Transcript Chordates powerpoint 2012

Chordates
NonVertebrate Chordates, Fish,
Amphibians, Reptiles and Mammals
General Chordate Characteristics
• At some stage of development, all
vertebrates share the four
features:
1. Notochord-long supportive rod
that runs through the body, most
only have it while embryos
2. Dorsal hollow nerve cord-nerves
branch from this cord and
connects to internal organs,
muscles and sense organs
3. Pharyngeal gill slits-paired
structures in the throat region, in
some develop gills
4. Tails-can contain bone and muscle,
used for swimming in some adult
species.
tail
hollow nerve cord
notochord
pharyngeal slits
Endoskeleton
• Internal skeleton
• Made of either bone or cartilage
• Grows with the body, allows vertebrates to
grow to large sizes
• Most have a strong supporting structure
known as the vertebral column, or backbone
• The vertebrae enclose and protect the spinal
cord.
Control of Body Temperature
• Endotherms- use metabolic
heat to keep tissues warm
– Live in a wider range of
climates than ectotherms.
• Ectotherms-regulate body
temperature by
surrounding envrionment.
Development
• Bilateral symmetry
• Deuterostome
• Coelomate
Nonvertebrate Chordates
• Tunicates-closest relatives
to vertebrates
– Filter feeders, mobile
larvae, sessile adults
• Lancelets- small fishlike
creature that is mobile
from larval to adult form
-keep all four structures from
birth through adulthood
Jawless Fish, Agnatha
• Body temp regulation:
Ectothermic (all fish exist in
homeostasis at the same
temperature as their
surroundings)
• Skin/body: skin covering the
body, no scales, no fins or limbs,
no jaws, eel-like body with
compressed caudal fin.
• Skeleton: cartilaginous
endoskeleton
• Feeding: carnivores, parasites
and scavengers
• Respiration: gills
• Circulation: open circulatory
system
Gills are shown above
• Excretion: ammonia waste
released through the gills into
the surrounding water
– Solid waste is excreted through
cloaca (a orifice that combines
the urinary, digestive, and
reproductive tracts)
• Reproduction: hermaphroditic,
external fertilization
• Sense organs: lateral line that is
used to detect movements and
vibrations in surroundings
• Examples: hagfish and lampreys
Cartilaginous Fish, Chondroicthyes
• Body temp. regulation:
Ectothermic
• Skin/body: Denticles (tooth-like
scales covering the skin), paired
fins, mouth with several rows of
triangular teeth, large caudal fin
• Skeleton: cartilaginous
endoskeleton.
• Feeding: carnivores (predators)
and filter feeders.
• respiration: gills
• Circulation: Closed system, 2chambered heart pumps blood
around the body in a single loop
system.
• Excretion: kidneys filter
wastes from blood and
conserve water loss during
excretion
• Solid waste is expelled
through cloaca.
• Reproduction:are
Viviparous (embryos stay in
the mother’s body after
internal fertilization and
young are born alive)
• Sense organs: lateral line
• Examples- Sharks and rays
Bony Fish, Osteoicthyes
• Body temp regulation:
Ectothermic
• Body/Skin: broad flat scales and
skin that secretes mucous to
reduce friction while fish swim,
paired fins made of rays/spines
(ray fins) and fins with out
rays/spines (lobed fin)
• Skeleton: bone.
• Feeding: as predators,
scavengers, detrivores, and filter
feeders.
• Respiration: gills (have an
operculum to regulate water over
gills)
• Circulation: 2 chambered heart, (1 way
circulation) countercurrent flow of the
movement of water against the flow of
blood in the fish’s gills.
• Excretion: kidneys filter wastes and
prevent water loss during excretion
• Solid waste is expelled through
cloaca.
• Reproduction: species determine
internal/external fertilization, most are
oviparous (external fertilization) (eggs
hatch outside the mother’s body) some
are ovoviviparous(eggs stay in mother’s
body after internal fertilization, develop
inside egg and are born alive)
• Sense organs: lateral line system
• Presence of swim bladder to
help maintain buoyancy
• Transitional species: lobed
fin fish thought to be the
precursor to amphibians.
• Examples: Guppies, Salmon,
angelfish, goldfish, perch
Amphibians
• Body temp regulation:
Ecothermic
• Skin/body: They have
smooth moist skin.
Internal skeleton is
made of bone. (large
shoulders and hip
bones allowed
movement from water
to land)
• Tympanic membranedetect sound vibrations
(copy down on your
sheet!)
• Feeding: Carnivores and
insectivores
• Respiration: larva
diffusion through skin
and gills, adults poorly
developed lungs also
rely on skin
Amphibians
• Circulation: 3 chambered
heart that is composed of
2 atria and 1 ventricle,
double loop system
• Excretion: Kidneys filter
liquid waste and it is
released from the
bladder, solid waste is
removed through the
cloaca .
• Reproduction: is mainly
external, with the
exception of caecilians
which is internal
– Must release eggs
(through cloaca) in a
moist environment
(some lay directly in
water, other moist
ground, or in sacs on the
female’s back
• Amphibians start life
cycle under water and
move to land at adult
hood. (Double life)
– May go through
metamorphosis
• Examples: toads, frogs,
salamanders and
caecilians
Reptiles
• Body temp regulation:
Ecothermic
• Skin/body: Dry scales,
toes with claws, body
plan better adapted to
living on land
• Skeleton: bone
• Feeding: Carnivores and
herbivores.
• Respiration: Lungs are
spongy, allows for more
gas exchange. Most
reptiles have 2, snakes
only have 1 lung.
• Circulatory: Have a double
loop. Non Crocodilian have
a 3 chambered heart.
Crocodilian reptiles have a
4 chambered heart.
• Excretion: Kidneys,
bladder and cloaca are
used to eliminate waste.
Typical reptile
crocodile
• Reproduction:
Fertilization is internal
and first animals to use
an amniotic egg for
offspring, may have
oviparous birth (eggs
deposited into an
external nest) or
viviparous (reptile
retains egg and gives
birth to live offspring)
Amniotic Egg
• Amniotic eggs have a
tough shell that is
almost completely
waterproof, and
contains all the
developing embryo
needs until it is ready to
break free from shell.
Reptiles
• Examples include:
Snakes, lizards, turtles,
alligators, and
crocodiles
Aves
• Body Temp Regulation:
Endothermic
• Body/Skin: Feathers and dry
scales cover the body, horned
beak, no teeth, rearranged
muscle in hips and legs,
forelimbs are wings
• Skeleton: hollow bone, fused
collarbones that form v-shape
wishbone
• Feeding: Carnivores,
Insectivores, Herbivores,
Nectivores
• Respiration: Lungs with air
sacs, allows for more efficient
oxygen exchange with
unidirectional flow.
Aves
• Circulation: Have a 4
chambered heart composed
of 2 atria and 2 ventricles.
• Excretion: Kidneys and cloaca
are used to eliminate waste.
Birds do not urinate (with the
exception of the ostrich).
• Reproduction: Fertilization is
internal and use an amniotic
egg with a hard shell for
offspring, Have oviparous
birth (eggs deposited into an
external nest).
Aves
• Examples include:
extinct archeopteryx,
hummingbird, green
woodpecker, bluefooted booby, bald
eagle
blue-footed booby
green woodpecker
Bald eagle
Mammals
• Body temp regulation:
Endothermic
• Skin/body: Hair covers
the body, have middle ear
bones to detect sound
• Skeleton: made of bone
• Feeding: Carnivores,
Omnivores, and
Herbivores
• Respiration: Lungs are
spongy, allows for more
gas exchange. All
mammals have 2
Mammals
• Circulatory system: Have a 4
chambered heart composed of
2 atria and 2 ventricles.
• Excretion: Kidneys, bladder,
anus and sweat glands (not all
mammals) are used to
eliminate waste.
• Reproduction: Fertilization is
internal. However, mammals
are classified differently
depending on how they give
birth.
• Most have sweat (used also to
eliminate heat) and sebaceous
(fat secreting) glands
• Produce milk to nourish
young, using mammary glands
Placental Mammals
• All bear live young,
which are nourished by
placenta (a specialized
embryonic organ
attached to the uterus
wall) before birth in the
mother's uterus
Placental Mammals
• Examples include:
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Humans
Dolphins
Field mice
Badgers
Marsupial Mammals
• No placenta.
• After 4-5 wks., young
emerge from the birth canal
in an extremely
undeveloped state.
• Immediately after birth, the
tiny offspring, crawls along
its mother’s body and
finishes developing
attached to a nipple located
inside the mother’s pouch.
Marsupial Mammals
• Examples include:
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Koalas
Kangaroos
Sugar gliders
Opossums
Monotreme Mammals
• Mammals with
reptilian-like features
including a cloaca.
• These mammals lay
reptile-like eggs.
• After the babies hatch,
the mothers nourish
their young with milk.
Monotreme Mammals
• Examples include:
– Duck-billed platypus
– Echidna