BIOL 005B Lecture Notes - Lecture 8: Swim Bladder, Acanthopterygii, Carina Round
Document Summary
Biol 005b lecture 8: deuterostomia, craniates, vertebrates, gnathostomes. Formation of the mouth at the end of the embryo opposite the blastopore , anus formed from blastopore. Sea stars and most other echinoderms are slow-moving or sessile marine animals. A thin epidermis covers an endo skeleton of hard calcareous plates. Simple nerve net with some central coordination. Echinoderms have a unique water vascular system , a network of hydraulic canals branching into tube feet that function in locomotion, feeding, and gas exchange. Males and females are usually separate, and sexual reproduction is external. Chordates share a set of derived characters; some species have some of these. Four key characters of chordates: traits only during embryonic development. The notochord is a longitudinal, flexible rod between the digestive tube and nerve cord. It provides skeletal support throughout most of the length of a chordate. In most vertebrates, a more complex, jointed skeleton develops, and the adult retains only remnants of the embryonic notochord.
