What are Spiders?
Spiders have two main body parts:
- Spiders have two body segments. The front segment is called the Cephalothorax. The spider’s eyes, mouth fangs, stomach, brain and the glands that make the poison are on this part of the body. The eight legs are connected to this part as well.
- This sets them apart from insects, which have only 6 legs. The legs are usually long and hairy. The hairs on their legs are used to pick up scents, sounds, vibrations and to detect air currents.
- Most spiders have eight eyes. Some have no eyes and others have as many as 12 eyes. Most can only differentiate between light and dark, while others have well-developed vision.
- At the front of the cephalothorax we find fan-like or claw-like appendages which are their mouthparts, called chelicera. In spiders these chelicera are hollow and contain venom glands and are used to inject poison into its prey.
Where do spiders live?
SPIDERS ARE EVERYWHERE
During their long history, spiders have evolved into thousands of different species and spread all over the world. Spiders live in almost every habitat on earth, except for the polar regions, the highest mountains and the oceans. A few spider species have invaded the ocean’s edge, living in the rock and coral crevices of the intertidal zone.
How many species of spiders are there?
Currently, over 35,000 spiders are known worldwide. 3,000 species in North America alone. Biologists and naturalists believe that many spider species are still to be identified and named.
Spiders are not insects.
Spiders are arachnids not insects, but both spiders and insects belong to the largest group of animals on Earth, the arthropods (Ancient Greek: arthro = joint, podos = footed) – animals with hard external skeletons and jointed limbs .
A few spiders are very small and live such hidden lives that most of us never see them. Others are enormous like the huntsman spider.
Some of the smallest spiders in the world are anapid spiders, sometimes called armoured spiders because of the cuticular plates on their pinhead-sized bodies. Small spiders like anapids are usually found in damp, cool habitats like forest leaf litter and moss because their small bodies can lose water rapidly in dryer conditions. The largest spiders in the world include the South American Goliath Tarantula, some so big their legs can span a dinner plate. Such spiders may take decades to reach such a size. However, spider size is limited, partly because their respiratory physiology becomes less efficient at very large sizes.
Many spiders have unusual body shapes and colours.
Bizarre bodies can be helpful to spiders in various ways – to deceive and ambush prey, to capture particular sorts of prey, to avoid being eaten and to attract mates.
Control Pest Management experts are trained to recognize all the different species in your locality.
FUNNEL-WEB SPIDERS
Funnel-web spiders, are the most notorious members of our spider fauna and are found in eastern Australia.
There are at least 40 species of funnel-web spiders and they vary from 1 cm – 5 cm body length. Body colour can vary from black to brown but the hard carapace covering the front part of the body is always sparsely haired and glossy.
Not all species are known to be dangerous, but several are renowned for their highly toxic and fast acting venom. The Sydney Funnel-web Spider, is probably responsible for all recorded deaths (13) and many medically serious bites.
Identifying Funnel-web Spiders
- Shiny carapace
- Deeply curved groove (fovea)
- No obvious body pattern
- Eyes closely grouped
- Four spinnerets, largest with last segment longer than wide
- Lower lip (labium) studded with short, blunt spines
- Modified male second leg (usually with a mating spur or grouped spines)
Where Funnel-web spiders live
Funnel-web spiders live in the moist forest regions of the east coast and highlands of Australia from Tasmania to north Queensland. They are also found in the drier open forests of the Western Slopes of the Great Dividing Range and South Australia’s Gulf ranges.
Funnel-webs burrow in moist, cool, sheltered habitats – under rocks, in and under rotting logs, crevices, rot and borer holes in rough-barked trees. In gardens, they prefer rockeries and dense shrubberies, and are rarely found in more open situations like lawns. The most characteristic sign of a Funnel-web’s burrow is the irregular silk trip-lines that radiate out from the burrow entrance of most species. These trip-lines alert the spider to possible prey, mates or danger.
How to spot them
Funnel-web burrows are distinguished from other holes in the ground by the presence of a series of irregular silk ‘trip-lines’ radiating out from the entrance. If a spider burrow has obvious silk trip-lines around its rim you can be fairly certain that it belongs to a funnel-web spider.
First aid for Funnel-web Spider bites – why and how
Despite the availability of an effective antivenom, correct and immediate first aid is still an essential requirement for funnel-web spider (and mouse spider) envenomation. The recommended first aid technique is pressure/immobilisation (as for snake bite) and this must be done as quickly as possible.The pressure/immobilisation technique compresses surface tissues and reduces muscle movement, greatly slowing the lymphatic flow.
Spider bites usually take place on a limb. A pressure bandage should be applied as soon as possible after a bite has occurred. This should be applied as tightly as for a sprained ankle, starting from the bitten area and binding the entire limb above the bite. A rigid splint should be bound onto the limb to prevent limb movement. The patient should be kept as quiet as possible and medical attention sought. If possible, keep the spider for positive identification.
