1. Nonvertebrate Chordates, Fishes & Amphibians
Chapter 30-32
Nonvertebrate Chordates, Fishes & Amphibians
Reptiles & Birds
Mammals
Unit 9--Vertebrates

2. Phylum Chordata Characteristics:
At some time in their life, all chordates have:
A dorsal nerve cord = gives rise to spinal cord
A notochord = flexible supporting rod that gives rise to vertebrae
Postanal Tail that extends beyond the anus
Pharyngeal slits = gives rise to gills
Most in subphylum Vertebrata

3. Dorsal, hollow nerve cord
Located on the back (dorsal) part of the body
Nerves branch from this to all parts of the animal’s body

4. Notochord Located beneath the nerve cord Long supporting rod
Embryonic Ciona with visible notochord
Doe Joint Genome Institute
Located beneath the nerve cord
Long supporting rod
For most vertebrates, the notochord is present only in the embryo stage.
In some, vertebrae (backbone) replaces the notochord.

5. Notochord formation

6. Pharyngeal pouches Paired structures in the throat (pharynx) region
For fishes, slits develop that connect the pouches to the outside of the body, becoming gills.

7. human embryo with tailbud
Postanal tail
Extends beyond the anus
Bone and muscle within
Facilitates in swimming
human embryo with tailbud

8. Chordate Cladogram Section 30-1 Mammals Birds Reptiles Amphibians
Fishes
Nonvertebrate chordates
Invertebrate ancestor

9. Subphylum:
Urochordata = Tunicate (sea squirt) only larva has all characteristics

10. Subphylum: Cephalochordata = Lancelets
the only adult to retain all characteristics

11. Lancelet characteristics
Small, fishlike animals
Live on ocean floor
An adult lancelet has a mouth that connects to the pharynx, which secretes a sticky mucus to trap
food.
Closed circulatory system but no true heart

12. Subphylum Vertebrata:
Class Agnatha = the jawless fishes
Ex: sea lampreys & hagfish

14. Lamprey are external parasites, 1 while hagfish are “bottom feeders.”

15. Class Chondrichthyes
Cartilaginous fishes
Ex: Sharks, rays & skates

16. Sharks have several 6-10 rows of replaceable
teeth and toothlike placoid scales

17. Shark bite
Note the size of the shark tooth as compared the size of an average adult hand.

18. Class Osteichthyes Bony fish (with jaws & paired fins)
Ex: sea horse, lion fish, perch, trout, etc

19. Fish anatomy: Overlapping scales for protection
Gills with countercurrent exchange
Operculum = gill cover
Flattened bodies to increase speed

20. Respiration Most fishes use gills.
Gills are made up of feathery, threadlike structures called filaments.
The operculum, a bony covering, protects the gill slit(s).

21. Feeding Types of feeders
Herbivores: vegetative matter only
Carnivores: meat only
Parasites: feeds on other animals
Filter feeders: sifts matter out of water
Detritus feeders: feeds on dead or decaying matter
Food enters the mouth, stomach, pyloric ceca (digestive enzymes), intestines, and out the anus.

22. Movement
Alternating muscles on either side of the spine allows for S-shaped curve that pushes water
Fins for directional movement
Swim bladder: helps to adjust for buoyancy
swim bladder

23. Response
Well-developed brain and chemoreceptors to detect taste and smells
Lateral line system that detect vibration and current changes

25. Class Amphibia
“double life”
Ex: frogs toads, salamanders, newts

26. Amphibian characteristics
Vertebrate
Lives in water as a larva but on land as an adult
May returns to water to reproduce
Uses gills as larva but lungs as an adult
Moist skin with mucus glands
No scales or claws

27. Amphibian Anatomy Inefficient 3 chambered heart
“Skin breathing” to help inefficient lungs
Moist skin
Webbed feet, no claws
Metamorphosis

28. Reptilian characteristics
Dry, scaly skin
Lungs
Internal fertilization
Terrestrial eggs with several membranes
Double-loop circulatory system
Strong limbs
Ectothermic
Vertebrate
Diverse habitats

29. Reptile anatomy
Ectothermic (cold-blooded) = body temp changes with environment
Dry, waterproof skin with claws
Partially divided 3 chambered heart

30. Class Reptilia Ex: snakes, lizards, turtles, alligators
Tuatara = only member is its order

31. Amniote Egg allows reptiles to lay eggs on land
CHORION

33. Rattlesnakes are “Pit vipers” with a heat sensitive
organ that detects warm-blooded prey

35. Class Aves (the birds) Endothermic (warm-blooded) body temp constant
4 chambered heart
Well-developed lungs

36. “Volta” the bald eagle – Alaskan Bird Rehabilitation Center
Bird characteristics
Reptile-like
Aerodynamic feathers
Two legs covered with scales
Front limbs modified into wings
Highly efficient metabolism
Strong, lightweight bones
Levy
“Volta” the bald eagle – Alaskan Bird Rehabilitation Center

37. Information from UC Berkeley, Museum of Paleontology
Reptiles vs. Birds
Feathers are produced by tissues similar to those that produce reptile scales.
Birds have scales on their feet.
Birds lay eggs like reptiles.
The soft anatomy (musculature, brain, heart, and other organs) all are fairly similar.
Information from UC Berkeley, Museum of Paleontology

38. Bird Anatomy
Feathers for insulation, protection & coloration, assist in flight
Hollow bones for lightweight

39. Birds reduce weight for flight whenever possible,
i.e. air sacs attached to lungs & one ovary in females.

41. Compare:
Heart chambers
Skin coverings
Respiration types
Cold vs Warm-blooded
Reproduction types

42. Mammal characteristics
Hair
Mammary glands
Require oxygen
Four chambered hearts
Endothermic
Sea World, whale calf nursing

43. Class Mammalia Hair (to insulate, camouflage, etc)
Mammary glands (to nurse young)
Viviparous (bear live young)
Specialized teeth (determines lifestyle)
Nails, claws or hooves

44. Regulating Body Temperature
Endotherm: animal that can generate body heat internally through metabolic processes
Body hair: insulates
Subcutaneous fat: layer beneath the skin to help conserve heat
Sweat glands: evaporative cooling
Regulating body temperature = homeostasis

45. Hair
Only mammals have hair. Whales and dolphins (marine mammals) have sensitive bristles on their snouts.
Functions: insulation, camouflage, sensory input (environmental awareness)

46. Feeding
Because of metabolic rate, mammals must eat 10x the amount of food as reptiles.
Herbivores: consume only vegetative matter
Carnivores: consume only meat
Omnivores: consume meat and vegetables
Filter feeders: sift out plankton and small fish from water
Name an example of each type of animal feeder.

47. Specialized teeth
Section 32-1
CARNIVORE
HERBIVORE
Molars crush and grind food. The ridged shape of the wolf’s molars and premolars
allows them to interlock during chewing, like the blades of scissors. The broad,
flattened molars and premolars of horses are adapted for grinding tough plants.
Chisel-like incisors are used for
cutting, gnawing, and grooming.
Canines are pointed teeth. Carnivores
use them for piercing, gripping, and tearing.
In herbivores, they are reduced or absent.
Jaw joint
Jaw joint
Horse
Wolf
Figure 32–4 The Jaws and Teeth of Mammals (p. 823)

48. Respiration
All mammals, even marine, have lungs to breathe in oxygen and exhale carbon dioxide.
The diaphragm muscle lowers to help expand the chest cavity for greater volume.

49. Excretion
Kidneys help mammals maintain homeostasis (water and salt balance).

50. Response Mammals have the most highly developed brains.
Diurnal animals have the best developed color vision since these animals are awake during daylight.
Mammals also have highly developed sense of smell and hearing.

51. Chemical Controls
Endocrine glands: produce and secrete hormones that affect other organs and tissues
Hormones can regulate mammal behavior and vital functions such as maintaining blood sugar or calcium levels.

52. Fighting Disease
Immune systems help mammals ward off pathogens, disease-causing microorganisms, that may invade the body.

53. Reproduction All mammals…
Internal fertilization: male deposits sperm inside the female reproductive tract
requires mother’s milk for nourishment when young
display maternal care

54. Classification by reproduction:
Monotremes (egg-laying)
Ex: platypus& echidna
Marsupials (pouched)
Ex: koala, kangaroo & opossum

55. Reproduction Different ways that fetal mammals develop
Monotremes: lay eggs
Platypus, spiny anteaters (echidnas)
Marsupials: live birth of young that then finish development in an external pouch
Kangaroo, koala, wombat
Placental: nutrients, oxygen, carbon dioxide, and wastes are exchanged between embryo and mother through the placenta structure
Primates, dogs, cats, pigs, horses, etc.

56. Placental Mammals
Include 95% of
all Mammals
Includes 15+ orders

57. Rodentia (gnawing)
largest, most successful order

58. Insectivores = moles…
include smallest mammal, the shrew

59. Edentates (toothless)
most primitive

60. Chiroptera = bats
Bats are only mammals capable of “true” flight

61. Carnivora
special traits for hunting

62. Cetaceans = whales, dolphins
Aquatic mammals are capable of
holding their breath for several hours

63. ___dactyla Hoofed mammals Are grouped by Number of toes (even or odd)
They tend to be
Large grazers

64. Probosiceans = elephants
Trunk-nosed mammals have
only 2 species, African and Indian

65. Primates have opposable thumbs & superior intelligence They are the
only mammal
to make use
of tools