Frogs have been there on Earth since times immemorial and during the rainy season, they can be practically found all over the place. In fact, their mere presence is enough to announce the arrival of monsoons. Frogs have also been associated with humans and there are many tales and stories that have been there since long.
However, unlike human beings, frogs are not mammals rather they are amphibians meaning that they can live both on the land as well as in water, with equal ease. Frogs lay eggs in water so that small tadpoles are produced from it. During the initial period, they mostly spend their time in water after hatching out from the egg. Later on, they metamorphoses into adult frogs and this is when they venture out on land.
There are some particular peculiarities related to tadpoles in the sense that they resemble more closely to fish than a frog. During the initial days, they usually breathe using gills that are present in their body at that time and wear out as they start developing into a frog. In a similar way, the tails of tadpoles can be expected to be long finned, again pointing to a similarity to fishes.
Due to its initial years being spent much in moist surroundings, it is very essential that a frog must live close to a moist environment like a pond, swamp or a damp habitat. It is because its skin must be moist at all times and in no case should it go dry or else that may prove fatal for the creature. It is due of this reason that frogs can be found near to places that are wet and moist. Moreover, such places can also be helpful for them in finding their food.
One of the outstanding features of this animal is that in spite of staying in moist places, it never drinks water! Rather, the needed water is absorbed by them through their skin.
Apart from this, many other facts are also discussed in the following sections that can be helpful in getting a good idea regarding this animal. We shall look into them one by one.
Table of Contents
General Facts Regarding their Existence-
There is enough evidence to suggest that frogs have been there on Earth for more than 200 million years. It is roughly the same time for which dinosaurs may have been present!
Goliath frog that is found in Western Africa is considered to be the largest in size among all types of known frogs. It can be as long as 15 inches and the weight can be up to 7 pounds! Speaking of frog dimensions, it can also be mentioned here that the smallest known frog around the world is the Cuban Tree Toad, that can be only half of an inch in size.
As of frogs life expectancy, not much is known regarding the ones that live in the wild but there are some records to suggest that there are frogs in captivity that have managed to live well beyond 20 years.
Also, there are more than 6,000 known species of this animal that has already been discovered. Moreover, scientists and herpetologists worldwide are continuing with their search for newer variants from the family and these are continuously kept updated.
One more clarification regarding frogs is that toads are also from the frog family. The only major difference from a conventional frog is that these may have dry and warty skin and the hind legs may be comparatively smaller than a frog.
Physiological Facts Related to Frogs-
The physiology of the animal is in such a way that it can easily look and breathe even when maximum part of its body is underwater. It is possible due to the nose and eyes being over its head so that clear visibility can be maintained. Frogs can be quite sensitive to any type of movement. They are also well endowed with superb vision at night so that they can catch their prey in less light and at the same time can easily camouflage themselves.
It is also a fact that frogs tend to shed their skin once a week so that a new layer can be regrown. The old peeled off layer is usually consumed by them.
The bulging eyes of a frog enables it to see straight, sideways as well as somewhat behind it too so that it can maintain nice visibility all around it. They do not close their eyes even when they sleep. However, it is noteworthy to mention here that frog's eyes cannot see all color. They see everything around them in black and white only. The eyes also play an important part in the food digestion. As soon as it swallows food, it pulls its eyes towards the mouth roof so that the food can go easily down the throat.
Also, it is known fact that only the upper jaws of most frogs have teeth. Another peculiar feature in a frog is that its tongue is connected to the front of the mouth rather than the back. This is also a reason why it is able to stick its tongue out so long and farther than usual. The tongue of a frog can be quite muscular and sticky so that it is able to catch and consume its prey using it. They usually consume meat (bugs and worms) and are known to swallow the complete food at one go.
Most frogs have nostrils for purifying the air that they breathe but in 2008, herpetologists have found a variant in Indonesia that is practically lungless and it breathes through its skin. It is not uncommon to understand here that frogs can absorb half of the air needed by them through the skin.
It can be very easy to determine the gender of a frog. Scientists and zoologists generally believe that if the ear of a frog that is located behind its eyes are bigger than its eyes then it is male else female.
Finding the age of a frog can also be quite interesting. When a frog hibernates, frog bones are formed and a new ring appears every year. Counting these rings can help in determining the age of a frog successfully.
Frogs were perhaps the first land animals to have vocal cord in their throat for producing sound. Male frogs generally have the vocal sacs that are nothing but skin pouches having air inside them. When the animal croaks, it can produce sound that can resemble a megaphone. There are some varieties of frogs whose croaks can be heard at least from a mile away.
Mobility facts Related to Frogs-
It can be quite interesting to note here that there are some varieties of frogs that can leap over 20 times the size of their body length and that shows the enormous ability of this animal to jump around.
There is a typical Costa Rican variety of frog that roams around on trees from one branch to another using its feet. It is further helped by its web that is present between the fingers and its extending toes so that it can easily glide through different trees.
Some Camouflaging Ways Utilized by Frogs-
Frogs can be one of the most intelligent animals as far as camouflaging from their predator is concerned. They can hide themselves brilliantly in many sorts of different colors so that they easily blend with their surroundings and at the same time can be distinctly visible so that their attacker may know that they are available but may not attack them due to the fear of them being poisonous.
A glaring example is the Budgett frog, which is muddy brown color and that can be easily confused with a lump of mud. Similarly, Vietnamese Mossy frog displays bumps and spotty skin so that they resemble more like little bunches of lichen or moss. Poisonous frogs like the Golden Poison frog and the Dyeing Poison frog have boldly colored skins that is more of a warning signal to a predator. The skin of these frogs can itself be toxically fatal.
There are also some other varieties of frogs that have successfully mimicked some poisonous varieties of the species yet their skin may not be poisonous. A prime example of this type is the Fort Randolph Robber frog that has a skin coloring similar to another poisonous variety from the same family yet this one is not poisonous. Hence, it can sufficiently stay protected from a predator.
Golden Dart frog can be considered to be the most poisonous variety of frog that is known to mankind. A skin of this frog can be enough to kill at least thousand people!
However, some recent discoveries have also come up with utility features through frog's skin. For example, there is a particular variety of frog skin that can be 200 times more powerful than morphine as a painkiller and therefore it can have amazing usefulness in medical science.
The Survival Instincts of a Frog is Marvelous-
As already discussed, frogs are amphibians and that essentially means they are cold-blooded animals. It further implies that their temperature of the body changes as per the surrounding temperature. Hence, when ambient temperature goes down, they either dig burrows in mud or at the bottom of a pond and lay there completely still. This period of minimum mobility is called Hibernation and it continues till spring.
The Wood frog is known to display enough survival challenges as it can be found beyond the Arctic Circle. 65% body of this frog can remain frozen for weeks together yet it can easily survive the harsh weather. Actually, it has an internal mechanism through which its vital organs utilize the blood glucose as an anti-freeze so that these organs do not get damaged in the harsh weather whereas other body parts get completely frozen.
Another such example of survival is the Australian Water-Holding frog. This frog can withstand itself for seven years without rain. In extreme conditions, it digs an underground burrow and covers itself in a cocoon that is made up of its own skin. This way, it can easily sustain itself for a long time without any external help.
One more important fact regarding frog is that these are mostly freshwater creatures and are found near freshwater sources only. Although there are a few from the family that may be able to survive in brackish or salt waters too. A good example of such type is the Florida Leopard frog.
Mating and Tadpole Hatching Facts-
The mating and fertilization process in frogs is quite unique and unlike very few other creatures. There are some varieties of frogs that have capacity to lay up to 4,000 eggs at a time. Fertilization of frog's egg usually happens away from the body of the female. There is a mating hug that is known as Amplexus and it is found in the male's waist. It is this Amplexus in which the female lays its eggs and the male then fertilizes them accordingly.
The complete egg fertilization process of a frog depends on the type of frog and it may well last from a couple of hours to a few days. Research on some frogs have suggested that an Andean frog has remained in an Amplexus for around four months also and hence the period of fertilization can differ from one type to another.
The eggs are generally kept in a pouch just like kangaroo that secures its children in its pouch. When tadpoles get hatched from these eggs, the pouch is made open with the help of toes so that these get spilled into the water.
There is a very famous toad from the South American country of Suriname, Pipa Pipa. The peculiarity of this toad lies in the fact that the mother carries the young on her back, well into its skin, perfectly embedded. Post mating, the eggs start accumulating on her back and a new layer of skin gradually develops over it so that it gets perfectly concealed. Prior to hatching, the froglets can be seen in their pockets. Gradually, they start freeing themselves up by sticking their forelegs and head out and thereafter freeing themselves all around.
One more example of a typical fertilization process in frog can be cited from the Australian Gastric Brooding frog. The female of this family swallows the fertilized eggs so that the tadpoles stay safe in her stomach for at least two months after which they come out through her mouth, hopping out as small frogs. The gastric secretions do not take place during the brooding period or else the female might end up eating her own children!
Also, in Darwin frogs, the male of the family may swallow and keep the tadpoles there in the vocal sac till they start to come out as little frogs.
We have listed some quite interesting facts related to frogs and this information can be quite useful for people who are interested in this animal.