At a glance, there may not seem to be much of a difference between alligator and crocodile whereas the reality is that both these reptiles are quite unique and although they come from the same family yet there are quite a few differences between them. However, both the reptiles belong to the Crocodilia order and are largely predatory. Aquatic reptiles are found throughout the tropical lands of Asia, Africa, America and Australia. Crocodilia is the closest relative to birds and these two groups are the only living survivors of Archosauria. They have lived on the planet for more than 80 million years and can be said to be one of the oldest creatures of the planet.
Table of Contents
Characteristics of Crocodilia
Alligator, and crocodiles together form the order Crocodilia and are some of the most powerful creatures in this world. They are usually found in humid and swampy weather because they are reptiles and are, cold-blooded in nature. They usually prefer warm weather for living and therefore, this type of weather condition is suitable for them.
Their robust, long, thick tails and webbed feet are very much useful for them to live in water as well as on land. At the same time, their tough, durable skin is very helpful for them in thwarting any enemy attack. The webbed feet and tail help them to swim efficiently and without making any noise. They have a very developed a certain sense of smell and hearing. These are some of the outstanding features of this order and they help them to catch their prey.
As of a Crocodilians diet, it can absolutely consume anything. It can gorge on fish, turtles, rodents, birds, animals, crustacea and many other types of creatures. To some extent, these are also cannibals in the sense that they hunt down within their own species too when the size of a hunter is larger than the hunted!
The teeth of crocodiles grow throughout their lives. As one can see, they have a plier-like arrangement of teeth that can be very effective in tearing its prey to pieces. Therefore, it is important that these are kept in a proper way. Hence, they have the ability to shed their teeth and regrow them at the place where they lost it! This way, it can be quite beneficial for them to keep their set of teeth intact and that helps them in catching their prey and gorging on it.
As already mentioned, Crocodilians are cold-blooded animals that like to spend most of its time within water but then, when it comes to laying its eggs, these animals prefer to lay them on the land near to the water bodies where they live. They usually dig nests to keep their eggs secured near to the water source where they stay. They have a capacity of laying up to 50 eggs at a time but then most of these eggs do not hatch or fail to mature. On top of this, there is always a threat of these eggs being eaten by other animals. After hatching too, the baby crocodilians may not be able to make it in water easily as there may be predators all around them. Therefore, only a small number actually makes it to the water body in the future. In this way, it is quite a struggle to stay alive during the initial years and ultimately, make it to the parent's water source.
Catching Prey and Eating Features
One of the most outstanding features of alligator and crocodile is their capability of catching and eating their prey. It is one of the characteristics of this order that makes it quite phenomenal. These reptiles have some of the strongest and largest sets of jaws on the planet for any animal and therefore coming out of its grip can be impossible.
Both these reptiles have the added benefit of remaining underwater and yet breathe and see easily. This is due to the fact that their nostrils and eyes are located on top of the head and that helps it immensely. They can swim underwater and deftly make way through grassy waters as well without making any noise in spite of their huge bodies. This is a reason why they are able to move very near to their prey and then make the ultimate move of catching them. More often than not, once a prey has been caught by them, they try to pull it under water so that it can be drowned easily and the meal can be finished off there.
Behavior and Biology
Although there is a difference between alligator and crocodile yet the Crocodilia order is very much related to dinosaurs and birds. In spite of its prehistoric looks, crocodiles are quite complex reptiles. Crocodiles have a four-chambered heart and a cerebral cortex. They also have muscles that can be used for locomotion in water and can be compared to a diaphragm that is used for respiration.
There are salt glands in the tongues of crocodiles with pore openings on the tongue surface. This trait is clearly different from an alligator and one of the differences between alligator and crocodile. In alligators, the salt glands are not functional. Functionally, the salt glands are more like that of marine turtles. Also, they do not have sweat glands and seem to get rid of excess heat through the mouth. This is also the reason why crocodiles sleep with their mouth open at times and pant like dogs. They like basking in the sun and some of their species can even climb trees so that where there is a receding shoreline, they can easily climb atop trees and bask in the sun.
Crocodiles have Developed Senses
Crocodiles are said to be one of the smartest animals on the planet due to their sensing capability. This is the reason why they are very active predators and this sensory evolution is clearly an advantage for them. The four senses of vision, smell, hearing, and touch are quite well-developed in the reptile so that it is able to catch its prey with the least effort.
* Its Vision is Highly Developed
-Crocodiles are nocturnal animals due to which they have a very good night vision. This is where they score heavily on their prey who may not be able to see more clearly at night. Light receptors of their eyes consist of cones and rods due to which they are able to see and distinguish between colors. The pupil of their eyes has a vertical aperture, very similar to a domestic cat. The vertical pupil can be very useful in leaving out light more effectively so that eyes can be kept protected during the daytime.
The back wall of its eye has tapetumlucidum. It helps to reflect the incoming light on the retina thus helping with a small amount of light at night to be of significant importance. Things can be seen in a very clear way due to this even during the night time. They also have a nictitating membrane for protecting lower and upper eyelids. It is further helpful for covering the eye from the inner corner while eyelids are completely open. This is also the reason why the animal is able to see underwater and yet its eyeball surface remains secured from the water.
* Its Olfactory Senses Are Well developed
- Sense of smell in crocodiles is very much developed. It can smell carcasses or detect its prey from quite a distance. The chemoreceptors of crocodiles are particularly highly efficient because they are able to find their prey both on land as well as in water. There is only one olfactory chamber in crocodiles using which the olfactory system processes all sense perceptions of the animal. It has been widely experimented and proved that the animal can recognize both water-soluble and air-borne chemicals and use them for its hunting purposes. Volatile odorants are detected by the reptile above water through gular pumping which is a type of movement of the pharynx floor. When the animal is underwater, it closes its nostrils and hence it is unlikely that smell is perceived by it at that time rather taste and touch is made use of at that time.
*Their Hearing Sense is Superb
-Crocodiles have typanic membranes for hearing that is covered by flat flaps and may be raised or lowered using muscles.
Caudal - The lower and upper jaws have sensory pits that look like small black spots on the skin just like the lateral lines of fish and many other amphibians although the source of origin is very different than them. The pigmented nodules have nerve fiber bundles under it. These nerve bundles are responsible for catching any slight disturbance of water on the surface and detect pressure changes and vibrations to the tune of a single drop. These sensory organs are known as Domed Pressure Receptors (DPRs) and it helps crocodiles to detect any type of prey, danger or predator in complete darkness too.
Post-Caudal -Crocodiles have DPRs throughout its body. These receptors get flattened under excess osmotic pressure like that while swimming in the sea. When contact between its surface and sea water gets blocked, they may not be able to discriminate between salinities. However, it's function is not very well known and it is still a subject of study.
Differences Between Alligator and Crocodiles
Whereas alligator and crocodile belong to different biological families, these two names continue to be used interchangeably. Although there are many similarities between them yet they are quite different in appearance as well as behavior. Therefore, it is important to understand the differences so that both these reptiles can be better understood. We highlight here some of the key differences between them.
* Snout shape is different
- The snout shape of alligator and crocodile is quite different than each other and is also quite distinct. While a crocodile's snout is more pointed, narrow, longer and 'V' shaped, an alligator's snout is more wide, broad and 'U' shaped. This is, in fact, one of the most outstanding differences between the two reptiles and just by looking at them, it can be found out whether the reptile is an alligator or a crocodile.
The difference in snout shape may be due to the dietary preferences between the two. Crocodiles like to hunt upon fish, reptiles, and mammals whereas alligators are more inclined towards breaking turtle shells open. Due to this preference in diet, their evolution may have been likewise and hence the snout shape.
* Location Preference Between Them
- Crocodiles can be found in Africa, Southeast Asia, South America, Australia, North and Central America whereas alligators can be found only in eastern China and the southeastern US.
Within the US, there is a far greater chance of sighting an alligator compared to a crocodile because alligators are present within the country in large numbers. An exclusive American species of crocodile is found in the US that is present at the southernmost point of Florida but apart from it, there are alligators all around. Alligators can be easily sighted in Louisiana and Florida as well as in many parts of Alabama, North and South Carolina, Oklahoma, Georgia, Mississippi, Texas, and Arkansas.
Population wise too, alligators are far more in number compared to crocodiles. There are less than 2,000 crocodiles in the US whereas alligators are in excess of 3 million! This figure, in itself, makes it evident that sighting an alligator within the country can be very easy as compared to a crocodile. An interesting fact here is that Southern Florida is perhaps the only place on the planet where a person may see an alligator and crocodile living together!
* Their Habitat Preference is Different
- Alligators like to stay in freshwater or may sometimes be found in brackish waters. In contrast, crocodiles like staying in salty water most often and that explains the reason why crocodiles can be easily found along the Caribbean islands and not alligators.
As discussed above, it is due to the reason that crocodiles have salt glands on its tongue; it is able to excrete excess salt from the body. This is the reason why it is capable of spending days and weeks comfortably in the sea. Like crocodiles, alligators also have these glands but they do not work very well with them and that is why they mainly stay in freshwater or a mixture of freshwater and saltwater habitats.
* The Teeth Formation is Different
- One of the notable difference between alligator and crocodile is the way their teeth are formed. When both these reptiles’ mouths are closed, it can be very easy to identify through the snout as well as their teeth. An alligator's lower teeth will not be visible in such a condition whereas the lower fourth tooth will always be visible of a crocodile. The lower teeth of a crocodile will always protrude out from its lips forming a "jagged" smile whereas, in case of an alligator, its wide upper jaws can completely cover the lower one. Thus, no teeth may be visible from an alligator's lower jaws when its mouth is closed.
* Size-wise too, there is a Difference
- In terms of size also, there is a clear-cut demarcation between the two. Crocodiles can be much bigger compared to alligators and merely by looking at them, this can be understood. A full-grown adult crocodile can be up to 19 feet in length whereas an alligator can be maximum 14 feet long. This is a distinct difference between both of these reptiles.
* There is a Clear Color Contrast
- Crocodiles hides are lighter in color than an alligator's. Crocodile hide tends to be olive or light tan colored while an alligator's hide may seem to be more dark blackish with a tinge of grey on it.
Actually, the water in which an alligator stays is responsible for its hide color. Overhanging trees may have tannic acid in them and that can help in making it darker while the presence of algae can turn it to green.
* The Mobility Speed is Different
- Both on land as well as in water, an alligator can be faster than a crocodile. But there is a catch - both these animals may be quite slow on the land compared to water. They can "sprint" or "gallop" for short distances on land and that too, only when they feel threatened. Otherwise, there is hardly any brisk movement while they are on land.
On land, an alligator can move at a maximum speed of 11 miles per hour or 18 kilometers per hour while a crocodile may reach only about 9 miles per hour or 14 kilometers per hour.
However, in water, this figure can be better for both of them. This is due to the fact that their extended muscular tail can help them along with the webbed feet in swimming easily. The maximum speed of a crocodile in water can be 9 miles per hour or 15 kilometers per hour whereas the equivalent figure for an alligator may be a whopping 20 miles per hour or 32 kilometers per hour.
Conclusion
An alligator and crocodile can easily be recognized and identified by keeping these small points in mind. However, it is important to ensure that a person does not venture too close to them and should always maintain a distance. There are experts for handling these reptiles and in case if there is any query regarding these creatures, it is always better to ask the experts rather than moving too close to them to find an answer on one's own.