Ecdysozoa Defined: the Molting Cuticle
This video presents the same text shown beside it, spoken and on screen. It adds nothing the text does not say.
State
Ecdysozoa groups protostome, per Bio 2225, phyla whose members grow by molting a rigid outer cuticle: nematodes, tardigrades, and arthropods.
Show
A growing nematode periodically sheds its old cuticle and secretes a larger one underneath, a process called ecdysis.
Watch for
A rigid cuticle that cannot stretch makes molting necessary for growth in this clade — Lophotrochozoa phyla do not share this constraint.