Orb weaver spider

Fig. 7. Silk gland distribution from a typical orb weaver spider (modified from Vollrath, 2000b). Within its abdomen the spider produces up to seven different silks in different glands, all with specific functions (copyright 2000, Elsevier).

This compound is the toxin used by the orb weaver spider to paralyse its prey ... 

This compound is the toxin used by the orb weaver spider to paralyse its prey. Notice that it has a guanidine at its right-hand end. These are stable imines,... 

This complex web was spun by an orb weaver spider in Costa Rica. It is composed of a natural polymer. ( Michael Patricia Fogden/Corbis)... 

Adams ME, Carney RL, Enderlin FE, Fu ET, Jarema MA, Li JP, Miller CA, Schooley DA, Shapiro MJ, Venema VJ (1987) Structure and biological activities of three synaptic antagonists from orb weaver spider venom. Biochem Biophys Res Commun 148 678-683... 

As shown earlier, orb weavers like the garden spider Araneus or the golden silk spider Nephila coat the capture threads with an aqueous solution that forms sticky droplets. Coat and droplets are crucial for the function of these capture threads as their elasticity derives largely from the high water content of the coat. However, water is important not only for these threads, but for many other types of thread as well, and the role of water as well as other solvents for understanding and manipulating the mechanical properties of spider silk caimot be understated (Fig. 8.9). This can be of special interest if we aim to produce bio-engineered silks with specific properties. 

Other animals create powerful weapons against their preys spiders are sticky traps master-builders. As an example, the Golden Orb Weaver spins a tough web which remains as a permanent fixmre, after that she spins a spiral of sticky insect-ensnaring silk and then she just waits and collects her reward. Many spiders wrap up their victims with silk, but they loll them by venom injection. There are some rare spiders... 

A postsynaptic target for venom toxins is the receptor channel activated by the neurotransmitter glutamate 0 4 in Figure 1). In this case, aromatic polyamines from orb weaver venoms (argiotoxins 18-20) or funnel web spider venoms (a-agatoxins 12,21-23) bind the channel in its open state, causing a block following activation by the transmitter. 

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