Overview of Vertebrates
Kingdom Animalia
Phylum Chordata (Lancelets, tunicates)
Sub-Phylum Vertebrata
Class Myxini
Class Cephalaspidomorphi
Class Chondrichthyes
Class Osteichthyes
Class Amphibia
Class Reptilia
Class Aves
Class Mammalia
Classes of Vertebrates
Class Myxini
Class Cephalaspidomorphi
Class Chondrichthyes
Class Osteichthyes
Class Amphibia
Class Reptilia
Class Aves
Class Mammalia
Chordates
At some point during development, members of this phylum MUST
exhibit these characteristics:
1.
Basic Characteristics:
Notochord: develops into the skeleton
2.
Pharyngeal Pouches (Gill slits): develops into gills in
aquatic vertebrates; jaws/inner ear/nostrils in terrestrial
vertebrates
3.
Dorsal Nerve cord: develops into the spinal cord and brain
4.
Post-anal tail: can contain bone and muscle
5.
Ancestral thyroid gland: regulates metabolism, growth and
development
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Non-vertebrate Chordates
2 Sub-Phyla: Tunicates and Lancelets (aquatic)
Tunicates (sea squirts): 1,250 species
Lancelets: 23 species
Fish
Characteristics:
Aquatic Vertebrates exhibit:
1. Paired fins
2. Scales
3. Gills (most)
4. 2 Chambered Heart:
1 atrium & 1 ventricle
5. Carnivores, herbivores,
omnivores, parasites, filter feeders
Lungfish
Live in Australia, Africa, South America
These areas have wet and dry seasons
During dry season
1) They burrow into mud
2) Secrete slime that mixes with mud to create
cocoon
3) Gulps air
Fish
Class Myxini and Cephalaspidomorphi:
“Jawless Fish” - NO JAWS!
Characteristics:
1. Eel shaped body
2. Cartilaginous skeleton
3. No fins or jaws
4. Filter Feeders/Parasites
5. Examples
Myxini: Hagfish
Cephalaspidomorphi: Lamprey
Hagfish
Lamprey
Fish
Class Chondrichthyes:
“Cartilage Fish”
Basic Characteristics:
1. Skeleton made of cartilage
2. Placoid scales
3. Jaws present
4. Examples: sharks, skates, rays
Caribbean Reef Shark
Great White caught off shore of Ragland, NZ
Whale Shark
Bull Shark
Eagle Ray
Blue Spotted Ray
Skates
Lay eggs in Mermaid’s
purse
Do not have barbed tails
Only saltwater
Rays
Live birth
Barbed tails
Fresh and salt water
Fish
Class Osteichthyes:
“Bony Fish”
Basic Characteristics:
1. Skeleton made of bone
2. Skin with scales
3. Jaws present
4. Examples: Bass, Perch, Tuna…..
Coelacanth
Thought to be extinct
for 70 million years
Found near Comoro
Islands (north of
Madagascar) in 1938
Since then, fisherman
occasionally catch
them at great depths
Can’t keep them alive
more than a few hours
after capture
Class Amphibia
1.
Basic Characteristics:
Smooth, moist skin with NUMEROUS mucus glands
2.
Gills, lungs – pulmonary respiration
Skin - cutaneous respiration
3.
Lacks scales and claws
4.
Rely upon water for reproduction
Metamorphosis:
Larval stage – aquatic; Adult - terrestrial
Larvae: 2 chambered heart
Adults: 3 chambered heart
5.
Examples: Salamanders, Toads, Frogs, Caecilians, Newt
Coqui
Bullfrog
Newt
salamander
Caecilian
Poison Dart Frog
Frog
External Anatomy:
Tympanum – ear drum
Nictitating membrane – protective eyelid
Frog
Internal Anatomy
Cloaca –
removal
of waste
and
gametes
Amphibian Reproduction
Amphibians must lay their eggs
in water since the eggs lack a
protective outer membrane
External fertilization and
development for most
amphibians.
Metamorphosis
Class Reptilia
1.
2.
3.
4.
5.
6.
7.
Basic Characteristics:
Dry, scaly skin
Like Humans!
Amniotic egg
Internal fertilization
Some with claws and limbs
3 chambered heart: 2 atria, 1 ventricle or 4
chambered heart (crocodiles and alligators)
Ectothermic (cold-blooded)
Respiration through lungs only
Examples: snakes, lizards, tuatara, turtles, alligators
Monitor lizard
Milk snake
Iguana
Sea turtle
Gecko
Iguana
Chameleon
Crocodiles/Alligators:
Eyes & nostrils are arranged on top of head
allowing them to breathe and see
Turtles:
Shell parts - Carapace: dorsal; Plastron: ventral
Reptiles
Snakes:
* Jacobson’s organ - detects food through scents
* Infrared sensors in pit (pit vipers)- detect heat
* Venom:
1) Hemotoxin (attack circulatory system)
2) Neurotoxin (attacks nervous system)
* No ear openings or eye-lids. Use ventral side of
body for sensory info.
Tuatara
Reproduction
Internal fertilization: sperm injected via the
cloaca
Most reptiles lay eggs
- Oviparous: lay eggs
- Ovoviviparous: eggs stay in body after
internal fertilization and are born alive
- Viviparous: give live birth (rattlesnakes, garter
snakes)
45% of skinks are ovoviviparous
Reptilian Egg
Blanding’s Turtle
(Nova Scotia)
Class Aves: Birds
1.
2.
3.
4.
5.
6.
7.
8.
9.
Basic Characteristics:
Feathers: contour (flight) and downy (insulation)
Endothermic (warm-blooded)
Beaks and no teeth
Skeleton is made of hollow bones
4 Chambered heart
Claws and scales on feet
Amniotic egg encased with calcium
Parental care (most species) and nest building
Classify birds based on colorations, flight patterns,
calls, nests, etc.
Peregrine falcon
African gray parrot
Great horned owl
Blue heron
Peahen and
peacock
Bird’s feathers
Archaeopteryx – earliest bird
(had reptilian and bird –like
characteristics
Internal Anatomy of Birds
Digestion: crop and gizzard
Waste product - uric acid
Class Mammalia
1.
2.
3.
4.
5.
Basic Characteristics
Hair or fur
Female’s possess mammary glands
4 chambered heart
Endothermic
3 groups of mammals: monotremes,
marsupials, and placentals
Monotremes
1. Oviparous: Lay eggs
2. Female incubates eggs once laid
3. Examples: Duck billed platypus and
Spiny Anteater (Echidna)
Marsupials
1. Viviparous
2. Young complete
development inside pouch
3. Examples: kangaroo,
koala, opossum, wallabee
Albino wallabee in pouch
Placentals
1.
2.
3.
4.
Viviparous
Young are nourished by a placenta
95% of all mammals
Gestation: period of time in which
young develops in mother’s uterus
(ex. 22 months for elephant, 21 days for mouse)
5. Diverse group: land, air, water