Vertebrates

1
Vertebrates

• A subphylum of Phylum Chordata

2
Characteristics of Chordata

• Bilateral deuterostomes that have a notochord (or
  verterbral column), pharyngeal slits, a muscular,
  post anal tail.

3
Non-Vertebrate Chrodates

• Tunicates- resemble other chordates only during
  their larval stage. Once they settle in they
  lose their chordata characteristics
• Lancelets- swim to the bottom of the ocean floor
  and dig in backwards and filter feed.
• Hagfish- have a skull made of cartilage, but
  dont have jaws or vertebrate. They are filter
  feeders that excrete slime that repulse other
  scavengers. If attacked, they can excrete
  several L of slime in a few minuites. They are
  not really fish.

4
ChondrichthyansSharks and Rays

• Skeleton made of cartilage, often impregnated
  with calcium.
• They have very acute senses for hunting.
• All fertilizatin occurs internally. Can be
  oviparous (lay eggs), or ovoviviparos(retain eggs
  in the oviduct) and a few are viviparous(live
  birth)
• Reproductive, digestive system, and excretory
  system all end in a cloaca
• Have a lateral line system that detects
  vibrations in the water
• Maintain buoyancy by storing oil in the liver,
  but must continue swimming to stay afloat, and
  move water over the gills.
• Scales are tooth like, and decrease drag.

5
OsteicthyesRay finned and lobe finned

• Exchange gases by drawing water over their gills
  that are covered by an operculum that pumps water
  over the gills
• Most have a swim bladder that increases buoyancy
• Flattened boney scales cover the body and covered
  with mucous
• Have a 2 chambered heart
• Have a lateral line system
• Most are oviparous with external fertilization
• Ray finned fish named for flexible rays in fin.
  Tuna is an example.
• Lobe finned fish have lobe fins made of rod
  shaped bones.

6
Amphibians

• Amphibian means 2 lives aquatic and terrestrial
• In the aquatic stage resemble fish.
• In the adult stage they develop lungs, legs,
  external ear drums.
• Some lack lungs and breath through the skin that
  must remain moist.
• Have external fertilization in moist environments
  because their eggs dehydrate quickly.
• Have a 3 chambered heart

7
Reptiles

• Have scales that contain keratin. This creates a
  waterproof barrier that prevents dehydration, but
  stops them from being able to breath through skin
  so they completely rely on lungs (except turtles
  who also use the cloaca)
• Use internal fertilization and lay amnioic eggs
  with a leathery shell that wont dehydrate, and
  allows the offspring to grow larger
• Most are ectothermic (cold blooded) but evidence
  has shown that some dinosaurs were warm-blooded.
• 3 chambered heart that has partial seperation in
  the ventricels

8
Aves

• Feathered
• Endothremic with a 4 chambered heart
• Very high metabolism
• Amniotic eggs
• Bones are honeycombed, lack teeth, and have
  modified organs such as the gizzard to minimize
  weight.
• Lungs are modified to increase the amount of
  oxygen that can be absorbed. They have air sacs
  that collect air, so that air flow is constantly
  in one direction.

9
Mammals

• Mammary Galnds
• Hair
• Endothermic with a 4 chambered heart
• Larger brains
• Many different feeding adaptations
• Monoterms (egg laying)
• Marsupilals (give birth to early undeveloped
  offsping that finish development in a pouch
  attached to a nipple,
• etherian (placental mammals that give birth to
  developed offspring)