phylum chordata (the chordates). what is a chordate? classification: kingdom animalia, phylum...
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Phylum Chordata (The Chordates)
What is a chordate?• Classification: Kingdom Animalia,
Phylum Chordata• Four Phylum Characteristics
• Notochord: supportive rod (replaced by cartilage or bone in vertebrates)
• Tubular nerve cord: single, dorsal; anterior end enlarged into brain (develops into brain and spinal chord in higher vertebrates)
• Pharyngeal gill slits/pouches/folds (controversial) mostly embryonic in higher vertebrates
• Post anal tail: generally supported by notochord or vertebral column • provides method of locomotion in aquatic chordates• present in humans as coccyx; in most other mammals as
wagging tail.
Chordate Anatomy
Invertebrate Chordates (NO vertebrae): Sea Squirts or Tunicates
Lancelet
What is a vertebrate?
Characteristics:
•Animals with a backbone or vertebral column (endoskeleton)
•Presence of a Spinal Cord - dorsal, hollow nerve cord
•Anterior end of spinal cord develops a brain
Vertebrate Classes
• Class Agnatha: Jawless Fish (lamprey, hagfish)• Class Chondrichthyes Cartilage Fish (sharks,
rays, skates, catfish…)• Class Osteichthyes: Bony Fish (salmon, bass,
goldfish, etc…)• Class Amphibia: Amphibians (frogs,
salamanders…)• Class Reptilia: Reptiles (lizards, turtles…)• Class Aves: Birds (sparrows, hawks…)• Class Mammalia: Mammals (humans, whales,
cats…)
What are Fish?* Anything with gills, scales, and fins…
TYPES OF FISH
Jawless fish (Agnatha): lamprey and hagfish
•Lamprey is a parasite, it attaches to other fish and sucks their blood
•Hagfish is a scavenger, it lives in the ocean and is known for its slimy secretions
Cartilage Fish
•Kingdom Animalia, •Phylum Chordata, •Subphylum Vertebrata•CLASS CHONDRICHTHYES
Sharks and Rays
SHARKS
*The pectoral fins of sharks do not move* Sharks do not have an operculum or a swim bladder*sharks will sink if they stop swimming
BONY FISH
•Class OSTEICHTHYES•Bony skeleton•75% of vertebrates•Most have swim bladder to regulate density•Operculum = bone covering the gills•Two chambered heart
External Anatomy: Bony Fish
Coelacanth: living fossil, lobe-finned
Clown Fish (Nemo)
Kissing Fish…Awww…
Other Vertebrate ClassesClass Amphibia: Amphibians
• Live in and out of water• Need water for soft skin and for
reproduction (external fertilization)• Respiration by gills, lungs, and skin• 3-chambered heart: 2 atria, 1
ventricle• Poikilotherms
Amphibian Groups
Kingdom AnimaliaPhylum ChordataSubphylum VertebrataClass Amphibia
3 Orders:Order Urodela (Salamander/Newts)Order Anura (Frogs/Toads)Order Apoda (Cecilians)
METAMORPHOSIS• Series of changes that occur as an
organism grows
Feeding• Larva (tadpoles) are usually herbivores• Adults are usually carnivores
Respiration• Larva (tadpoles) breath with gills• Adult frogs have lungs
Some amphibians keep gills all their life, mudpuppy
See videos at
http://video.nationalgeographic.com/video/player/animals/index.html
Class Reptilia: Reptiles
• Link between sea and land??• Adapted to land:
– Dry scaly skin- aids in conserving moisture– Internal fertilization- improves egg survival– Amniotic egg- embryo enclosed in fluid-filled sac covered
by shell– Lungs for gas exchange– Excretes uric acid - insoluble solid, nitrogenous waste– Poikilotherm– 3-chambered heart: 2 atria, partly divided ventricle
(exception: alligators have 4)
Types of Reptiles
4 Main Groups (ORDERS) Crocodilia = crocodiles, alligators Testudines = turtles and tortoises Sphenodonta = tuatara Squamata = lizards, snakes ( largest group )
Order Sphenodonta
Only found in New Zealand, they have no external ears and a 3rd eye
Order Testudines
Tortoises usually live on the land, turtles in the water
Snapping turtles can be very aggressive
The top of a turtle's shell is the carapace, the bottom is the plastron
Is this a turtle or a tortoise?
Order Crocodilia
*Ornithology is the study of birds
Classification
Kingdom Animalia---Phylum Chordata------Subphylum Vertebrata---------Class Aves
Aviation = flight
Characteristics
1. Forelimbs modified into wings 2. Feathers 3. Hollow, lightweight bones 4. Endothermic (a.k.a. Homeotherm)5. Efficient respiration 6. Heart with a completely divided ventricle (4 chambers) 7. Scaley feet (birds are related to reptiles) 8. Furculum (wishbone)
Types of Feathers
Down feathers - provide insulation* birds are endothermic (homeotherms)
Contour feathers - cover head and body, provide coloration
Flight feathers - on wings and tail, provide lift