You must have seen a macro photograph of spider eyes. They are fascinating to some and some people find them scary. Everyone reacts differently to the appearance of spiders. Many people think spiders are blind, but spiders are not blind. So, how do spiders see? How many eyes do spiders have? Do they have poor vision? If you want to know such lesser-known facts about spider eyes, you’ve come to the right place.
1. Taxonomy of Spiders
The branch of science, taxonomy deals with the classification of organisms. Since you’re curious about spider eyes, you should learn a little about spiders.
Spiders fall under the phylum Arthropoda of the Kingdom Animalia. Arthropods are different from others in terms of their joint limbs. Their cuticles are made of chitin. They have bilaterally symmetrical bodies.
But spiders don’t completely match other arthropods in their profile. Their body segments are combined into two tagmata. Spiders have eight legs arranged bilaterally. They use one out of these four pairs of legs as hands.
But how many eyes do spiders have?
2. Where Are Spiders Found?
Spiders are known to be found all over the world other than Antarctica.
Spiders are diversified in nature. They can take shelter anywhere. They can survive even in extreme climatic conditions. They don’t get bothered by the dry climate. They can manage their water level from their food sources.
3. What Kind of Eyesight Do Spiders Have?
When it comes to eyesight, spiders are not much evolved. They can’t see in the same way as we humans do with just one pair of eyes. How many eyes do spiders have? And how many eyes do humans have? Even though there is a huge difference in the count of eyes, they don’t have as good vision as humans. Most spiders can’t see properly even after using secondary eyes with their principal eyes.
Among all the species of spiders, jumping spiders are known to have the best eyesight. Jumping spiders are blessed with trichromatic vision which enables them to see the true colour.
Spider eyes have lenses better in image brightness. They are even better than photographic lenses. But they still can’t see clearly. They see images of lesser resolution and lesser focus. This happens because their photoreceptors are different from humans.
So, how many eyes do spiders have? And how do spiders sense their prey?
4. How Many Eyes Do Spiders Have?
Now you must be wondering about the eyes of spiders. So, how many eyes do spiders have? Most spiders like wolf spiders have eight eyes. They are located in the middle part of the spider’s head.
With more than 38000 species of spiders, it is natural to find variations among spiders. These variations can also be seen in the number of eyes they have.
Many species of spiders have more than eight eyes. A few species of spiders are also found with less than eight eyes.
There are many varieties of spiders with no eyes or with an odd set of eyes.
5. Why Do Spiders Have So Many Eyes?
You have learnt about the eyesight of spiders. How many eyes do spiders have? What variations do you find in different species of spiders? It is time to know why spiders have so many eyes.
Every species and every organism has evolved over the years. They adapt to different environmental factors and change themselves accordingly. Spiders have also evolved in the same manner. But spider eyes have not evolved as human eyes.
Human eyes are more complex and one pair of human eyes can do a lot of work altogether. But spiders have eight eyes which results in the presence of compound eyes. The eyes on the spider’s face are fixed on its place and they don’t move. They don’t have complex eyes. They have different eyes with a single lens for different functions.
Jumping spiders have central eyes for seeing shapes. The eyes in the middle of their head detect motion. But their side eyes just look for predators.
One more aspect of spiders having multiple eye pairs is the absence of necks in spiders. The absence of necks in spiders restricts their motion and doesn’t allow them to look around. To see in different directions, spiders need more eyes. These secondary eyes help them to stalk prey.
How many eyes do spiders have? Eight! And yet it does not ensure clarity. Even though spiders have eight eyes, they don’t have great depth perception.
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6. Does a Spider Have Good Eyesight During the Day?
There are a few species of spider families such as the day active jumping spiders and flower spiders which hunt during the daytime. These spiders rely on daylight for clear vision.
The eyes of daylight hunters don’t work only for excellent vision. They can sense movement of greater speed. This quality not only helps them in hunting but saves them from predators.
Female jumping spiders tend to attract mates by using ultraviolet light. The ultraviolet light falls on organs named palps situated below their eyes. The light shines and attracts male spiders.
7. Night Vision in Spiders
Some spider species exist which prefer hunting at night. They don’t only use their principal eyes for hunting. They use secondary eyes with their principal eyes to detect dim light. In this manner, they use as much light as they use for catching the prey.
A net-casting spider is known to have two big eyes on the back of its head. It provides them with a wider field to sense distant and nearby objects. Net-casting spiders use these secondary eyes for night vision. In net-casting spiders, the old light-sensitive membrane is destroyed and a new light-sensitive membrane is made every morning.
8. How Does a Spider Catch Prey?
In most spiders, the front eyes help in identifying the prey. Front eyes allow them to hunt. At the same time, side eyes detect motion. Side eyes ensure safety during hunting.
The presence of median eyes in some species of spiders helps to detect polarised light. Navigation, thus, becomes easier during hunting.
9. Final Thoughts
A spider is a very fascinating creature. No matter how many eyes a spider has, a spider still catches its prey. Other senses of a spider also get active for helping it in detecting motion.
In this article, you have learned interesting facts about spiders. How many eyes do spiders have? How do spider eyes work? So, please tell us in the comment section what made you truly amazed.