BIO SCI 94 Lecture Notes - Lecture 12: Hemimetabolism, Crustacean, Arthropod

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

Document Summary

They don"t have the three traits that define the lophotrochozoans. The two groups can be differentiated using dna data. Lophotrochozoans grow continuously and incrementally while ecdysozoans grow intermittently by molting: shedding of the soft cuticle or hard exoskeleton. 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) - has distinct larval stage. Larvae and adults often live in different habitats and feed on different foods in holometabolous metamorphosis, larvae stop feeding and moving and secret a protective case, become a pupa (also not present in hemimetabolous metamorphosis). During pupation, the pupa"s body is completely remodeled into a new, adult form.