Frogs Frogs are amphibians in the order Anura. The order Anura is broken down into twenty-two different families of . Although they belong to the same order, frogs and toads are different in a lot of ways. Some of the more distinct differences are their skin and where they live.
Frogs usually have smooth, moist skin, and toads usually have dry, warty-looking skin. Frogs spend most of their lives in or near water, and toads spend more time on land. Amphibian means double life. Frogs and toads each have two parts to their lives: when they live on water and when they live on land. A frogs life starts in the water when it is hatched from an egg as a tadpole. A tadpole looks very different from an adult frog.
A tadpole has a tail, no limbs, and breathes through gills. After a while, the tadpole goes through a metamorphosis. During the metamorphosis, the frog grows limbs, the tail disappears, it uses lungs to breathe, and it doesnt have to live in water anymore. As a tadpole, the frog feeds mostly on vegetation. The tadpoles has a small rasping mouth suited especially for scraping algae from the bottom of ponds.
Depending on the species, it can take a few weeks to a year or more for the tadpoles to become fully grown. Not all frogs hatch as tadpoles though. Some species of frogs hatch as froglets. Froglets look just like adult frogs, but a lot smaller. Froglets dont go through a metamorphosis. Most species that hatch as froglets are found in dry places.
Frogs who live in dry places where rains are seasonal have to grow up quickly because a tadpole will die if their temporary pond dries up. Adult frogs can live in water or on land, but it always needs to be near water so that its respiratory organs dont dry out. Frogs also need to be near water because most species of frog lay their eggs in the water. In most species, only male frogs croak. They croak to attract female frogs, to display distress, and to warn away other male frogs from their territory.
Frogs reproduce by amplexus. During amplexus, the male frog holds on to the females back with specially adapted thumbs. Amplexus stimulates the female to release eggs that the male then fertilizes. Not all of the eggs that are fertilized will end up hatching though because they are not protected from predators and they are soft and can be easily damaged. The only defense the eggs have is a jellylike coating that has a bad taste.
Depending on the species, the fertilized eggs will take two days to a month to hatch. Most frogs live for about four to fifteen years. Frogs eat a variety of foods when they are full grown. Mostly, adult frogs are carnivorous.
They typically worms, spiders, centipedes, and other insects. Frogs have a tongue different from most animals. A frogs tongue is attached in the front and is sticky. These differences give the frog an advantage when trying to catch its food. Aquatic frogs also eat other frogs, small fish, and tadpoles. Some of the larger species, like the African bullfrog, try to eat almost anything, including other frogs, mice, small snakes, and small fish.
There are also a lot of animals that prey on frogs including alligators, snakes, owls, raccoons, and herons. Frogs have a few ways of defense. One of the most obvious ways is camouflage. The dorsal side of the frogs body is usually brown or green in color so it will blend with the ground when seeing it from above. The ventral side of the frogs body is light colored so that it blends with the sky when its swimming. The coloring of poisonous frogs acts as a warning sign.
Poisonous frogs are very brightly colored so that a predator will know it isnt safe to eat. Another way of defense for frogs is jumping. Their powerful back legs let them escape quickly. Some frogs can jump up to twenty times their own body length in one leap. Frogs often jump into ponds where they can hide underwater from their predators. On land, frogs jump in random directions to confuse the predator.
A frog also has to protect itself from the climate because, like all amphibians, they are cold-blooded. During the winter, frogs survive by burying themselves in mud and hibernating. Their body functions slow down so they dont need much energy. When hibernating in mud, frogs get air by absorbing it with their skin. There are many characteristics unique to frogs. Some external features are the bulging eyes and nostrils, the smooth, moist skin, external eardrums, and long back legs.
Frogs nostrils and eyes are specially designed so they see above water and breathe while they are floating near the surface. Each eye is also covered by a nictitating membrane. The nictitating membrane acts as a third eyelid and keeps the eyeball moistened. The smooth, moist skin helps them from drying out. On the frogs skin there are mucus glands that keep the frogs skin damp by secreting a slimy substance. Some frogs also secrete poison through their skin.
Frogs no real external ears. Instead, they have external eardrums called tympanic membranes. There is a tympanic membrane located behind each eye. A canal leading from the mouth to the tympanic membrane called the Eustachian tube keeps equal air pressure on each side of the tympanic membrane. The inner ear is located under the tympanic membrane. Frogs have long, muscular hind legs built especially for jumping and swimming.
Since jumping is a way of defense, there needs to be a lot of strength in their legs. Swimming also requires strong legs, and because frogs spend a lot of time in the water, the strength is necessary. Other characteristics unique to frogs are mouth breathing and a three chambered heart. To breathe through its mouth, the frog must first create a vacuum.
It does that by lowering the bottom of its shut mouth. Air moves into the mouth through the nostrils, then the frog closes its nostrils and raises its mouth. This forces air into the lungs. The three chambers of a frogs heart are two atria and one ventricle. Blood coming from the frogs body goes into the right atrium and blood coming from the lungs goes into the left atrium. The oxygen-poor and the oxygen-rich blood both go to the single ventricle where they mix and are sent to both the body and the lungs.
People have many uses for frogs. Frogs are used are used in education and medicine for research and learning. They are also important in controlling insect pests. Frogs feed on many species of insects, which greatly helps improve the quality of farm crops and helps defend certain plant species. 312.