20 ANIMALS THAT CRAWL OR CRAWL AND THEIR CHARACTERISTICS - BIOLOGY - 2025

Among the animals that crawl to move around are the iguana, the snake, lizards and other animals belonging to the class of reptiles. It is not known exactly whether reptiles (reptilia) constitute a class of animals or a group. In any case, the living beings belonging to this classification have common characteristics, be it the aspect or the way in which they move.

Dinosaurs belonged to this group. Within this set, you can find animals of all sizes and from different habitats. In this article, you can learn more about some of them.

1- Iguana

Iguanas are herbivorous lizards with flabby skin on their throats and spines protruding from their heads, necks, backs, and tails. Iguanas can live 15-20 years.

The green iguana can be 1.5 to 2 meters long, while the spiny-tailed iguana grows 12.5 to 100 centimeters long. The heaviest iguana is the blue iguana, which can weigh up to 14 kilograms.

They are cold blooded. This means that the outside temperature is what keeps them warm, since they have no way of regulating the internal heat with their own bodies.

These lizards are found in Mexico, Central and South America, the Galapagos Islands, on some of the Caribbean islands, Fiji, and Madagascar.

2- Chameleon

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Of the family Chamaeleonidae, they are Old World lizards, mainly arboreal, known for their ability to change the color of their body.

Other characteristics of chameleons are zygodactilinear feet (toes fused into opposite bundles of two and three), acrodontate dentition (with teeth attached to the edge of the jaw).

Also very characteristic of chameleons are eyes that move independently, atrophied venom glands that produce harmless amounts of venom, and a long, thin tongue.

The specialized vision of these animals and the specialized projection system of its tongue allow it to capture insects and even birds from a distance.

Chameleon's eyes are very good at detecting and regulating light. The lens of a chameleon's eye is capable of concentrating extremely fast and can enlarge visual images as if it were a telephoto lens.

Chameleons can move their tongues at high speed over a distance of more than twice their body length and can strike and capture their prey with great precision.

The hydrostatic force resulting from the rapid contraction of a ringed accelerator muscle is used to project the tongue toward the chameleon's prey; a sticky tongue tip sticks to the victim's body.

3- Komodo Dragon

The Komodo dragon (Varanus komodoensis) is the largest extant species of lizard and belongs to the Varanidae family. It inhabits the island of Komodo and some neighboring islands of the smaller islands of Sunda in Indonesia.

Interest in the large size of the lizard and its predatory habits has allowed this endangered species to become an ecotourism attraction, which has promoted its protection.

The lizard is about 3 meters tall and weighs about 135 kg. It usually digs very deep burrows (about 30 feet) and lays eggs that hatch in April or May.

The newly hatched dragons, about 18 inches long, live in trees for several months.

Adult Komodo dragons eat smaller members of their own species and sometimes even other adults. They can run quickly and occasionally attack and kill humans.

They rarely need to capture live prey directly, as their venomous bite releases toxins that inhibit blood clotting.

Its victims are thought to go into shock from rapid blood loss. Some herpetologists point out that the physical trauma of the bite and the introduction of bacteria from the Komodo dragon's mouth into the wound kills the prey.

4- Giant tortoise of the Galapagos Islands

The giant tortoise is perhaps the most iconic species in the Galapagos. In fact, the name of Galapagos comes from the old Spanish word "saddle", referring to the shape of some shells of giant tortoise species.

Today, the giant tortoise has come to symbolize the uniqueness and fragility of life on the Galapagos Islands. Giant tortoises roamed much of the world before the arrival of Homo sapiens.

Today, they are only found in a few isolated island groups in the tropics, including the Galapagos archipelago, the Seychelles, and the Mascarene Islands.

These turtles can weigh up to 250 kilos. Scientists believe that the ancestors of the Galapagos tortoises arrived on the islands two to three million years ago from the mainland of South America.

Fourteen separate populations settled on ten of the largest islands. Today, taxonomists consider each island population a distinct species, although recent genetic studies suggest that there may be considerable differences between the populations found on the island.

5- Galapagos marine iguana

The marine iguana is another iconic species from the Galapagos. This endemic reptile is the only maritime lizard in the world and can be found on rocky shores in most of the archipelago.

The marine iguana has adapted to venture out to sea for food, a unique habit that gives it access to an abundant source of food throughout the year. Their diet is based on algae that grow on rocks and even small crustaceans.

Large males have been observed diving to depths of forty feet and staying underwater for up to an hour.

Among the many adaptations that allow the marine iguana to occupy this unique ecological niche, are a short, blunt nose, a long flattened tail that effortlessly propels them through the water, and a special gland that allows them to rid their bodies of excess salt that consume as part of their diets.

Perhaps its most remarkable adaptation, unique among all vertebrates in the animal kingdom, is the ability to actually shorten its body length during certain times, such as periods of famine caused by the El Niño phenomenon.

When food becomes abundant again, the marine iguana returns to its normal size. Researchers believe that to accomplish this miraculous feat of survival, marine iguanas literally suck up a portion of your bones.

6- Anaconda

Of the genus Eunectes, it is one of two species of constrictive and water-loving snakes found in tropical South America.

The green anaconda (Eunectes murinus), also called the giant anaconda, branchi, or water kamudi, is an olive-colored snake with alternating black spots that are oval in shape. The yellow, or southern anaconda (E. notaeus) is much smaller.

Green anacondas live along the tropical waters east of the Andes and on the Caribbean island of Trinidad. The green anaconda is the largest snake in the world. This anaconda can measure more than 10 meters.

7- Boa

Boa is the common name for a variety of non-venomous constrictive snakes. There are more than 40 species of boas (Boidae family).

In addition, the boa can also refer to two other groups of snakes: the Mascarenas, or and the dwarf boas (ground and wood boas of the Tropidophiidae family).

Members of the Boinae family range from 1 meter (3.3 feet) long in some species to more than 4 meters. Although these snakes rarely exceed 3.3 meters (11 feet) in length, some reach much more than 5 meters.

The boa occupies a variety of habitats from the coastal north of Mexico and the Lesser Antilles to Argentina. A subspecies, the red-tailed boa is particularly popular in the pet trade.

8- Cobra

Cobra is one of several highly venomous snake species, most of which expand their neck ribs to form a hood. Although the hood is characteristic of cobras, not all of them are closely related.

Cobras are found from southern Africa through South Asia to the islands of Southeast Asia. Different species are the favorites of snake charmers.

The venom of the cobra generally contains neurotoxins active against the nervous system of the prey, mainly small vertebrates and other snakes. Bites, particularly from larger species, can be fatal depending on the amount of venom injected.

Neurotoxins affect respiration and, although the antidote is effective, it must be administered soon after the bite. Thousands of deaths occur each year in South and Southeast Asia from cobra bites.

9- Viper

It belongs to the Viperidae family. It can be any of the more than 200 species of poisonous snakes belonging to two groups: pit vipers (subfamily Crotalinae) and Old World vipers (subfamily Viperinae), which are considered separate families by some authorities.

They eat small animals and hunt by beating and poisoning their prey. Vipers are characterized by a pair of long, hollow, venom-filled fangs attached to movable bones in the upper jaw (the maxillae), which fold back into the mouth when not in use.

Their eyes have vertical pupils. They are less than 25 cm (10 inches) long when it comes to the dwarf viper, while the Namaqua (Bitis schneideri) of southern Africa is more than 3 meters.

10- Skink

Of the Scincidae family, it is one of about 1,275 species of lizards. Skinks are secret inhabitants of the land or burrows, found throughout most of the world, but are especially diverse in Southeast Asia and its associated islands, the deserts of Australia, and the temperate regions of North America.

The largest species of skink reaches a maximum length of nearly 30 inches (76 cm), but most species are less than 8 inches (20 cm) long.

Some species of skink may have peculiarities such as reduced or absent limbs and sunken eardrums.

Some species are arboreal and others are semi-aquatic. Skinks often eat insects and small invertebrates. Large species are herbivorous and consume fruits of various kinds.

11- Two-Legged Worm Lizard

This species is endemic to the Baja California peninsula, Mexico and ranges from the extreme southwest of Baja California, through western Baja California Sur, to the Isthmus of La Paz and the western Cape region.

It is probably a relatively abundant species, but it is not often found. Scientist Papenfuss collected 2,719 specimens in an extensive study of the species that he conducted in 1982.

To live, this fossil species requires areas with sandy soils with abundant litter. They are rarely seen on the surface. The general habitat in its range is dry and desert, with serum tree vegetation.

These reptiles build an elaborate system of burrows just below the surface, usually centered on the supports of vegetation.

12- Leopard Tortoise

It is the largest species of tortoise in southern Africa. It is the only species in the genus Stigmochelys and is often kept as a domestic animal due to its ability to adapt to captivity, where such animals are easily raised.

When these turtles are transported from the Cape provinces to the northern parts of the country they mix with local populations as many escape or are released by the owners.

When genetic strains are mixed together, turtles lose their identity which scientists are really concerned about. There is also the danger of introducing disease into local populations. However, these can be killed because they are not resistant to pathogens.

Being relatively durable animals, they can reach an age of up to 100 years under normal conditions. In captivity they can live from 30 to 75 years.

13- Gecko

The gecko is any lizard in the Gekkonidae family, which consists of more than 100 genera and almost 1,000 species.

Geckos are mostly small, usually nocturnal reptiles with very soft skin. They also have a short, stocky body, a large head, and typically well-developed limbs.

Most species are between 3 and 15 cm in length, including the length of the tail. They have adapted to habitats ranging from deserts to jungles.

Currently, the gecko family is composed of five subfamilies: Aleuroscalabotinae, Diplodactylinae, Eublepharinae, Gekkoninae, and Teratoscincinae. Both Aleuroscalabotinae and Eublepharinae have movable eyelids.

14- Python

Pythons are non-poisonous snakes that can be found in Asia, Africa, and Australia. Because they are not native to North or South America, they are considered Old World snakes.

The word "Python" can refer to either the family Pythonidae or the genus Python, which is found within the Pythonidae. There are 41 species of pythons found within the Pythonidae family, according to the Reptiles database.

Most pythons are large snakes, they can grow over 30 feet (9 meters) long. There are also small species of pythons such as the ant python (Antaresia perthensis), which only grows 24 inches in length and is considered the smallest species of python in the world.

15- Phrynocephalus or Arabian agama

The p hrynocephalus arabicus is a member of the Agamidae family, also known as the chisel-toothed lizard. This name is because its fused and compressed teeth are firmly attached to the upper jaw, unlike most lizards that have loose teeth.

These animals are also known as Old World chameleons due to their amazing ability to change their body color. They typically have a broad, strong, flattened body and a long, flattened tail rounded at the base.

The Arabian toad-headed agama is a fairly small lizard that is highly adapted to life in the desert. It is highly variable in color with various patterns of black, white, and reddish markings, and it tends to match the color of its background.

The lizards found on the pale sands of the coast tend to be paler and less patterned than the red and white sand lizards.

16- Gila Monster

The Gila monster (Heloderma suspectum) was named so because it inhabits the Gila River basin. It is also found in Arizona, California, Nevada, Utah, and New Mexico, as well as the Mexican states of Sonora and Sinaloa.

It grows about 50 cm (20 inches). It is a robust reptile with black and pink spots or bands. It is the largest lizard in the United States.

During warm weather, the Gila monster feeds at night on small mammals, birds, and eggs. The fat stored in the tail and abdomen is used during the winter months.

Its large head and muscular jaws produce a strong bite that is held while venom seeps into the wound. Many of its teeth have two grooves that conduct venom.

17- spider tortoise

Its scientific name is Pyxis arachnoides. The Madagascar spider tortoise (Pyxis arachnoides spp.), Or Kapila, as this species is called locally, has a carapace size of around 15cm. This makes it one of the smallest tortoise species in the world.

With an intricate pattern that resembles the spider web on its shell, it is considered one of the most beautiful and charismatic turtles in the world. It feeds on insects, fresh leaves, and larvae. It lives for approximately 70 years and is in serious danger of extinction.

18- Tree crocodile

These crocodiles are found on the island of New Guinea. Most prefer the lowland environments of the island near the coast, although some have been observed living in mountainous environments up to 650 meters (around 2,100 feet) high.

They are mainly black in color, with green, yellow or white spots. These reptiles weigh up to 90 kg (almost 200 pounds).

Although Komodo dragons are larger in weight, tree crocodiles are longer, reaching up to 5 meters (approximately 16 feet) in length from snout to tail.

These reptiles are sometimes hunted for their meat and skin. They are known to be very aggressive, and therefore it is considered risky to hunt them. Therefore, to capture them, traps are used for other animals.

19- Angonoka Tortoise or Plow Turtles

They are small land turtles that are about 40 centimeters long. Males weigh just over 10 kilograms, while females about 8.8 kilograms - the sexes can often be visually distinguished by size.

One of the plates, or shields, of its lower shell projects outward and upward between the front legs, which vaguely resembles a plow, giving the species its name.

Turtles live on land and eat all kinds of plants. They eat dead bamboo leaves, they seem to avoid shoots and fresh leaves. They also eat the droppings of mammals that live in their area.

The female buries up to seven egg embryos per season, leaving her young to hatch at the beginning of the rainy season.

Sexual maturity is not achieved during the first two decades, an unfortunate trait for an animal highly threatened by danger of extinction.

20- blind shingles

Blind shingles inhabits the Iberian Peninsula and appears to differ genetically from those elsewhere, making it a separate species.

This species is endemic to this region of the world. It is found throughout Portugal and in most of central and southern Spain, especially in the Sierra Nevada.

It is difficult to determine the abundance of this species, but it seems to be more common in areas of sandy and moist soil. It is an underground reptile found in a wide variety of Mediterranean habitats. Females lay only one egg.

References

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