Ecdysis

Ecdysis is a biological process by which many arthropods grow. This process, also known as moulting or shedding, involves the animal periodically shedding its exoskeleton (outer protective covering) and forming a new one.

Overview

Ecdysis is a critical part of the life cycle of arthropods, including insects, crustaceans, and arachnids. The process is controlled by hormones and allows the animal to grow by discarding its old, restrictive exoskeleton. The new exoskeleton is initially soft, allowing the animal to increase in size before it hardens and provides protection again.

Process

The process of ecdysis begins with the separation of the old exoskeleton from the underlying skin, or epidermis. This is followed by the secretion of a new exoskeleton beneath the old one. Once the new exoskeleton is fully formed, the animal increases its intake of air or water to expand its body and break open the old exoskeleton. The animal then emerges and the new exoskeleton hardens.

Hormonal Control

The process of ecdysis is controlled by two main hormones: ecdysone and ecdysis-triggering hormone (ETH). Ecdysone is responsible for initiating the process of moulting, while ETH triggers the actual shedding of the old exoskeleton.

See Also

• Arthropod
• Exoskeleton
• Ecdysone
• Ecdysis-triggering hormone

Ecdysis

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  Rhopalomyia solidaginis eclosion
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  Cicada molting animated
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  The arthropods moulting 1
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  The arthropods moulting 2
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  The arthropods moulting 3
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  Crab spider female in ecdysis; Genus Synema, Family Thomisidae
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  Araignée en train de muer