Transcript Phylum Chordate

Phylum Chordata
--Vertebrate chordates:
fishes, amphibians,
reptiles, birds, mammals
--Invertebrate chordates:
tunicates and lancelets
Characteristics
(embryonic development)
Dorsal hollow nerve cord
Notochord—firm flexible
supporting rod located just
below the nerve cord
Gill slits—paired opening along
the pharynx
Post anal tail…extends beyond
the anus
Endothermic
Warm blooded..temp is
controlled by internal
processes
Ectothermic
Cold blooded..temp is
regulated by external
environment
Three Subphylums
1. Urochordata
--tunicates (sea
squirts)
--most adults are
sessile, squirt
water when
disturbed
2. Cephalochordata
Lancelets
Can swim but prefer to stay
buried in the sand
Filter feeders
3. Vertebrata (humans)
Animals with backbones
Dorsal hollow nerve cord becomes
the spinal cord and brain
Notochord is the backbone
Gill slits become other breathing
organs
Tails are kept in most vertebrate
animals
Six Classes
1. Agnatha
--no jaw (jawless fish)
--skeleton made of cartilage
--snake-like body without
paired fins (not good
swimmers)
Examples
Lampreys—attach to other fish
using their round mouth and its
rasping parts (parasites)
Hagfish—scavengers,
move slowing through
cold water using
tentacles to locate
dead and dying fish
Hagfish
Have you ever gone fishing?
Tell me about your experience.
OR
Pick your favorite fish and
describe it. Why do you like it.
2. Chondrichthyes
Sharks, skates, rays
General characteristics
Skeleton mostly made of
cartilage
Have scales made of dentin
Excellent sense of smell
Lateral line picks up vibrations
Sharks—torpedo shape body
fertilization is internal and the
eggs develop internally
Young sharks are called pups
Must keep moving to keep
water flowing through gills
Oily liver helps buoyancy
Skates and Rays—basically
benthic (bottom) lie and wait
animals
Have a tail which can cause
pain
Pectoral fins are expanded and
they look like they are gliding in
the water
3. Osteichthyes
Characteristics
Bony skeleton—bony fishes
Swim bladder
Scales
Paired fins
Operculum flap covering gills
2 chambered heart
kidneys
Page 608…Read the life cycle
section
Using complete sentences,
explain the life cycle of a frog
Compare and contrast the
animals in the class
chondrichthyes to the animals
in the class osteichthyes.
4. Amphibians
frogs, salamanders, toads,
caecilians
Spend part of their life in the
water and part living on land
Tadpole  Frog
Frogs
Have a nictitating membrane
over their eye…keeps eye
moist in air and protects in the
water
Hear through a tympanic
membrane (detect sound
through air and water
Digestive System
Path of food  Mouth,
esophagus, stomach, small
intestine, large intestine, cloaca
Undigested food along with
products from the excretory
system and reproductive
system empty into the cloaca
Respiratory
Breathe using lungs
Diffuse oxygen through skin
(must stay moist)
Tadpoles have gills for gas
exchange
Circulation
Double loop circulation
Three chambered heart
Deoxygenated blood flows to the
heart, then it is pumped to the
lungs where it is oxygenated,
then it flows back the heart to be
pumped to the rest of the body
Page 608
Metamorphosis
Frogs are the only amphibian to
go through this process
Egg
Tadpole…tail, gills, lives in
water
Frog…no tail,lungs,has legs,
lives on land
A froggie eats bugs. Tell me the
pathway that the bugs will travel
as they go from the froggie’s
mouth to its anus.
Look at the five pictures on page
804
List some adaptations that you
see for these reptiles.
Must have at least 5
5. Reptiles
Ectothermic
Egg-laying..soft, leathery shells
Scaly dry skin..adaptable to life
on land
Internal fertilization
Breathe with lungs
Endoskeleton
3-chambered heart except
crocodilians
Kidneys remove wastes and
absorb most of the water
Shed skin
Eggs are called Amniotic eggs b/c
they have a fluid filled amnion sac
which surrounds the embryo
6. Aves
Feathers
Contour feathers—have a stiff
central barb
Down feathers—short shafts,
for insulation
Oil gland at base of
feather..waterproof
Wing flow
Bones are hollow to reduce
density
Fused collarbone and
vertebra…furcula
4-chambered heart
Endothermic (warm blooded)
High metabolism (eat a lot!)
Digestive system..crop
(storage), gizzard
(grinding…often contains
stones)
Unique respiratory
system
Anterior and
posterior air sacs
in addition to
lungs
Air flows in air
sacs in only one
direction (pg
810)
Excretion..no urinary bladder
Special glands around the
eyes remove excess salts
7. Mammals
Mammary glands..produce milk
to nurse young
Fur or hair
Endothermic
Well developed brains
Internal fertilization…live birth
Breathe with lungs
Contain air sacs
Diaphragm..muscle under
lungs which helps breathing
Examples…
• Monotremes: mammal that
lays eggs (duck-billed
platypus
• Marsupials: Kangaroo..give
birth to small immature young
that further develop inside
mom’s pouch (Pg 829)
• Placental: young develops
more fully before birth
Placenta..organ attached to
mom and fetus
Mammalian Teeth
Page 823
Orders of Placental Mammals
Page 830