Spiderschool

Spiders are arthropods from the order Araneae who inhabit the entire world except in the cold regions of Antarctica. There are approximately 40,000 species and 109 families. The entire body of the arthropod consists of two segments the cephalothorax and the abdomen which are joined by cylindrical pedicel. Except for some primitive species these have a fully evolved nervous system and muscular system which displays movement through hydraulic pressure. Their physiology displays a well demarcated nervous, circulatory, reproductive, respiratory, digestive and excretory system. The digestion by the spiders is external, where the prey is suffocated with a sting of the venom and then digestive juices are released. After liquefaction, the feed is ingested. According to nyfa the excretion of spiders is not messy as it is uric acid extruded as a dry material.

The prey of spiders is generally hunted and a few wait for the prey to get captured in their webs. Reproduction in spiders is through courtship and some species cannibalise their male counterparts after mating. Most spiders do not bite, but a few have a venomous bite which can cause death when not treated immediately. Nyfa explicitly specifies that the art of keeping some species as pets is attributed to their calm and docile nature.

SILK PRODUCTION BY SPIDERS

All spiders are known to produce silk, but not all species can spin webs. The threads of silk come from spinnerets present along the sides of the abdomen. When released the thread seems to be a single layer but actually it comprises of a number of layers which are adhered by sticky material. The silk can be sticky, dry or stretchy. It is used for climbing, create webs, build burrows, egg sacs, protection and catch prey. A few fish with the silk. A few species discharge silk which is kilometres in length.