(2) Ecdysis, or the actual shedding of the old exoskeleton, takes place when the old exoskeleton splits along preformed lines. In the lobster it splits between the carapace and the abdomen, and the body is withdrawn through the hole, leaving the old exoskeleton almost intact.

Why ecdysis occurs in arthropods?

Ecdysis is the process of an arthropod moulting its exoskeleton. Moulting is necessary as the arthropod exoskeleton is inflexible and so, to grow larger, arthropods must moult. ... Their existing cuticle weakens at specific points and by taking in water or air the animal splits its old exoskeleton.

What causes ecdysis?

Ecdysis is triggered by ETH (Ecdysis triggering hormone), and the response of peptidergic neurons that produce CCAP (crustacean cardioactive peptide), which are key targets of ETH and control the onset of ecdysis behavior, was shown to depend fundamentally on the actions of neuropeptides produced by other direct ...