Biology 202 - Lab 8

  1. orders of class amphibia
    • Caudata: salimanders
    • Anura: frogs
    • Gymnophiona: (caecilians which are limbless, burrowing and almost blind)
  2. orders of class reptilia
    • Testudina: turtels
    • Crocadylia: crocs gravials caimans, and alligators)
    • Sphenodontida: the tuatara
    • Squamata: lixards and snakes
  3. Integument amphibia
    • frogs have thin skin with no scales or keratin and are vulnerable to dessication (not the austrailian burrow frog)
    • some species facilitate gas exchange via cutaneous respiration
  4. Integument Reptilia
    • reptile skins is dry and covered by scales
    • formed by a deposit of keratin within the epidermis
    • turtles shell: 59 different dermal bony plates. top shell (carapace) has bony skutes which help identify species
  5. support and locomotion
    • frog larvae: have fusiform body and a laterally compressed tail for swimming
    • adult frogs: have a thinner light weight skull and jointed limbs

    reptile locomotion: many forms(slithering swimming flight) so generalizations are hard
  6. amphibian food aquisition and digestion
    • amphibian diet is broad but mainley invertebrates. larvae are aminly herbivores. adults locate prey by sight and employ sit and wait strategy.
    • salamanders and caecilians rely heavily on olfaction for prey detection\
    • tongue is specialized: attateched at anterior margin of jaw and folds over the floor of the mouth
  7. Respiration
    • developed lungs that draw in air for gas exchange
    • lungs specialized via vascular folding of lung lining but some do gas exchange across their sckin that may be highly folded too
  8. Circulation
    • developed double circulation
    • pulmonary circuit: blood to the lungs
    • Systemic circuit: blood to the body
    • have a 3-4 chambed heart for this rather than 2 hearts as it reduces energy usage
    • frogs ventricle is undivided but spiral valves sends low O blood to the lungs and high O blood to the body
    • when under water a muscular sphincter reduces blood flow to the lungs
  9. Excrition
    • amphibians evolved from fresh water fish so they have an opisthonephric kidney
    • this eliminates excess water thus constraining frogs from dry places (when hot they ca get water from dew drops and pools)
    • some aestivate (dormant) during dry season and only come out during short wet season for mating and feeding
  10. Sensory abilities
    • skin of amphibians sensitive to heat cold and pain
    • larval amphibians have lateral line system (some adults too)
    • rely on chemo reception: located in nasal epithelium, on skin, mouth, and tongue
    • olfaction important for mate recognition, detection of noxious gases, and prey capture.
    • they use sight for prey recognition so have large specialized eyes and large optic lobe.
    • ears consist of: tympanic membrane, middle ear, and inner ear to reaceive a range of frequencies
    • frog song important for mate location and attraction
  11. Reproduction
    • amphibians
    • eggs lack shells (restricts eggs to aquatic environment) and respiration occurs accross a thin outer membrane.
    • anurans lay eggs in ponds and caudates lay eggs in damp sites
    • tropic frogs have pouches
    • reptile eggs are amniotic as they have a shell and 3 extra embryonic membranes so they can developin their own environment
    • Amnion: fluid filled and surrounds embryo. provides protection from dessication and shock
    • Chorion and Allantois: vascularized for efficient gas exchange
    • allantois also stores waste from embryo
Card Set
Biology 202 - Lab 8
Classes amphibia and reptilia