Spiders (order Araneae) are arachnid arthropods, that is, they are related to mites, scorpions and harvestmen. It is one of the most diverse orders in the animal kingdom, with more than 45,000 known species and 114 families. Their great ability to disperse has allowed them to reach all corners of the world. Therefore, it is thought that most of the species are still unknown.
These arachnids have a very curious reproduction, marked by sexual dimorphism, cannibalism and great communication between the female and the male. Due to the great diversity of this group of animals, very varied reproductive rituals have been documented. Do you want to meet them? Don't miss this article on our site about how spiders reproduce In it we tell you curiosities about their courtship, their copulation, their spawning and the birth of their young.
Characteristics of spiders
Before we know how spiders reproduce, we need to know them in more detail. All of them have a series of characters that differentiates them from other arthropods. These are the main characteristics of spiders:
- Terrestrial: All life stages of spiders are terrestrial. There are a few exceptions that spend a lot of time in the water, such as the European water spider (Argyroneta aquatica).
- Octopods: Spiders, like other arachnids, have 8 legs, a characteristic that differentiates them from other arthropods.
- Segmentation: Your body is divided into two parts. The anterior part or “head” is known as the prosoma. This is followed by the opisthosoma, a kind of very enlarged abdomen that houses the animal's viscera.
- Rows: on the back of the opisthosoma they have structures known as rows. Through them they emit silk threads that they use for various purposes, such as building spider webs, transporting themselves or protecting the spawn.
- Pedipalpos: they are appendages similar to legs, although they are raised and in front of the body. They are usually larger in males, who use them during courtship and also as a copulatory apparatus. It is a very important feature to understand how spiders reproduce.
- Chelicerae: these are elongated mouthparts ending in a nail. They use them to inoculate their prey with poison.
- Carnivores: Spiders feed by sucking the internal fluids of other arthropods, especially insects. Many of them supplement their diet with nectar or other plant food sources. Only one herbivorous species is known: Bagheera kiplingi.
- Predators: These arachnids are quite voracious predators. To get their food, they have very diverse hunting strategies: nets, traps, camouflage, etc. If you want to know about them, we will tell you about it in this other article about What spiders eat.
- Poison: After catching their prey, they inoculate it with toxic substances to paralyze or kill it. In addition, the poison may contain substances that dissolve the tissues of the prey. In this way, they turn them into liquids and then suck them up. An exception is the family Uloboridae, which lacks venom glands.
Spider reproduction
We already know these interesting animals very well, but how do spiders reproduce? Let's see it! Reproduction in spiders is sexual, that is, a male and a female gamete unite to form an embryo. For this reason, there are males and females that must copulate for new spiders to be born. Before that, they choose their sexual partner through courtship. This couple is only temporary, since both males and females mate with several individuals in the same reproductive season.
After copulation, females lay tens or even thousands of eggs, depending on the species and weather conditions. Spiders are therefore oviparous animals. Parental care appears in most species. The female usually takes care of the eggs and, sometimes, also of the young. In the following sections we see it in more detail, including the most curious examples.
Spider Courtship
In many spider species there is sexual dimorphism. Often the females are much larger than the males This is often the case in web-building spiders. They are sedentary and always remain hunting in the same place. It is there that the males go to look for them following the trail of their pheromones. In active predators, however, males and females are similar in size, although color differences may appear.
Before copulation, both partners must be sure that they are the ideal partner. To do this, they usually perform a series of wedding rituals. In some species, the male performs a courtship dance to attract the female's attention. This is the case of the “peacock spiders” (Maratus spp.), whose males raise their third pair of legs and make their body vibrate while showing their colorful drawings.
Another strategy to win over females is to give them a bridal gift For example, male Pisaura mirabilis wrap insects in silk and They offer them to the females. Sometimes they try to trick them by offering them an inedible object. If they realize the deception they may decide not to mate. This is because males who cheat often don't put much effort into copulation.
Finally, communication through sounds or stridulations has been documented in many spiders. Some males collide their extremities against each other or against the ground, emitting a kind of "song". These sounds are not usually audible to humans.
Copulation of the spiders
Copulation is the most important process in understanding how spiders reproduce. When the female decides that a male is suitable, he grabs her by the chelicerae thanks to some pincers that she has on her pedipalps. In this way, he lifts her over him and can access her genital pore. She introduces her sperm into it through her copulatory organ, which is also found on the pedipalps. This information is indicative, since the posture adopted during copulation varies in each species.
The introduction of the copulatory organ is repeated several times. The longer the sexual act lasts, the greater the chances that the male will have of being a father. This is because females can copulate with several males, keeping their sperm in their reproductive tract. Therefore, the order of the males is not as important as the amount of sperm that each one is capable of contributing.
During copulation, females usually emit sounds or stridulations. Its function is believed to be to increase or decrease the sexual activity of the male. Thus, the males that get along better with the females could get a greater number of fertilized eggs. This fact occurs, for example, in the cellar spider (Physocyclus globosus).
Another behavior that usually appears before or after copulation is sexual cannibalism Although it rarely occurs, in some species the female can eat the male. This behavior appears in species with sexual dimorphism. In some of these species, they have learned to defend themselves against cannibalism. This is the case of the males of the nursery spider (Pisaurina mira), which wrap the females in silk before copulation.
Spider Breeding Season
The breeding season for spiders depends on the weather conditions where they live. In places where there is a cold and a warm season, spiders reproduce in spring or summer In early spring they reach sexual maturity, begin to secrete pheromones and look for one or more partners. It is not until late spring or early summer that they lay eggs. In this way, spiders spend the winter as juveniles or adults, depending on the species.
In tropical climates, where the cold does not limit spider reproduction, they can lay eggs several times a year In these cases They usually complete their life cycle in just a few months. However, there are many exceptions, since very different factors influence the reproduction of spiders. Some breed in the fall and others lay eggs every 2 or 3 years.
How do spiders lay eggs?
A few days or even several weeks after copulation, the females lay eggs. To do this, they cover the spawn with a silk cocoon and choose a very protected place to leave it. Subsequently, many mothers watch over and protect their eggs until they hatch. Other species prefer to carry the cocoon on their body. In this way, they prevent other animals from preying on them. An example of this is again the Pisarua mirabilis, since the female carries the eggs until they hatch.
Many females do not lay all their eggs at once, but lay several times on different days. Some species wait for the eggs of the first clutch to hatch before carrying out the second clutch. This way, they can take care of all their eggs. So how many eggs do spiders lay? As noted above, they can lay tens or thousands of eggs.
How are spiders born?
All the eggs in the clutch hatch at the same time, that is, all the nymphs hatch at the same time. These are little spiders very similar to their parents. Therefore, the spiders do not have larvae and do not undergo metamorphosis, so their development is direct.
Spider hatchlings or nymphs often stay together for a while. When they learn to hunt, they separate from their sisters and begin to disperse thanks to the wind Normally, they climb to a high place and form a very long silk thread that it will be carried by the wind for miles. Thanks to this strategy, these little animals have been able to reach every corner of the world.
In very few species the spiderlings can remain in the nest for up to 40 days. It is because, during this time, their mothers take care of them. In some spiders, it has even been documented that the females feed their young Some of them could be some of the best mothers in the animal kingdom. This is the case of the jumping spider (Toxeus magnus), which deposits some nutritious droplets next to its nymphs. It is a liquid that it produces itself, which is why it has been compared to the milk of mammals.
How long does it take for spider eggs to hatch?
The time it takes for the eggs to hatch depends on the species. In addition, it is influenced by other factors, such as weather or temperature. In some species, the eggs hatch when conditions are right for it. This can happen in as little as 1 week or be delayed up to 4 months after laying.
As you can see, how spiders reproduce is a difficult question to answer due to the enormous diversity of this group. In the image we see an example of spider Pardosa sp., where the mother carries the eggs and, once they hatch, the spiderlings stay attached to her until they become independent after a few days.
