1. Spider bodies consist of two parts, the cephalothorax and the abdomen.
All spiders, from tarantulas to jumping spiders, share this common trait. The simple eyes, fangs, palps, and legs are all found on the anterior body region, called the cephalothorax. The spinnerets reside on the posterior region, called the abdomen. The unsegmented abdomen attaches to the cephalothorax by means of a narrow pedicel, giving the spider the appearance of having a waist.
2. With the exception of one family, all spiders are venomous.
Spiders use venom to subdue their prey. The venom glands reside near the chelicerae, or fangs, and are connected to the fangs by ducts. When a spider bites its prey, muscles around the venom glands contract, pushing venom through the fangs and into the animal. Most spider venom paralyzes the prey. The spider family Uloboridae is the exception to this rule; its members do not possess venom glands.
3. All spiders are predators.
Spiders hunt and capture prey. The majority feed on other insects and other invertebrates, but some of the largest spiders may prey on vertebrates such as birds. The true spiders of the order Araneae comprise the largest group of carnivorous animals on Earth.
4. Spiders can’t digest solid foods.
Before a spider can eat its prey, it must turn the meal into a liquid form. The spider exudes digestive enzymes from its sucking stomach onto the victim’s body. Once the enzymes break down the tissues of the prey, it sucks up the liquefied remains, along with the digestive enzymes. The meal then passes to the spider’s midgut, where nutrient absorption occurs.
5. All spiders produce silk.
Not only can all spiders make silk, but they can do so throughout their life cycles. Spiders use silk for many purposes: to capture prey, to protect their offspring, to assist them as they move, for shelter, and to reproduce (more on that in a moment). Not all spiders use silk the same way.
6. Not all spiders spin webs.
Most people associate spiders with webs, but some spiders don’t construct webs at all. Wolf spiders, for example, stalk and overtake their prey, without the aid of a web. Jumping spiders, which have remarkably good eyesight and move quickly, have no need for webs, either. They simply pounce on their prey!
7. Male spiders use modified appendages called pedipalps to mate with females.
Spiders reproduce sexually, but males use an unusual method to transfer their sperm to a mate. The male first prepares a silk bed or web, onto which he deposits sperm. He then draws the sperm into his pedipalps, a pair of appendages near his mouth, and stores the semen in a sperm duct. Once he finds a mate, he inserts his pedipalp into her genital opening and releases his sperm.
8. Males risk being eaten by their female mates.
Females are typically larger than their male counterparts. A hungry female may consume any invertebrate that comes along, including her suitors. Male spiders often use courtship rituals to identify themselves as mates and not meals. Jumping spiders perform elaborate dances from a safe distance and wait for a female’s approval before approaching. Male orb weavers (and other web-building species) position themselves on the outer edge of the female’s web, and gently pluck a thread to transmit a vibration. They wait for a sign that the female is receptive before venturing closer.
9. Spiders use silk to protect their eggs.
Female spiders deposit their eggs on a bed of silk, which she prepares just after mating. Once she produces the eggs, she covers them with more silk. Egg sacs vary greatly, depending on the type of spider. Cobweb spiders make thick, watertight egg sacs, while cellar spiders use a minimum of silk to encase their eggs. Some spiders produce silk that mimics the texture and color of the substrate on which the eggs are laid, effectively camouflaging the offspring.
10. Spiders don’t move by muscle alone.
Spiders rely on a combination of muscle and hemolymph (blood) pressure to move their legs. Some joints in spider legs lack extensor muscles entirely. By contracting muscles in the cephalothorax, a spider can increase the hemolymph pressure in the legs, and effectively extend their legs at these joints. Jumping spiders jump using a sudden increase in hemolymph pressure that snaps the legs out and launches them into the air.
Studies have shown that you’re never more than ten feet away from a spider, and one estimate puts you as close as three feet. To be “spider-free” you’d have to go into space in a fumigated capsule. Rather than flee, read these facts and appreciate our amazing arachnids.
Unlike insects, spiders cannot fly–but they can balloon! Young spiderlings pull out silk until the breeze can lift them into the sky. Most don’t travel high or far, but some have been seen at altitudes of 10,000 feet and on ships more than 200 miles from land. Most ballooners are very small spiderlings, but adult spiders have been captured by planes with nets.
Female wolf spiders carry their egg sacs behind them, attached to their spinnerets. After the spiders emerge, they crawl onto the mother’s abdomen and hold on while she actively runs and hunts. After about a week, the spiderlings molt to a larger size and then take off to live on their own.
While most spiders live for one year, a few may have more than one generation each year. Some spiders can live 3 to 4 years, and certain tarantulas are known to live for 25 years or longer.
Male spiders are almost always smaller than the females and are often much more colorful. Some males are so small that they actually look like they’re newly hatched.
Male spiders are unique among all animals in having a secondary copulatory organ. While most animals spread their sperm in water or insert them into the female, mature male spiders weave a small “sperm” web. They place a drop of semen on the web, suck it up with their pedipalps (special structures on their first “arm”), and then use the pedipalp to insert the sperm into a female.
Some spiders live underwater all of their lives. They surface to collect a bubble of air, which acts as an underwater lung. An underwater spider fills its bell-shape web with air bubbles and derives oxygen from them.
The fisher or raft spider is able to walk across the surface of a pond or other body of water by skating like a water strider. When it detects prey (insects or tiny fish) under the surface, it can quickly dive to capture its dinner.
Spiders are not only predators, they are often prey. Many birds and animals love to feed on them. The coatimundi, a relative of the raccoon, are fond of eating large tarantulas.
Hummingbirds use the silk from spider webs to weave together the sticks that form their nests.
A few species of trapdoor spiders use their abdomens to “plug” their burrows to protect themselves from wasps. The abdomen is flat on the back end and tough enough that a wasp’s stinger can’t penetrate it.
Spiders eat more insects than birds and bats (combined) eat, so they should be considered another of human’s best friends. They play a big role in controlling insect populations.
The decoration in the web of some orb-weaving spiders serves a variety of purposes: It can be a warning so birds don’t fly into the web, an attractant so insect-prey fly in on purpose, or an “um-brella” to shade the spider from the hot sun.
Some orb weavers make very unusual webs. One variety greatly increases the area above the center, creating what is sometimes called a ladder web that extends eight feet above the spider.
Bolas spiders make webs of a single line with a sticky “ball,” or bola, on the end. These spiders can twirl the bolas in the air. Moths are attracted to the smell and fly toward the web until they hit it and stick. The spider then reels in its catch.
This article was adapted from “The Book of Incredible Information,” published by West Side Publishing, a division of Publications International, Ltd.
Some Videos with more information….If you can handle it 🙂
1. Insect Control
Spiders eat more insects than birds and bats combined, so they should be considered one of human’s best friends. They play a big role in controlling insect populations.
2. Spider Silk
Spider silk is incredibly strong and flexible. Some varieties are five times as strong as an equal mass of steel and twice as strong as an equal mass of Kevlar. This has attracted the attention of scientists in a number of applied science fields, but up until recently, humans haven’t been able to get much out of this natural resource. It’s simply too hard to extract silk from spiders, and each spider has only a small amount of it.
Spiders use their silk in a variety of ways, as we will see below, but Orb weavers are the spiders most of us are familiar with – the type that builds webs in trees and bushes and the corners of our ceilings. When the orb web has deteriorated and is no longer useful, many spider species will destroy it, eating up all the threads so it can recycle the raw silk material. Spiders may leave the heavy bridge thread so that they can easily rebuild the web at a later point.
3. Jumping Spiders
Jumping spiders, one of the more common types of spiders world-wide, have the ability to jump great distances — as far as 50 times their own length. The thing that is the most amazing about these jumpers is that they don’t have particularly strong muscles in their legs; they actually spring forward using hydraulic pressure. A powerful muscle in the cephalothorax squeezes fluids from the body into the legs to make them expand.
With more than 5,000 species around the world, jumping spiders are one of the more common spider varieties around. They’re characterized by large eyes, which help them spot potential prey at a good distance. In contrast to web-spinning spiders, most jumping spiders hunt sort of like cats, stalking their prey and then springing on them at high speed.
This next video shows a Brazilian Wandering Spider fending of a Tarantula Hawk (Spider Wasp).
I hope this has left you all sufficiently grossed out 🙂 If not however, then here is another small selection of pictures to seal the deal.