Spiders (Araneae) are one of the most diverse orders within the animal kingdom, with more than 42,000 species described. They are related to mites, scorpions and harvestmen, among other groups. All together they form the class of arachnids called Arachnida.
Spiders are distributed throughout the world and have adapted to live in very different habitats. As a result, their diet is diverse and dependent on where they live. In fact, some spiders are highly specialized for a single type of food. You want to know more? In this article on our site we tell you what spiders eat
Types of spiders
The classification of spiders is fundamentally based on the arrangement of the chelicerae. These are mouthparts that have a nail with which they inject poison. Therefore, its knowledge is essential to understand what spiders eat.
Currently, there are three types of spiders:
- Araneomorphs (suborder Araneomorphae): This group includes most of the existing spider families. The main characteristic common to all of them is the presence of labidognathic chelicerae, that is, they move at right angles to the axis of the body.
- Migalomorphs (suborder Mygalomorphae): is the group of tarantulas, trapdoor spiders and other close relatives. These arachnids have orthognathic chelicerae, that is, they move parallel to the body.
- Mesothelos (suborder Mesothelae)-Includes only one living family, the liphistids (Liphistidae). These are the most primitive spiders, which do not have venom, although they do have orthognathic chelicerae that can produce a strong bite.
Are spiders carnivorous?
So, if chelicerae are used to bite and/or inject venom, are spiders carnivorous? The answer is yes, most spiders are carnivorous. There is only one known exception, a herbivorous spider that we will see later.
Spiders are predatory animals that capture other arthropods and inject them with venom to paralyze or kill them before eating them. In reality, most spiders do not eat their prey, but absorb their internal fluids until they are completely dry.
Spider feeding
Spiders feed based on insects, although they can also feed on other arachnids. Larger spiders, such as the giant tarantula (Theraphosa blondi), can eat mice and lizards.
Although considered carnivorous, many species of spiders consume small amounts of plant matter, such as nectar from flowers. This behavior has been recorded, for example, in many species of the S alticidae family. In addition, as we already anticipated, there is a single species of spider that consumes mainly vegetable matter. Therefore, it is considered a herbivorous spider. Let's meet her!
What do herbivorous spiders eat?
Bagheera kiplingi is the only herbivorous spider known so far. It is a s alticide that has a mutualistic relationship with ants of the genus Pseudomyrmex. Both ants and spiders live in acacias of the genus Vachellia, which have reddish tips on their leaves known as Beltian bodies. It is a food that plants produce specifically for ants. In return, they defend the plants from herbivorous animals.
Beltian bodies are the main food of herbivorous spiders, which help ants protect acacias. In addition, they consume extrafloral nectar that the plants also produce for the ants. However, very occasionally, spiders also feed on small insects, such as flies, and the ants' own larvae.
What do carnivorous spiders eat?
To catch their prey, carnivorous spiders have developed all kinds of strategies: webs, trapdoors, camouflage, fishing rods… According to their predation strategies, we can differentiate several types of carnivorous spiders:
- Weaver spiders
- Trapdoor spiders
- Spiders that camouflage themselves
- Boleadora spiders
- Jumping Spiders
Weaver Spiders
Most spiders have a spinning gland that produces and secretes silk. Weaver spiders are those that use silk to build the famous webs Normally, they camouflage themselves on the edge of the web, waiting for prey to be trapped. When this happens, a vibration is generated that indicates to the spider that the food is served.
The prey that usually falls into these traps depends on the morphology of the web, which is different in each type of weaver spider. Those that make large circular webs tend to trap flying insects However, those that weave the web in holes in the ground catch other types of insects, such as those that walk or They seek moisture.
Many families of spiders are web weavers and these are the most common examples of weaver spiders:
- Araneids (Araneidae): here we find the garden spider (Araneus diadematus) and the black and yellow garden spider (Argiope aurantia).
- Therididae (Theridiidae): is the family of the black widow (Latrodectus mactrans).
Trapdoor Spiders
Trapdoor spiders build burrows in the ground To do this, they dig and reinforce the walls with silk. Some also use the silk to build a door, to which they may add clay. Others, such as the genus Cyclocosmia, cover the burrow exit with their characteristic abdomen. Once the shelter is ready, they hide inside and only come out to hunt or mate.
Some trapdoor spiders lay threads on the outside to detect movement when prey steps on them. Others are able to perceive ground vibrations. When this happens, they open the trapdoor and pounce on their prey.
Spiders that use trapdoors to catch their prey are in the following families:
- Liphistiidae (Liphistiidae): they are all Asian, like the kimuro spider (Heptathela kimurai).
- Ctenízidos (Ctenizidae): one of the best known is Cyclocosmia loricata, a species from Mexico and Guatemala.
- Idiopids (Idiopidae): Idiosoma hirsutum is one of its best representatives.
Spiders that camouflage themselves
There are many spiders that bury themselves or camouflage themselves in the groundSome even accumulate dirt particles on their backs, so that they are indistinguishable from the substrate. This is the case of Paratropis tuxtlensis. Others have much more sophisticated camouflage mechanisms that allow them to specialize in certain prey.
A curious example is that of the crab spiders (family Thomisidae), which camouflage themselves in flowers. To do this, they adopt their same color thanks to the production of pigments. In this way, they wait for pollinators to approach the flower. When this happens, they are injected with a poison that paralyzes them and sucks out their internal fluids.
Other spiders that camouflage themselves are known as pirate spiders (family Mimetidae). What do pirate spiders eat? These spiders go to the webs of their weaver relatives and move the silk to simulate that a prey has been trapped. The owner of the fabric in question does not hesitate to go for her snack. However, she is the pirate spider's snack.
Boleadora spiders
Boleadora spiders use their silk to build a sticky ball attached to a thread. It is a kind of fishing rod that has pheromones to attract flying insects, which constitute the food of these spiders. These remain attached to the ball until the spider paralyzes them and wraps them in silk. Some species can launch the ball directly at their prey, such as a cowboy throwing a rope to catch a horse.
Three genera of Bola spiders are known:
- Mastophora
- Cladomelea
- Ordgarius
Jumping Spiders
S alticids or jumping spiders (family S alticidae) are small spiders that hunt their prey by jumping on them. To do this, they stick a thread to the branch or rock they are on and launch themselves towards the prey as Spiderman would. Others, however, remain hanging from this thread until prey passes below.
