What Is the Difference between a Tarantula and a Spider?

The term "spider" broadly refers to any member of the order Araneae, a group that includes a stunning variety of over 45,000 species, ranging from tiny spiders to large tarantulas. Among these, tarantulas belong to a specific family known as Theraphosidae, making them a unique type of spider.

Tarantulas are distinguished by several key characteristics that set them apart from other spiders. One of the most notable traits is their size, as they are significantly larger than most spiders, with some species reaching up to 30 cm (12 inches) in leg span. Their robust bodies, often covered in hair, give them a distinctive furry appearance, while their thick, powerful legs aid them in both digging and hunting.

Unlike many spiders that rely on intricate webs to catch prey, tarantulas take a more active approach to hunting, using burrows or underground shelters as their base. Their solitary nature and tendency to become defensive when threatened further highlight their uniqueness, contrasting with other spiders that may live in groups or exhibit more passive behaviors.

So, while tarantulas are technically spiders, their unique traits and habits set them apart within the vast and diverse spider world.

Tarantulas, as mentioned earlier, possess several distinct physical characteristics that set them apart from other spider species. These traits reflect their adaptation to different ecological niches and lifestyles:

Size

One of the most notable differences is their size. While most common spiders measure between 1 and 2 cm (0.4 to 0.8 inches) in body length, tarantulas can exceed 10 cm (4 inches) in body length, with a leg span reaching up to 30 cm (12 inches). This significant size difference not only gives tarantulas a visually imposing appearance but also influences their hunting methods and defensive strategies.

While tarantulas are generally larger, some spiders, like the Giant Huntsman Spider (Heteropoda maxima), can reach impressive sizes. However, they tend to be lighter and not as massive as tarantulas.

Body structure

Tarantulas have robust, bulky bodies designed to support their larger size and weight. Their large, rounded abdomens are often covered with fine hairs that serve as a defense mechanism and help them detect environmental vibrations.

In contrast, many other spiders have thinner, more slender bodies, with smaller abdomens that come in various shapes, ranging from rounded to elongated.

Legs

Tarantulas' legs are much thicker and stronger than those of most spiders, enabling them to support their weight, dig burrows, and catch prey efficiently. These sturdy legs often have a spiny, rough texture.

On the other hand, many spiders have thinner, more delicate legs, optimized for building webs or moving quickly across surfaces, with smoother, less ornate structures.

Eyes

A key distinction between tarantulas and other spiders lies in the arrangement and size of their eyes.

Tarantulas generally possess large, prominent eyes that are crucial for their hunting habits. They have two forward-facing "principal eyes" that allow them to see in low-light conditions, along with six smaller secondary eyes that enhance peripheral vision and help detect movement in their surroundings.

In contrast, many other spiders exhibit a wider variety of eye arrangements depending on their behavior. While most have eight eyes, some species can have as few as six or as many as twelve. Their eyes are often grouped in clusters, with some facing forward for direct vision and others facing sideways to detect movement, especially in species that rely on web-building or ground hunting.

Body segmentation

Tarantulas display a clear and distinct separation between the abdomen and cephalothorax (the part that contains the head and thorax).

This abrupt transition is more noticeable compared to many other spiders, which often have smoother, more gradual transitions between these body parts, sometimes making the abdomen and cephalothorax appear almost fused together.

Want to understand what makes spiders so unique? Explore the different body parts and their functions in our comprehensive guide.

Tarantulas and other spiders also differ significantly in their behavior, ecology, and biology. These differences shape how they hunt, reproduce, and interact with their environments. Let us take a closer look:

Hunting strategies

Tarantulas are active hunters, relying on their size and strength to track down and capture prey, which often includes insects and even small vertebrates. They use their sturdy legs to immobilize and manipulate their victims.

In contrast, many spiders, such as orb-weavers or funnel-web spiders, rely on webs to catch prey. These webs can vary in shape—spiral, funnel-shaped, or tangled—and are designed to ensnare insects that get trapped in the sticky silk.

Habitat:

Tarantulas generally live in burrows or underground shelters, which they dig in the ground or find in protected spots like under rocks or logs. These shelters provide safety and a space to store prey.

Other spiders, especially those that rely on webs, typically live above ground, placing their webs in strategic locations such as corners, between leaves, or beneath rocks to capture passing prey.

Reproduction:

The reproduction and care of offspring differ between tarantulas and other spiders. Tarantulas often engage in complex courtship rituals before mating. Afterward, the female lays her eggs in a silken pouch, which she carefully guards. The young stay with the mother for a period before dispersing.

In contrast, many spiders lay eggs in a silk pouch and leave them unattended. The spiderlings are usually independent soon after hatching, with little or no maternal care.

Venom:

Tarantulas typically have venom that is less toxic to humans compared to some more venomous spiders, such as black widow spiders (Latrodectus spp.).

While tarantula bites can cause pain and swelling, they are not usually dangerous to humans. Additionally, tarantulas possess urticating hairs on their abdomen, which they can flick to deter predators. Tarantulas generally have larger and more robust fangs, which enables them to deliver their venom more effectively. Their fangs are typically thicker and more curved, a characteristic that sets them apart from the often slender fangs of other spiders.

On the other hand, venomous spiders like those in the family Theridiidae can deliver bites that are more dangerous to humans due to the potency of their venom.

Lifespan:

Tarantulas tend to have much longer lifespans than many other spiders. In captivity, they can live between 10 and 30 years, while in the wild, their lifespan typically ranges from 5 to 20 years, depending on the species.

Tarantulas are slow-growing and undergo multiple molting stages throughout their lives. In contrast, many common spiders have shorter lifespans, often living less than a year, with fewer molts and faster life cycles.

Curious about the incredible way spiders perceive their environment? Learn more about their unique eye structures in our in-depth guide.

If you want to read similar articles to What Is the Difference between a Tarantula and a Spider?, we recommend you visit our Facts about the animal kingdom category.