Exoskeleton. Tarantulas have a thick "shell" around them. Not only does it contain all of the organs as well as the open bath circulatory system, but it also protects them from physical harm as well as protecting them from bacteria and fungi. It also serves as points of attachment for the majority of the tarantulas muscles, and helps to stop water loss. The exoskeleton's extensions (bristles, setae, trichobothria) are sensory structures, sensing a wide variety of things around the animal. Frequently, it's color and adornments serve as identifying markers for warning labels for the animal. For the most part it comes in the form of a box made of interlocking plates, or a set of jointed tubes. But, it might be a leathery bag held taut by internal pressure. It resembles a knight's suit of armor with each plate having a different shape, position, function and name. It is constructed with many folds, ridges, and indentations to provide strength, allow attachment of muscles, and allow for movement. It is usually covered in an array of sense organs and defensive bristles. It could be transparent, pigmented, or have iridescent areas. The exoskeleton is usually composed of several different substances. The more important of these is chitin, and sclerotin. These linked together provide for the exoskeletons hardness. The exoskeleton has a waxy layer that is most important to the animal. It provides for the retention of water, preventing desiccation. Definitions | Conversions | WebCam | Search | Guest Book | Forum | Calendar
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