Bionotes - Lecture notes 6 PDF

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Notes from one of the lectues (I think the sixth week)...

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Deutorozomes: Echinodermata, Chordata Echinodermata: - characteristics triploblastic true coelomate, deutorozome dioecious larvae are bilaterally symmetric, adults show radial or 5parted symmetry, with no cephalization Water vascular system - unique to this group ring canal, radial canals, ampullae and tube feet. Spiny Skin Gills, spines, pedicellariae- pincer-like structures. Echinoderm taxonomy: 6 classes class asteroidea starfish or sea stars Class ophiuroidea Brittle stars Echinoidia Crinoidea sea lilies/sessile Holothuroidea sea cucumbers Concentricycloidea sea daisies recently discovered Chordata One lineage of vertebrates colonized land 365 million years ago 52,000 species of vertebrates, including the largest ones ever Vertebrates have hella diversity Derived Characteristics: Nodalchord, Dorsal, hollow nerve cord, pharyngeal slits or cleft, Muscular, post-anal tail Notochord Notochord is hard to fine Dorsal, hollow nerve cord develops into the central nervous system pharyngeal slits or clefts - suspension-feeding in invertevrate chordates, gas exchange in vertebrates, develop into parts of ear, head, and neck in tetrapods Muscular, post-anal tail, propels if aquatic 3 subphyal: Urochordata, Cephalochordata, Vertebrata First two are invertabrate chordates Lancelets: invertebrate chordate (cephalochordata) Tunicates: Urochordata, filter feeders, attatch to substrate, larvae can swim Vertebrates: craniates, STUDY THE TAXONOMIC KEY ON CANVAS

Hagfishes: basal group of craniates, myxini, bottom-feeders Lamprey: petromyzontida. jawless vertebrates that feed by clamping their mouth onto a live fish -exoparasite Origions of bones an teeth. Jawed vertebrates, gnathostomes outnumber jawless vertebrates. Derived characters of Gnathosomes: Jaws, developed from anterior pharyngial gill slits forebrain associated with enhanced smell and vision, lateral line system - sensitive to vibrations Chondrichtyes: sharks, stingrays, spotted rattfish Bony fishes: all fishes except sharks rays and Something sarcopterygii: lobe-fin fishes - muscular pelvic and.. missing. believe they are the predecessor to amphibians coelachant was thought to be extinct for long time but we just found a bunch of them. class actinopterygii swim bladder, control buoyancy, have vocolation from the swim bladder ray-finned fishes...