The animal world is always full of surprises and fun things waiting for us to explore. The heart is one of the organs that most animals have, and it is also one of the organs that are of most interest to zoologists. The hearts of animals are not all like human hearts, and the hearts of each animal may be different, even beyond our imagination. Let's take a look at the most magical hearts of animals.
<h1 class= "pgc-h-arrow-right" >9: Fairy bee (Tsubasa) – the smallest heart</h1>
The fairy bee is a small insect of the orchid species, usually between 0.5 mm and 1.0 mm in length. The fairy bee contains the smallest flying insect in the world, with a body length of only 0.139 mm. Their lifetimes are very short, usually only a few days. Fairy bees are parasitic creatures that parasitize inside the eggs of other insects.
The fairy bee has the smallest heart of a known animal and requires a microscope to see clearly. Their hearts are not like human hearts, which have developed muscles, but a thin tube along the back, without veins and arteries. Thin tubes can beat rapidly and periodically, pumping blood all over the body.
<h1 class = "pgc-h-arrow-right" >8: Dog – the heart with the largest proportion of the body</h1>
Dogs are one of the best companions for humans, and many people treat them as their pets. But have you ever thought about the heart of a dog? How big is it? A surprising fact about the hearts of dogs is that the ratio of heart mass to body mass is the highest in the animal kingdom, reaching 0.8%, compared with only 0.6% for humans, elephants, mice, etc. Slightly lower than dogs are their ancestors, wolves.
<h1 class = "pgc-h-arrow-right" >7: Cheetah – the fastest-changing heart</h1>
The cheetah is a feline found mainly in Africa and Iran in Asia, and is considered the fastest animal on Earth. Cheetahs can reach speeds of up to 112 kilometers per hour, and it takes more than three seconds to run 100 meters, while the fastest human Bolt takes more than 9 seconds.
A key element of the cheetah's ability to run so fast is the change in the frequency of its heart beating. The cheetah is in a resting state, with a heart rate of 120 beats per minute, similar to a human jogging. The human heartbeat takes a process to break through to its limits, 220 beats per minute, while cheetahs reach their limits, 250 beats per minute, in just a few seconds.
<h1 class = "pgc-h-arrow-right" >6: Skunk – the fastest-beating heart</h1>
The smaller the body, the faster the heartbeat, which is a more common feature of vertebrates. Hummingbirds are the smallest birds with superb maneuvering skills and a very high metabolic rate, as well as a heart rate of up to 1,000 per minute. However, the smallest mammal, the Skunk (Suncus etruscus), has a higher heart rate.
The skunk is a rare mammal found mainly in Yunnan. Its body length is only 4cm, its weight is only 1.8g, and it feeds on small animals such as insects and earthworms, and eats food of about its own weight a day. The baby skunk's heartbeat reaches 1511 times per minute, more than 500 more than hummingbirds, beating 25 times per second, while the human heartbeat is less than 2 times per second (in a rest state).
<h1 class = "pgc-h-arrow-right" >5: Giraffe – the heart with the highest blood pressure</h1>
Giraffes are the tallest animals on Earth, and their hearts are nearly 2.5 meters from the head, which is taller than Yao Ming's height, so how to deliver blood to the head is a problem. To this end, giraffes have evolved larger hearts – about 0.6 m in size and about 11 kg in weight – but that's not enough. Giraffes have also evolved extremely high blood pressure, with near-heart blood pressure reaching 280/180 mmHg, more than twice as high as in humans. In response to high blood pressure, the left ventricular wall of giraffes reached a thickness of 7 cm. Giraffes also have a heartbeat of 170 beats per minute, and it can be said that giraffes have the strongest hearts in the animal kingdom.
<h1 class = "pgc-h-arrow-right" >4: Blue Whale – the largest heart</h1>
The blue whale is the largest living animal on Earth, weighing about 173 tons. The huge size also determines the huge internal organs of the blue whale. The heart of the blue whale is the size of a car, weighs nearly 400 kilograms, and can output about 80 liters of blood per beat, making it the largest heart in the animal kingdom at present. The blue whale's aorta reaches 23 cm, allowing a baby to climb through smoothly, and we can also stick our head into the aorta of the blue whale's heart to see how the inside of the heart looks. However, although the blue whale has the largest heart, its pulse is very slow, passing only a dozen times per minute, or even only a few.
<h1 class = "pgc-h-arrow-right" >3: Octopus – three hearts</h1>
Octopuses are mollusks with soft bodies that can pass through narrow bottle openings. Octopuses have a fairly complex nervous system and are one of the most intelligent animals, and they can learn to open the cap and take out the food inside. The octopus can be said to have nine brains, one in the usual sense of the word, and the remaining eight on its brachiopods. In addition to the nine brains, the octopus has three hearts, two gill hearts, and a whole-body heart.
The blood of octopus is blue because it contains a type of hemocyanin, also known as hemocynin, and the gill heart is related to the synthesis of hemocyanin. In addition to octopuses, most molluscs, as well as horseshoe crabs, also have blue blood. Hemoglobin has been shown to be more suitable for oxygen delivery in cold conditions. When the octopus swims, the whole body and heart are inactive and easily tired, so the octopus likes to crawl with eight brachiopods.
<h1 class = "pgc-h-arrow-right" >2: Wood frog – the beating heart</h1>
The wood frog is the only amphibian that can survive in the Arctic Circle and belongs to the same family as the forest frog. Wood frogs are mainly distributed in North America, and forest frogs are mainly distributed in Europe. Wood frogs generally breed in "spring ponds", a type of wetland that only appears in the spring.
Because their habitat is very far north, wood frogs tend to live in extremely cold places, in order to adapt to the harsh climate, wood frogs have evolved the most special hibernation in the animal kingdom - their hearts have completely stopped beating when they hibernate, while the hibernation of other animals generally reduces the rate of heartbeat rather than stopping completely.
Special substances in wood frog cells cause wood frogs to stop biochemical activities when frozen and avoid breaking the cells.
<h1 class= "pgc-h-arrow-right" >1: Zebrafish – a heart that can regenerate</h1>
Zebrafish are native to the Himalayas and are now distributed to most of South and Southeast Asia. Zebrafish is a popular ornamental fish and an important model organism in scientific research. Zebrafish has an amazing regenerative ability, its heart, liver, kidneys and bones can regenerate, so it is often used in scientific research to study regenerative ability. This regenerative ability is extremely rare in higher vertebrates.