Category Zoology

While many fish swim in shoals, eating plankton as they flash through the water, others spend most of their time on the ocean bed. As the fish evolved, their eyes developed on the same side, so that both can see into the water above.

These quick-change artists have eyes on top of their heads, yet marvelously mimic the surfaces they sit on. This prompted Clayton Louis Ferrara to ask Weird Animal. Flatfish have eyes on the top of their heads, how do they see what’s going on the ocean floor?”

Flatfish, found all over the world, range from the angler fin whiff which is about three inches (eight centimeters) to the Pacific halibut, which can get up to around nine feet (three meters) long. This fish group includes species familiar to seafood lovers—not only halibut, but flounder, sole, and turbot.

All flatfish have eyes on the end of stalks, so they pop out of the head “kind of like the eyes we saw in cartoons—ba-boing!” 

Flatfish eyes can also move independently, widening their field of vision. Once flatfish eyes get the lay of the land, they message the brain, which in turn sends signals back to the skin. This organ contains color-changing cells such as melanophores, which either expand or contract according to the background the fish is trying to match.

For instance, expanding their cells would make their color darker. All this neurological relaying is “a pretty sophisticated thing to do,” Burgess says—not to mention it takes flatfish between two and eight minutes to blend in.

Even more impressive than how the eyes work is how they get on top of the head in the first place. Flatfishes don’t start out flat. They start out looking like regular fish, kind of diamond shaped, and “as larvae, the eyes are in regular position on each side,” As they develop “the eye begins to migrate, moving over the top of the head, eventually settling on one side or the other”. This also requires the bones in their heads to move.

The flatfish’s bones are pretty pliable at this point, like the soft spot on an infant’s skull, so “as the eye moves, the bones in the head warp in that direction,” An additional bone, found only in flatfish, develops right under the migrating eye, giving them that goofy asymmetrical look.

          The cheetah (Acinonyx jubatus) can reach 105km/h (68mph) when sprinting over a short distance. For animals, fast speed often means survival. It means outrunning predators or catching prey. In order to be fast, every physiological characteristic is important. The ratio of height and weight, flexibility, and respiratory functioning are all things that affect speed. This article identifies the fastest mammals in the world and what makes them so fast.

          The cheetah is the fastest mammal on earth and can reach speeds of 68 to 75 miles per hour (mph). Though not the best for endurance, they run in short burst of 60 seconds or so. This feline is built for speed. They have large nasal passages that lead to large lungs, even the heart is enlarged to allow for maximum oxygen in the blood. Cheetahs use their tail for balance and spend more time with their paws in the air than on the ground while running.

          The second fastest mammal on earth never runs on the ground. The Free-tailed bat soars through the nighttime air at 60 mph and it is their “free” or unattached tail that allows them to reach such speeds. They inhabit every continent except Antarctica.

          After the Free-tailed bat is the Pronghorn, a graceful antelope that reaches speeds of up to 55 mph. While this antelope cannot outrun a cheetah in a head to head race, it can run for longer periods of time. That makes this mammal the fastest over long distances and the fastest in the Western Hemisphere. They are native to North America and live in wide, open grasslands. Scientists believe the Pronghorn evolved such high speeds to outrun predators. They share some of the same physical features as the cheetah: enlarged nasal passages, lungs, and heart.

          Sharing the number 3 spot on the list of the fastest mammals is the Springbok, an African antelope. This animal reaches the same speeds as the Pronghorn, 55 mph, though it cannot sustain over long distances.

          Number 4 on the list is the Wildebeest, another species of antelope. These mammals run up to speeds of 50 mph which allows them to escape lions, hyenas, cheetahs and leopards. Although more than their speed, it is their herding behavior that helps protect them from predators. Every year, wildebeests make a long migration following the pattern of rainy and dry seasons.

          Most mammal babies develop inside their mothers until they are ready to be born. The exceptions are the monotremes, a small group of mammals found in Australia. Like most reptiles, they lay eggs rather than giving birth to live young. Perhaps the best known of these is the duck-billed platypus.

          Of course, the platypus isn’t really a mixture of these other creatures. It just looks like it! The platypus is a semi-aquatic mammal native to Australia (including Tasmania) and Papua New Guinea.

          Along with four species of echidna (a mammal that looks a bit like a porcupine), the platypus is one of only five species of monotremes in the world. Monotremes are mammals that lay eggs instead of giving birth to live young.

          The platypus has a bill like a duck, a tail like a beaver, the skin and feet of an otter, and venom like a snake. These features truly make the platypus one of the most unique creatures on Earth. In fact, when the platypus was first discovered hundreds of years ago, scientists at the time thought it was an elaborate hoax.

          The name “platypus” comes from the Greek word for “flat-footed.” The male platypus has special spurs on its hind feet that it can use to defend itself by injecting painful venom into a predator. Although the venom isn’t deadly to humans, it can cause severe pain.

          The platypus can walk and run on land, but it moves awkwardly. Its webbed feet and waterproof skin help it to live much of the time in the water, where it feeds on insects, shellfish, worms, and other small creatures at the bottom of bodies of water.

          The platypus is mostly nocturnal and can spend up to 10 hours at a time in the water, searching for food. When it’s done swimming, the platypus likes to live in a burrow dug into the bank of a nearby body of water.

          The female platypus lays one or two eggs each season. When a baby platypus emerges from its shell, it’s about the size of a lima bean. Its mother will take care of it for three months or so until it’s ready to head out into the world on its own.

Picture Credit : Google

          Almost all mammal babies grow inside their mother until they are able to breathe and feed outside, but mammal babies differ very much in the kind of help they need after birth. Human babies, for example, need the attention of their parents for many years before they are able to fend for themselves completely. Most grazing animals, on the other hand, have adapted to life on wide, open grasslands, where they are constantly at risk from attack by predators. It is important that these animals give birth to young that can stand on their own feet and run from danger almost immediately.

          Spring is the perfect time for baby animals to be born! Many animals have babies in the spring since the warmer weather makes it is easier for them to find food to feed them. Warmer weather also makes it easier for small babies to survive. Polar bears, which live in climates that are always very cold, actually have their babies during the winter while they are hibernating. When spring comes and warms things up a little, a mother bear will bring her cubs out of their cozy den for the first time and teach them how to find food for themselves. Other kinds of bears and some other large mammals also have babies during the winter, since they can nurse their babies and not have to leave their den to find food.

          There are lots of different kinds of animals living on earth. That means that there lots of very different kinds of baby animals! Even though we usually think of babies as being small and helpless when they are first born, that isn’t true for all animals. Some animals are very large even when they’re first born. Sometimes even the smallest ones are able to live on their own without any help from their parents when they are born. Keep reading to learn about some different kinds of animals and different ways that their babies are born and cared for.

          Mammals are animals that have hair or fur, are warm-blooded, and feed their babies with milk. Mammals give live birth, meaning that their babies are born from the mother’s body instead of hatching from an egg. However, there are two animals that lay eggs but are still considered mammals! They are echidnas and platypuses. Humans, elephants, cats, mice, pigs, rhinoceroses, gorillas, and many other animals are all mammals. Some are huge and some are tiny.

          Marsupials such as kangaroos, koalas, wombats, and opossums are mammals, too! When baby marsupials are born, they are very tiny and not as well developed as other mammal babies. They live in a fur-lined pouch on the outside of their mother’s belly where they nurse (drink milk) and stay safe and warm until they are big enough to come out. Even after the babies can come out of their mother’s pouch, they will still ride around on her back while they grow and learn how to survive on their own. Marsupial babies are called joeys. Almost all marsupials are nocturnal, which means they are awake at night and sleep during the day. Australia is home to most kinds of marsupials, but opossums do live in other parts of the world. In fact, the only marsupial that lives in North America is the Virginia Opossum, which can have up to 13 babies at once!

          Reptiles are cold-blooded, have backbones, have skin covered with scales, have claws on their feet, and baby reptiles’ hatch from eggs. A few kinds of snakes and lizards give live birth to their babies, but most lay eggs. Reptiles are born looking like smaller versions of their parents and are on their own almost as soon as they hatch. Their parents do not stay around to take care of them, because they aren’t really needed.

Picture Credit : Google

          Warm-blooded animals are able to control their internal temperature to a greater degree than cold-blooded animals, so that they are less dependent on the temperature of their surroundings. While reptiles slow down when the weather is cold, mammals are able to lead an active life. Mammals have adapted to life in all parts of the world where there is food for them to eat.

          Warm-blooded creatures, like mammals and birds, try to keep the inside of their bodies at a constant temperature. They do this by generating their own heat when they are in a cooler environment, and by cooling themselves when they are in a hotter environment. To generate heat, warm-blooded animals convert the food that they eat into energy. They have to eat a lot of food, compared with cold-blooded animals, to maintain a constant body temperature. Only a small amount of the food that a warm-blooded animal eats is converted into body mass. The rest is used to fuel a constant body temperature.

          Cold-blooded creatures take on the temperature of their surroundings. They are hot when their environment is hot and cold when their environment is cold. In hot environments, cold-blooded animals can have blood that is much warmer than warm-blooded animals. Cold-blooded animals are much more active in warm environments and are very sluggish in cold environments. This is because their muscle activity depends on chemical reactions which run quickly when it is hot and slowly when it is cold. A cold-blooded animal can convert much more of its food into body mass compared with a warm-blooded animal.

          To stay cool, warm-blooded animals sweat or pant to loose heat by water evaporation. They can also cool off by moving into a shaded area or by getting wet. Only mammals can sweat. Primates, such as humans, apes and monkey, have sweat glands all over their bodies. Dogs and cats have sweat glands only on their feet. Whales are mammals that have no sweat glands, but then since they live in the water, they don’t really need them. Large mammals can have difficulty cooling down if they get overheated. This is why elephants, for example, have large, thin ears which loose heat quickly. Mammals have hair, fur or blubber, and birds have feathers to help keep them warm. Many mammals have thick coats of fur which keep them warm in winter. They shed much of this fur in the summer to help them cool off and maintain their body temperature. Warm-blooded animals can also shiver to generate more heat when they get too cold. Some warm-blooded animals, especially birds, migrate from colder to warmer regions in the winter.

Picture Credit : Google

          Most birds can fly, but there are also some flightless species. These all have other ways of escaping from predators. The larger flightless birds, such as ostriches and emus, can run very fast. Penguins cannot fly but can swim and dive at great speed, using their wings as flippers to power them through the water.

          Most birds fly. They are only incapable of flight during short periods while they molt, or naturally shed their old feathers for new ones. There are, however, several birds that do not fly, including the African ostrich, the South American rhea, and the emu, kiwi, and cassowary of Australia. The penguins of the Southern Hemisphere are also incapable of air flight. They have feathers and insulation for breeding purposes, but use a different form of motion: their sleek bodies “fly” through the ocean using flipper-like wings. All of these flightless birds have wings, but over millions of years of evolution they have lost the ability to fly, even though they probably descended from flying birds. These species may have lost their ability to fly through the gradual disuse of their wings. Perhaps they became isolated on oceanic islands and had no predators; therefore, they had no need to fly and escape danger. Another possibility is that food became plentiful, eliminating the need to fly long distances in search of food.

          No list of flightless birds would be complete without the penguin. All 18 species of penguin are unable to fly, and are in fact better built for swimming and diving, which they spend the majority of their time doing. Their short legs and stocky build give them a distinctive waddling walk. While people tend to associate penguins with Antarctica, most species live in higher latitudes. A few even live in temperate climates, and the Galapagos penguin actually lives at the Equator. These birds are also remarkably romantic—penguins are largely monogamous and seek out the same mates each season, even among the hundreds or even thousands of birds that might live in their colony.

          Three out of four species of steamer duck are flightless, but four out of four species should not be messed with. Even within the flighted species, some males are too heavy to actually achieve liftoff. These South American ducks earned their name by running across water and thrashing their wings like the wheels on a steamboat. They use them for other forms of thrashing, too. Famously aggressive, steamer ducks are known to engage in epic, bloody battles with each other over territory disputes. They have even been known to kill waterbirds several times their size.

          The Weka is another bird of New Zealand. This brown, chicken-sized bird was an important resource for native New Zealanders and European settlers, but is now decreasing in number. While they may look unremarkable, weka have a loud call that males and females sing as a duet. They’re also known as clever thieves and will steal food and small objects to their liking and make off with them. Weka are skilled swimmers, too.

          The kakapo, also known as an “owl parrot” is also a native of New Zealand. This nocturnal parrot has an owl’s face, penguin’s stance, and duck’s gait. It is truly a strange bird—but also a beautiful one, with bright green-brown feathers. It can grow up to 2 feet in length, and is the world’s heaviest parrot. The males make a distinctive booming call that sounds like a one-bird jug band, which can be heard up to half a mile away!

          The cassowary is a bird you don’t want to mess with. This giant bird, a native of Australia and the surrounding islands, is in the heavyweight class. The only bird heavier is the ostrich. As if that isn’t enough, the cassowary sports a wicked daggerlike claw that can grow up to 4 inches long on the middle toe of each foot —and they’ve been known to kill humans. If deadly power isn’t your thing, though, you can still admire the cassowary’s style. These birds sport colorful helmets, or casques, made of keratin (like human fingernails). And their plush back feathers kind of look like glamorous fur capes.

Picture Credit : Google