How Many Eyes Does a Tarantula Have?

There are over 1,000 species of tarantulas in the Theraphosidae family, with over 50 species inhabiting North America. Among these tarantula species, there are many variations in appearance, behaviors, and preferred habitats. Yet their basic biology is the same, including the number of eyes. So, how many eyes do tarantulas have? Read on to find out.

Tarantula Eyes

Tarantulas have eight eyes, like most other spiders. Their eyes are relatively small and are grouped closely together in two rows. They have one pair of eyes in the center of their head and three eyes on each side.

Tarantula Vision

With eight eyes, one would expect the tarantula to have excellent vision. However, this is not the case at all. Despite having many eyes, tarantulas have very poor vision. Although only certain cave-dwelling tarantula species are fully blind, most tarantulas have very limited vision.

The number and positioning of their eyes means they have nearly 360° vision. Yet each eye performs a different function and cannot see very far. They have simple eyes, or ocelli, which are single lenses lacking the elaborate retina found in most vertebrates. Unlike human eyes, which have a soft outer layer, tarantula eyes are covered by part of their exoskeleton. The hard exoskeleton does not allow the eyes to move freely, so tarantulas cannot track moving objects.

One could also compare the tarantula’s eyesight to that of a near-sighted human. Such a person could see shapes and motion, but might not easily recognize an object unless viewing it up close. Tarantulas can also detect movement and distinguish between light and darkness, but they cannot see clear images.

Can Tarantulas See in Color?

There has been a long-held belief that tarantulas cannot see in color. However, a recent study suggests this may not be true. Scientists have found that tarantulas have patterns of light-sensitive proteins called opsins that are typically only found in diurnal spiders with color vision. So crepuscular tarantulas that are most active at twilight may be able to see colors just as well as spiders that hunt during the day.

Using Their Other Senses

Tarantulas depend on their other senses to hunt, catch prey, navigate, and evade predators. They have thousands of hairs on their legs and bodies called setae. These hairs can detect the slightest movements and vibrations on the ground or in the air. The spiders can even use these vibrations to determine the size and location of their potential prey.

Tarantulas also have sensory hairs on their feet and around their mouths. These hairs allow them to chemically smell and taste their environment. The hairs can help them to recognize potential mates or determine if a possible meal is something edible. So, even though tarantulas have eight eyes, vision is relatively unimportant compared to their other senses. Tarantulas primarily depend on vibrations, touch, and taste to navigate their environments.