of a scooter, so better not make it angry. You'll be chased by a slimy, slick, slippery hippo.