BIO SCI 94 Lecture Notes - Lecture 15: Rigid Body, Onychophora, Chelicerata

• School: UC-Irvine
• Department: Biological Sciences
• Course: BIO SCI 94
• Professor: Robin Bush

Document Summary

They do not have the three traits that define the lophotrochozoans. The two groups can be differentiated using dna data. Ecdysozoans grow intermittently by molting: shedding of the soft cuticle or hard. Ecdysozoans undergo a succession of molts as they grow. Once the animal molts, fluid causes the body to expand, and a new, larger cuticle or exoskeleton forms. In insects, the presence or absence of a larval stage defines two distinct types of metamorphosis. Larvae: an immature stage of an animal species in which the immature and adult stages have different body forms: holometabolous metamorphosis (complete metamorphosis) There is a distinct larval stage: hemimetabolous metamorphosis (incomplete metamorphosis) No larval stage: holometabolous metamorphosis (complete metamorphosis) Larvae and adults often live in different habitats and feed on different foods. In holometabolous metamorphosis, larvae stop feeding and moving and secrete a protective case, becoming a pupa (also not present in hemimetabolous metamorphosis).