Carrying out research about spiders seems cool, but the first requirement is knowing how to identify the spider you’re researching on, how can you tell how many eyes do spiders have? As we know, the name spider is a general name for this pest.
There are thousands of spider species still in existence which all belong to different families, kingdom, phylum, and subphylum, order, and suborder.
These spiders can’t all have similar eyes and body parts, in our previous article “the huntsman spider“, we discussed on facts about the huntsman spider and we unveiled secret about the spider. In this discussion, our focus point is “how many eyes do spiders have?”, however, the answers to the question are answered here, read on.
How to Identify a Spider Eyes
They are more than 45,000 species of spiders in the world, identify a spider can be a bit complicated, spiders do look alike, moreover, most people once they find any creepy crawly with eight legs, they conclude with, it is a spider without being able to identify the spider species.
In this article, all you need to know about identifying a spider is discussed so you won’t have to worry anymore.
They are several features that can be used to identify a spider, first, to get it right, you need to know the specie of the spider. You can identify a spider with its eyes when doing this, the ALE (Antero Lateral Eyes) is the first eye you will find in a spider.
It is usually at the top row on the side of the spider’s head, however, the second set of eyes you will find on a spider is the PLE (Postero Lateral Eyes) it is still located on the side of the spider’s head but below the ALE.
The last set of eyes you will find on a spider is the PME (Postero Median Eyes), the sets of eyes are located in the middle region of the spider’s head usually in pairs.
A good number of spiders have their eyes located in this manner while some have secondary sets of eyes located in a forehead, both sides of their head, or the back of their head. Moreover, a major way of identifying a spider is by its color and size. Tho, the spinnerets, and its legs are also good identification factors.
As we mentioned earlier, we said that identifying a spider would no longer be a problem as far as you are reading this article. Below, we have identified all the spider species together with the set of the spider’s eyes.
8 sets of eyes: We identified that spider with this set of eyes is mostly the jumping species of spiders, wolf spiders, cobweb weavers spiders, and the orb weavers spiders.
6 sets of eyes: Another species of spiders have this set of eyes are the brown recluse, spitting spiders, and the cellar spider.
4 sets of eyes: The spiders dominating this set of eyes usually belong to the Nesticide and symphytognathidae families.
2 sets of eyes: It is only spiders from the caponiidae family that have this set of eyes.
Small eyes: The species of spiders that have small eyes are usually underground or cave spiders. In few cases, they appear to have no eyes or undeveloped eyes as a result they hardly see, these spiders do come from the species of spiders with 8 sets of eyes.
Types of Spider Eyes
Well, in our previous paragraph if you read through carefully, you will understand that we discussed the types of spider’s eyes. However, in this paragraph, we will be going into further details about the types of spider eyes.
The spider has 2 major types of eyes, the primary and the secondary eyes. The primary eyes are otherwise known as ocelli, it can also be called Antero-media eyes.
The ocelli enable the spider to see things in an image form, this eye is made up of muscles connected to the retina helping the spider to have a focus vision. It is a well-known fact that spiders have low visibility, well, in the jumping specie of spiders the ocelli (the primary type of eye) has the best image vision better than that of dragonflies and close to that of human beings.
However, the secondary eyes can also be known as the compound eyes, these sets of eyes are usually smaller than the primary eyes, they don’t contain muscles as the ocelli and are totally unable to move.
These eyes are usually oval or circular in shape, they are easily identified because of the position it is located which is usually at the side of the spider’s head. It is otherwise known as the PME (Posterior Median Eyes).
However, even though they don’t move, they still serve lots of vital uses. These eyes can laterally increase in sizes, it is used to detect movement, enabling the spider to track distance as well as tracking its prey’s coordinate, it also helps the spider in detecting threats.
Most spiders especially the nocturnal kinds of spiders have a tapetum lucidum in their eyes, this enables light reflection helping them to see clearly in dim areas. It is known that spiders that have this feature, their eyes do shine when they come in contact with light at dark places or at night.
How Many Eyes Do Spiders Have?
Most Arachnologists identifies spiders mostly with the eyes, as we mentioned earlier, spiders could be classified with their eyes. Research shows that about 99% of spider tends to have 8 eyes classified into 2 types ( primary and secondary sets of eyes).
Well, answering this question, from my research so far, I would conclude that spiders have 8 eyes. However, the placement of these eyes is the key factor used to identify this spider species.
Why do Spiders have many Eyes?
Most people may find it difficult to attempt a query like this. Well, it important a spider has enough eyes because its cephalothorax cannot turn nor twist.
However, having many eyes placed all around its head will easily do the work of turning and twisting to get a view. Most spiders are predators, many eyes enable them to detect movement easily in their environment.
Just as we humans enjoy clear vision with our 2 eyes the same is applied to the spiders. The spider enjoys the comfort of tracking preys and clear vision with its multiple eyes. How many eyes do spiders have? Going through this article, we believe all doubts about it are clear. To contribute or suggest any idea, you’re free to write to us.