The crocodile, having heard this word, the facial expression of our face changes automatically. They scare us with their fierce and murderous activities. Crocodiles belong to the class “Reptile” of the phylum “Hordata”. The order to which they belong, the crocodile and the family - Crocodylidae. There are three members of the Crocodylidae family that are present today, and they include crocodiles, alligators, gharialas and caimans. These are large aquatic reptiles found in all the tropics, Asia, Africa, America and Australia. They develop well in rivers, lakes, wetlands, and sometimes in brackish water. They are carnivorous food for vertebrates, including fish, birds and mammals. Sometimes they also occur with mollusks and crustaceans. It is believed that they evolved 200 million years ago.
The word crocodile got its origin from the ancient Greek word crocodilos, which was used for lizards. Crocodiles are among the most complex reptiles that have a fully four-chamber heart and a well-developed cerebral cortex and a full diaphragm and muscles adapted for locomotion. External morphology is best suited for its aquatic lifestyle. The body is streamlined in shape, which allows it to quickly swim in water. They have webbed feet that are ideal for an aquatic lifestyle and reduce resistance during swimming. In crocodiles, the back of the mouth carries a palatal flap that injects water into the mouth when they are in the water. The nostrils close when they are under water. The corpus is bony and lacks sub-right and post-frontal bones. Their tongues are attached to the mouth with a thin membrane, so they cannot stick out the tongue.
The body is covered on the outside with scales that carry pores and are sensitive to function and are similar to the system of lateral lines in fish. The pores are mainly present in the upper and lower jaws. It is also believed that the scales secrete an oily substance that helps remove dirt. Crocodiles are left without food for a very short duration. They can hold the victim very tightly and grab it immediately. They have very strong and sharp teeth that easily penetrate the body of the victim. The muscles of the jaws are very strong. Crocodiles hunt for ambushes, and they wait for their victim to approach them, and when the victim approaches them, they will seize it with their strong jaws. They are cold-blooded and their metabolic rate is very slow, so they can remain without food for a longer time. Although they seem slow, they were also recorded by attacking sharks. It has been found that many crocodiles absorb stones, and these stones act as parts that help crush food, like a stomach in birds.
Salt glands also do not know that they are present on the surface of crocodile tongues, but they are completely absent in alligators. They are well developed in the hearing aid and are known to also create sounds when they become aggressive. Tympanine membranes are also present. Sometimes they also are known to consume smaller crocodiles. They are protected in many parts of the world and in some places are also sold for commercial purposes. Their skins are a source of leather for the manufacture of handbags, shoes, and they also account for most of the weakness in some countries. Commercially traded species include the Nile crocodile and crocodile. A crocodile hybrid with sea water, called the Siamese crocodile, is also produced on Asian farms.
Saltwater crocodile eggs are sold in different areas, and it has been desalinated to produce saltwater crocodile populations in Australia. They are usually thought to have evolved from dinosaurs and birds, so they are placed in the Archosauria group.
Crocodile embryos do not have sex chromosomes. Sex is affected by temperature. Males develop in the temperature range of 31.6 ° C, and females develop at somewhat lower and higher temperatures. The incubation period is an average of 80 days, but also depends on the temperature. Crocodiles can walk on the ground at a speed of about 17 km / h, as recorded in the Australian freshwater crocodile. Maximum speed of different species from species to species.
Crocodiles do not have salt glands, so they emit body heat through the mouth, and they often sleep with their mouths open. Body size varies from species to species. Large species can reach 4.85 meters weighing up to 1200 kilograms. They exhibit well-pronounced sexual dimorphism with males larger than females, and grow rapidly compared with females. Crocodiles start with a life span with an average size of only 20 cm and reach different sizes later. The largest species of crocodiles are marine crocodile species found in northern Australia and southeast Asia.
There is no specific method for determining the age of crocodiles. For this purpose, scientists use their predicted assumptions. Some believe that the lamellar growth rings present on bones and teeth help in detecting age. In addition to these inaccuracies, the average age of the oldest crocodile is 130 years. Crocodiles have smooth skin of the abdomen and sides, while the dorsal surface is rigidly characterized by the presence of bone osteoderm. Tough skin acts as a protective shell, and also undergoes excessive heat loss through the body.
Crocodiles are dangerous for people and, as you know, kill many people in different parts of the globe. Records of the human death of crocodiles are known in the UK and Burma. In addition to their menacing nature, they are also a source of economic value. Their skin is a source of leather for the manufacture of items of commercial importance, and they are also consumed in some countries as a favorite dish.
The conclusion is that we must love the crocodiles and save them from extinction.
