1. Nonvertebrate Chordates, Fishes, and Amphibians
Ms. Moore
3-1-13

2. What is a Chordate? Phylum: Chordata
A chordate is an animals that has, for at least some stage of life, a dorsal, hollow nerve cord; a notochord; pharyngeal pouches; and a tail that extends beyond the anus.
Hollow nerve cord: nerves branch off and connect to organs
Notochord: long supporting rod that runs through the body just below the nerve cord
Pharyngeal pouches: paired structures in the throat region; can develop slits  gills in some chordates
Tail: can contain bone and muscle; can be used for motility

3. Characteristics of Chordata

4. Most Chordates are Vertebrates
Figure 30-2
96% of all chordates are placed in the subphylum: Vertebrata  vertebrates
Vertebrae: backbone replaces the notochord in most developing vertebrates; encloses and protects the spinal cord
Part of endoskeleton
Grows as the animal grows
Made up of living and non living cells

5. Nonvertebrate Chordates
2 groups of Chordata do not have a backbone
Soft bodied marine animals
550 mya = ancestors!
Tunicates
Subphylum: Urochordata
Filter feeders
Open Circulatory
Lancelets
Subphylum: Cephalochordata
Small fishlike creatures
Live on sandy ocean body
Closed Circulatory
Diffusion through skin

6. Mini Lab Draw a picture depicting a typical: Label all parts
Tunicate (p 769)
Lancelet (p 770)
Label all parts

7. What is a Fish?
Fishes are aquatic vertebrates, most fishes have paired fins, scales, and gills.
Fins = movement
Scales = protection
Gills = exchanging gases

8. Evolution of Fishes
The evolution of jaws and paired fins were important developments during the rise of fishes.
First Fishes: 510 mya
Jawless with armored plates
The Age of Fishes: mya
Ancestors of hagfishes and lampreys
Arrival of Jaws and Paired Fins
Filter feeders  herbivores and carnivores
Fins attached by cartilage  movement
Cartilage: strong tissue that supports the body; softer and more flexible than bone
Modern Fishes
Ancestors of sharks and rays: cartilage
Bony fishes: bone

10. Form and Function in Fishes
Feeding
Herbivores, carnivores, parasites, filter feeders, and detrius feeders
Mouth  Esophagus  Stomach  other organs  Intestines  Anus

11. Respiration Circulation
Gills: located on either side of the pharynx; made up of feathery filaments
Lungs: specialized organs to help in shallow waters
Circulation
Closed circulatory system: single loop
Heart  gills  body  heart
Atrium: large muscular chamber located in the heart
Ventricle: thick-walled, muscular chamber; pumping portion of the heart

12. Response
Fishes have well-developed nervous systems organized around a brain
Cerebrum: voluntary activities; senses
Cerebellum: coordination
Medulla oblongata: fx of organs
Lateral line system: sense vibration/movement
Movement
S-shaped movement—muscles in the back
Fins increase surface area = faster
Swim bladder: gas filled organ that adjusts buoyancy

13. Reproduction Eggs can be fertilized externally or internally
Oviparous: eggs hatch outside the mother’s body; salmon
Ovoviviparous: eggs stay in the mother’s body after internal fertilization; guppy
Viviparous: embryos stay in the mother’s body after internal fertilization; some sharks

14. Groups of Fishes Jawless Fishes Sharks and Relatives Bony Fish
Class: Agnatha
No true teeth or jaws
Skeletons made of fibers and cartilage (keep notochords)
Include:
lampreys—filter feeders as larvae/parasites as adults
Hagfishes—detrius feeders; slime; 6 hearts; open; knots!
Sharks and Relatives
Class: Chondrichthyes (a.k.a. cartilage)
Include: sharks, rays, skates, and others
Bony Fish
Class: Osteichthyes
Skeleton made of bone
Almost all include ray-finned fishes

15. Ecology of Fishes Aquatic Life Movement/Migration
Freshwater = low salt concentration
Ocean = high salt concentration
Movement/Migration
Anadromous fishes: ocean dwellers migrate to freshwater to breed
Lampreys
Salmon
Catadromous fishes: freshwater fishes migrate to ocean to breed
European eels

16. Mini Lab Draw the diagram of the fish, label all parts (p774)
Draw the diagram of a fish brain, label all parts (p777)
Fill out long study guide Agnatha  Osteichthyes
Complete handout

17. What is an Amphibian?
An amphibian is a vertebrate that, with some exceptions, lives in water as a larva and on land as an adult, breathes with lungs as an adult, has moist skin that contains mucous glands, and lacks scales and claws.
Evoultion of Amphibians:
Bones became stronger = movement on land
Lungs = breath air
Sternum = protection of organs

18. Form and Function in Amphibians
Feeding
Tadpoles: filter feeders or herbivores (algae) with long intestines
Adult: meat-eating with shorter intestines
Sticky tongues to catch prey
Mouth  esophagus  stomach  intestine  liver/pancreas/gallbladder  colon  cloaca (digestive wastes, urine, eggs/sperm leave body)
Respiration
Larval: gas exchange through skin/gills
Adult: lungs some skin/mouth cavity (always exceptions—lung less salamanders)

19. Circulation Excretion Reproduction
Double loop system: first carries O2 rich blood from heart to lungs and skin and back; second carries O2 rich blood from heart to rest of body and back
3 chambers: left atrium, right atrium, and ventricle
Excretion
Kidneys  ureters  bladder/cloaca
Reproduction
Frog eggs laid in water to undergo external fertilization
Eggs hatch into tadpoles
Tadpoles gradually grow limbs, lose tails/gills, and become carnivorous
Young adults move onto land

20. Movement Response Larva: move like fishes
Adult: use front and back legs to move in a variety of ways
Response
Brain much like a fish
Well developed nervous and sensory systems
Nictitating membrane: protects eye from underwater damage/keeps moist
Tympanic membrane: eardrums on each side of the head

21. Groups of Amphibians Salamanders (and Newts) Frogs and Toads
Order: Urodela
Long bodies and tails; most have 4 legs
Larva and adults are carnivorous
Moist environment or underwater
Frogs and Toads
Order: Anura
Jump! Frogs = long legs, near water; Toads = shorter legs; moist woods, even deserts
Caecillians
Order: Apoda
Legless, carnivorous, live in water or burrow in moist soil, many have fishlike scales in skin

22. Ecology of Amphibians Must live near water Protection from predators
Some exceptions: desert amphibians have special adaptations
Protection from predators
Skin colorings/markings
Poison glands in skin
Global decline
Amphibians are very susceptible to the environment

23. Mini Lab Draw the following in your lab manual: Figure 30-23 (p784)
Notice the location of the organs
Figure (p785)
Use different colors to demonstrate the direction of blood throughout the amphibian
Create a life cycle for an amphibian
Can use figure on p786