Deuterostomes

Deuterostomes

  • Phylum Enchinodermata

  • Phylum Chordata

Pattern of Development

  1. Cleavage'

    1. Radial

    2. Indeterminate fate

  2. Fate of blastopore during gastrulation

    1. Blastopore becomes the anus

  3. Development of coelom

    1. Mesoderm pockets pinch off of gut to form coelem

Echinoderms

  1. Sea urchins, sand dollars, sea stars, sea cucumbers

  2. Bottom-dwelling marine animals

  3. Many have spines or spikes

    1. Echinoderm= “spiky skin”

  4. Endoskeleton provides support and protection

Echinoderms

  1. Radial symmetry (adults)

  2. Bilaterally symmetric (larvae)

Echinoderms

  1. Water vascular system

    1. circulating watery fluid used especially for the movement of tentacles and tube feet

    2. Tube feet

Phylum Chordata (Chordates)

  1. At some time during life cycle have

    1. Flexible, supporting notocord

    2. Dorsal hallow nerve cord

    3. Pharyngeal (gill) slits

    4. Post-anal tail

Invertebrate Chordates

  1. Lancelets

    1. Retain chordate characteristics as adults

  2. Sea Squirts (tunicates)

    1. larva has chordate characteristics

    2. Adults are sessile

Vertebrates

  1. Fishes-make up most vertebrates

  2. Amphibians

  3. Reptiles

  4. Birds

  5. mammals

Vertebrates

  • Notochord replaced by vertebral column in most

  • Cranium encloses brain

    • Endoskeleton (cartilage or bone) protects nervous system and support body

  • Extensive cephalization

  • Efficient circulatory, respiratory, excretory systems

  • Efficient circulatory, respiratory, excretory systems

    Jawless Fish (Agnathans)

  • Hagfishes, lampreys