Download KEY CONCEPT All vertebrates share common structures and

• PHYLUM CHORDATA
KEY CONCEPT
All vertebrates share common structures
and characteristics.
• Most chordates lose some or all of these
characteristics in adulthood.
Key concept all vertebrates are chordates not all
chordates are vertebrates
Sea squirts
Subphylum. Urochordata
Subphylum. Vertebrata
Subphylum. Cephalochordata
Phylum.Chordata
Chordata
Lancelet
Phylum Chordata contains all vertebrates
• Chordates share common features or structures at
some stage of development at some point in their life
cycle.
– Notochord
• Long, firm rod that extends along the back of the animal
becomes the vertebral column
– Hollow nerve cord
• Hollow tube that in chordates that becomes the brain and
spinal cord
hollow nerve cord
– pharyngeal slits
tail
notochord
• Gills in the throat region
– Postanal tail
pharyngeal slits
brain
Dorsal nerve cord
Postanal tail
Pharyngeal slits
•
•
•
•
•
•
•
Chordate Characteristics
Bilateral symmetry
Two pairs of appendages
Cephalization
Closed circulatory system
Coelom – body cavity that contains vital organs
Internal skeleton
deuterostomes
•An endoskeleton allows vertebrates to grow to large
sizes.
•internal
•made of bone or cartilage
• An endoskeleton can be
divided into two parts.
– Axial skeleton
– braincase (cranium)
– vertebrae
braincase
Pectoral
girdle
vertebrae
– Appendicular skeleton
Pelvic girdle
– Pectoral girdle
– Pelvic girdle
More complex for better motor control
Sensory detection of the animals
environment
(brain)
Skeleton becomes stronger to work
with bigger muscles
Allows more rapid movement
nervous
skeletal
Stronger heart to circulate
blood faster
circulation
Adaptations
respiration
Digest more food
Muscularized gut parastalsis
Digestive glands
Liver
Pancreas
digestive
Gill slit and muscular pharynx will
move more water over gills
More oxygen is extracted from
water
DON’T COPY Subphylum Urochordata
• Sea squirt
• Gill slits (pharyngeal
slits)
• Notochord
– Only in larva
• Adult has tunic
DON’T COPY Subphylum Cephalochordata
Lancelet
• Amphioxus
• Notochord length
of body
• Dorsal hollow
nerve cord
• Gill slits
• Segmented
muscles
Amphioxus
• There are seven classes of vertebrates.
1. Agnatha
2. Chondrichthyes
3. Osteichthyes
4. Amphibians
5. Reptilia
6. Aves
7. Mammalia
Kingdom Animalia Phyla Chordates 7 classes
characteristics
Separation
chacteristic
Skeleton
Circulation
heart
habitat
appendages
respiration
Agnatha
Chondrarithes
osticthesis
Amphibia
Reptilia
Aves
mammalia
Main Characteristic
Osteichthyes
Amphibia
Aves
Mammalia
mammals
bony fish
cartilaginous fish
Chondrichthyes
jawless
Agnatha
3. amphibia
Four limbs
5 aves
Feathers
2 JAWS
Jaws
6 mammals
Hair
1 Agnatha
Jaw is missing.
4 reptiles
scales
• There are 30,000 species of Fish – 20,000 are
Marine.
• The dominant aquatic vertebrates are the fish.
• 97% of fish are bony fishes.
• They belong to Phylum Chordata.
• Most fish use counter shading as a means of
camouflage.
Characteristics of All Fish
1. They are aquatic
2. They are cold blooded
3. They have a backbone
4. They have paired fins
5. They breath with gills
6. Lateral line system
7. Developed brain
Fish are vertebrates with gills and paired fins.
• Fish use specialized organs called gills to breathe
underwater.
– sheets of thick, frilly tissue filled with capillaries
– take in dissolved oxygen from water, release carbon
dioxide
– Have countercurrent flow
water
flow
• Fins are appendages that project from a
fish’s body.
– keep fish
stable
– redirect water
around fish as
it swims
– help fish
maneuver in
water
• All fish have a lateral line system.
– sensory system
– sensitive to small changes in water movement
lateral line
Parts of the fish brain
Olfactory lobe
cerebrum
Optic lobe
cerebellum
Medulla
body regions of a fish
thorax
tail
. head
Fins
Pelvic Fin
Class Agnatha
• Tunicates (worms) may be the closest relatives to
vertebrates.
• The first recognizable vertebrates were jawless fish.
• Two groups of jawless fish still exist today.
– lampreys
hagfish
Lampreys
• Characteristics
– Jawless
– http://dsc.discovery.com/videos/dirty-jobs-sealamprey-exterminator/
– Smooth skin
teeth
– Cylinder-like bodies
– Bones made of cartilage
– parasitic
mouth
•Mouth structures
•Sucker like mouth
•Rasping teeth
•Oral disk
Oral disk
Feeding
•Fasten to the side of a
fish
•Flip their body
•scrap a hole in the side
Reproduction
•Suck out the blood
&
tissues
reproduction
•
•
•
•
•
Freshwater lakes and streams
Lay eggs in hollows made in gravel
Eggs are fertilized externally
Worm like larvae hatch and burrow into the gravel
They remain there for 3 years
Hagfish
•
•
•
•
•
•
•
•
•
Bottom dwellers
Cold ocean waters
5 – 15 pairs of gills
Mucus-secreting glands all over their bodies
Sometimes called slime eels
Poorly developed eyesight
Slit-like toothed mouths
Scavengers
Hermaphrodites
– Produce sperm one year and eggs the next
– Internal fertilization
– Young hatch and look like the adult
Only two groups of jawed fish still exist.
• Cartilaginous
fish and bony
fish are still in
existence.
Jaws evolved from gill supports.
• Jaws developed from gill arches located around
the pharynx.
cranium
cranium
cranium
mouth
gill arches
mouth
mouth
• Jaws gave vertebrates a huge advantage as
predators.
Class Chondrichthyes
Cartilaginous fish have skeletons made of cartilage
Orders
– Holocephali include ratfish, a small group of
deep-sea fish.
– Elasmobranchs include sharks, rays, and
skates.
Rat fish
There are 300 species of cartilaginous fish
characteristics
• Jaws lined with rows of teeth that are constantly
replaced
• Skin is covered with small pointed teeth – placoid
scales
• 5 – 7 pairs of gills
• Two chambered heart
• Separate sexes
• Fertilization is internal
• Marine
• Carnivorous
• Detect prey with lateral lines system
Sharks
• Liver controls their buoyancy
• Dermal denticles - teeth like scales allow them to
taste with their skin
• Ampullae of Lorenzini in their jaws allow them to
sense electrical impulses
• They are all muscles and skin and can’t take much
abuse
Skates/Rays
• Have gills on their ventral side
• use spiracles to breath on top of their head
• primarily feed on mollusks, crustaceans, worms, and
occasionally smaller fishes. Some rays crush their prey
between their blunt teeth, sometimes referred to as
bony plates
• Often completely burying themselves in the sand or
soft sediment
• camouflaged by a grayish-brown, often mottled
coloration
Skates/Rays
• More than 200 species have been described, in 27
genera
• slow growth rates and, since they mature late, low
reproductive rates
• Among the best know rays are stingrays, which have
long, slim, whiplike tails armed with serrated,
venomous spines. A stingray lashes its tail only as a
defensive measure when it is caught, stepped on, or
otherwise disturbed.
Southern Stingray
Butterfly Ray
Gymnura micrura
Absence of
a Barb – sharp spines
Dasyatis americana
Absence of
a Barb
Absence of
a Barb – sharp spines
Clearnose Skate
Presence of
a Barb
Omit Great whites and the red triangle
1. Where is the greatest concentration of great
whites in the US
2. Why is it called the red triangle?
3. What are the main food sources of the
sharks?
4. Where is the red triangle?
5. How often do sharks need to feed?
6. Where do they patrol?
7. What has caused the greatest reduction in
their numbers?
8. What has been their saving grace?
Ray on the left
Skates on the right
• The major difference between rays and skates
is in their reproductive strategies. Rays are live
bearing (viviparous) while skates are egg laying
(oviparous), releasing their eggs in hard
rectangular cases sometimes called
"mermaid´s purses". Also, skates typically have
a prominent dorsal fin while the dorsal fin is
absent or greatly reduced in rays.
• Most rays are kite-shaped with whip-like tails
possessing one or two stinging spines while skates
have fleshier tails and lack spines. Rays protect
themselves with these stinging spines or barbs
while skates rely on thorny projections on their
backs and tails to for protection from predators.
• rays are generally much larger than skates.
External structures
female
Muscles tissue
male
liver
Internal structures
Gill slits
External Shark Anatomy Lab
1. Draw the lateral view of 1. Fins
the shark
• Anterior dorsal
2. Label the following
• Posterior dorsal
structures
• Caudal
• Lateral line
• Spiracle
• Eyes
• Gill slits
• rostum
• Pelvic
• pectorial
Ventral
1. Label the fins
2. Label the following
structures
• Clasper
• Cloacal opening
• Gill slits
• Nostrils
• Mouth
• ampullae of
Lorenzini
1. Chart all of the
view
structures and
functions
2. Chart the fins give the
name, number and
function
3. Sex your shark
4. What is the number
of teeth rows
5. What is the number
of gill slits
6. Describe the feel of
the shark
Internal examination of the shark
•
•
•
•
Draw and label each system
Chart each system
List all structures in bold print
Give their function