Download Introduction to Phylum Chordata

Introduction to Phylum Chordata
Includes 3 subphylum:
1) Urochordata, the tunicates
2) Cephalochordata, the lancelets
3) Vertebrata, the vertebrates
Phylum Chordata
• To be classified as a chordate, an animal must
have 4 key characteristics:
1. Dorsal, hollow nerve cord
 Develops from the ectoderm
2. Notochord
 Long supporting rod
 Develops in the backbone in vertebrate chordates
3. Pharyngeal pouches
 Slits develop into gills or pharynx
4. Tail extends beyond the anus
Subphylum Urochordata
• These are invertebrates
– Do not have a backbone but have a notochord
• These include tunicates (sea squirts).
– Soft-bodied marine organisms
– Filter-feeders
Subphylum Cephalochordata
• These are invertebrates
• This subphylum includes the lancelets
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Live on sandy ocean bottom
Filter-feeders
Defined head region and a mouth
Closed circulatory system; no true heart
Fishlike motion
Subphylum Vertebrata
• Notochord is replaced with a backbone or
vertebrae – bone or cartilage that surround
and protect the nerve cord.
• Includes sharks, bony fishes, amphibians,
birds, and mammals
Stop for Animal Activity
Subphylum Vertebrata Notes
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Class Agnatha: Jawless
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Lack true jaws
Snakelike bodies
Skeleton of cartilage
Smooth skin with scales
Ectothermic and oviparous
Includes Lampreys and Hagfish
Class Agnatha: Lamprey
Class Agnatha: Lamprey
Class Agnatha: Hagfish
Class Agnatha: Hagfish
Class Chondrichthyes: Cartilaginous
Fishes
• Skeleton made of cartilage
• Hinged jaw, paired fins, toothlike scales cover
body
• Ectothermic
• Some are oviparous, most are ovoviviparous
• Includes sharks, rays, and skates
Class Chondrichthyes: Sawfish
Class Chondrichthyes: Blue-spotted
Ray
Class Chondrichthyes: Brown shark
Class Chondrichthyes: Whale shark
Class Osteichthyes: Bony Fishes
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Skeleton of bone
Hinged jaws, paired fins
Overlapping scales
Air bladder
Ectothermic
Oviparous
Including salmon, trout, perch, carp and eels
Class Osteichthyes: Hippo tang
Osteichthyes: Lungfish
Osteichthyes: Common Dolphifish
Osteichthyes: Yellow perch
Class Amphibia: Soft eggs
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Moist thin skin, No scales
Four limbs
If present, feet lack claws are often webbed
Most undergo metamorphosis
Most use gills, lungs and skin for respiration
3-chambered heart
Oviparous: eggs most remain moist
Ectothermic
Class Amphibia: Tadpole
Class Amphibia: Eastern Tiger
salamander
Class Amphibia: Northern Cricket Frog
Class Amphibia: Green Climbing Toad
Class Reptilia: Amniotic egg
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Dry skin and a scale covered body
Four limbs (except snakes)
Live and reproduce on land
Amniotic eggs (eggs that contain layers of
specialized membranes)
• Lungs and a 3-chambered heart with a partially
divided ventricle
• Ectothermic
• Most are oviparous but some are ovoviviparous
(python snakes and garter snakes)
Class Reptilia: Black Mamba
Class Reptilia: Komodo Dragon
Class Reptilia: Albino Chinese Softshelled turtle
Class Reptilia: American Crocodile
Class Reptilia: American Alligator
Class Aves: Wings/Feathers
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Birds that have wings and feathers
Feathers are essential for flight and insulation
Forelimbs are modified into pair of wings
Lightweight rigid skeleton
Endothermic; rapid metabolism allows for flight
Lungs associated with air sacs
All oviparous
4-chambered heart needed for flight
Class Aves: Ostrich
Class Mammalia: Produce milk
• Placental development and mammary glands
that produce milk
• Hair or fur
• Endothermic
• 4 chambered heart
• Most are viviparous
Class Mammalia: Platypus
Class Mammalia: Vampire bat
Class Mammalia: Sperm whale
Class Mammalia: White-tailed Deer
(fawn)