BIOL-Q 201 Lecture Notes - Lecture 10: Gill Slit, Fish Scale, Chondrichthyes
Document Summary
Vertebrate animals: phylum chordata: the chordate animals, four key characteristics of chordates. Notochord: flexible, longitudinal rod located between the digestive tract and the nerve cord. Gill structures are present in the pharynx: pharynx = region of the digestive tube just behind the mouth. A post anal tail (e. g. , a tail posterior to the anus: the invertebrate chordates (tunicates and lancelets) Characteristics of tunicates: adult tunicates: (left, adhere to rocks and boats, no notochord, nerve chord, or tail, have a huge gill apparatus. Each white, vertical line surrounds a gill slit: filter feeders, tunicate larvae: (right), swimming, tadpole-like, have all 4 chordate characteristics. Characteristics of lancelets: have all 4 chordate characteristics, feed on suspended particles, food is trapped by gill apparatus. Water enters gill apparatus; exits in rear: the vertebrate chordates. Characteristics of vertebrates: skull, backbone composed of vertebrae, skeletal elements that support the body, most have hinged jaws, i. jawless fishes: class agnatha: hagfish and lamprey eels.
