Spider web

Spider Web

A spider web, also known as a cobweb, is a structure created by a spider out of proteinaceous silk extruded from its spinnerets. Spider webs are used primarily for catching prey, but they also serve other functions such as shelter, reproduction, and communication.

Structure and Composition

Spider webs are composed of silk, which is a protein fiber spun by spiders. The silk is produced in the silk glands and extruded through the spinnerets located at the rear of the spider's abdomen. The silk is initially a liquid protein solution that solidifies upon contact with air.

There are several types of silk, each with different properties and functions:

• Dragline silk: Used for the web's frame and radii, known for its strength and elasticity.
• Capture spiral silk: Sticky and elastic, used in the spiral part of the web to capture prey.
• Tubuliform silk: Used for egg sacs.
• Aciniform silk: Used to wrap prey.

Types of Spider Webs

There are several types of spider webs, each adapted to the spider's environment and hunting strategy:

• Orb webs: Circular webs with a central hub, constructed by orb-weaver spiders. These are the most familiar type of web.
• Sheet webs: Flat, horizontal webs built by sheet-weaving spiders.
• Tangle webs: Irregular, messy webs constructed by cobweb spiders.
• Funnel webs: Funnel-shaped webs with a retreat, built by funnel-web spiders.

Functionality

Spider webs serve multiple purposes:

• Prey capture: The primary function of a web is to trap insects and other small animals. The sticky silk of the capture spiral ensnares prey, allowing the spider to subdue it.
• Shelter: Webs can provide a safe retreat for spiders from predators and environmental hazards.
• Reproduction: Some webs are used to protect egg sacs or as a site for mating.
• Communication: Vibrations transmitted through the web can inform the spider of prey capture or the presence of a mate.

Ecological Importance

Spider webs play a crucial role in ecosystems by controlling insect populations. They are also a source of food for other animals, such as birds and wasps, which may consume the silk or the spider itself.

Human Applications

Spider silk has been studied for its potential applications in materials science due to its strength and elasticity. Researchers are exploring its use in creating biodegradable fishing lines, medical sutures, and even bulletproof clothing.

Also see

• Spider
• Silk
• Orb-weaver spider
• Insect
• Predation