1. Animalia Notes Continued…
Part 2
*See class website for online virtual dissections!

2. Segmented Worms
Earthworms, leeches, and other segmented worms live in water or damp soil
Leeches were once used to suck out people’s “excess” blood and reduce harmful high blood pressure.
Leeches are uses today to produce anti-blood-clotting medicines, to suck blood from bruises, and to stimulate blood circulation in severed limbs that have been surgically reattached.

3. Segmented Worms (cont.)
Each segment is separated from its neighbors by a membrane and has its own excretory system and branches of the main nerves and blood vessels that run the length of the animal.
Both segmented and unsegmented worms have definite anterior and posterior ends.
Food travels through the digestive system in one direction; from anterior to posterior.
A cluster of nerve cells at the anterior end serves as a simple brain.
Reproduction occurs by splitting or by mutual fertilization.

4. Phylum Annelida Earthworms, leeches- segmented worms
Each segment is separated from the next by a membrane
Closed circulatory system with blood vessels that run the length of the animal.
Has a complete excretory and digestive system
Branches of the main nerves and clusters of nerve cells at the anterior end serves as a simple brain.
Live in water or damp soil; Bilateral symmetry
Reproduction occurs by splitting or by mutual fertilization (hermaphrodites)

5. Ear thworms and Their Relatives
Eat their way through soil
Have a closed circulatory system
Giant
Australian
earthworm
Mouth
Brain
Dorsal
vessel
Coelom
Digestive
tract
Mucus-secreting
organ
Segment
wall
Anus
Bristles
Blood vessels
Nerve cord
Pumping segmental vessels
Ventral vessel
Excretory
Segment wall
(partition
between
segments)
Epidermis
Circular
muscle
Longitudinal
Intestine
Figure 18.10A

8. Phylum Annelida (cont.)
Leeches

9. Phylum Mollusca
Includes snails, clams, slugs, squid, and their relatives.
Bilateral sym.; coelomates
Radula- scrapes up food; complete digestive tract
Separate sexes; sexual reproduction
Mollusks have soft bodies with 3 parts:
A visceral mass that contains most of the organs
2) A muscular “foot” that is used in movement
3) A thick flap called a mantle, which covers the body and in most species produces a heavy shell of calcium compounds.

10. Phylum Mollusca (cont.)
Mollusks pump water through gills- both for oxygen and food for clams and oysters.
Squid and octopi use the pump for jet propulsion through the water in search of prey.

11. Phylum Mollusca

12. Diverse mollusks are variations on a common body plan
All mollusks have a muscular foot and a mantle, which may secrete a shell that encloses the visceral mass
Many mollusks feed with a rasping radula
Visceral mass
Mantle
Radula
Mouth
Nerve
cords
Foot
Digestive tract
Shell
Digestive
tract
Reproductive
organs
Heart
Coelom
Kidney
cavity
Anus
Gill
Figure 18.9A

13. Gastropods
The largest group of mollusks and include the snails and slugs
Figure 18.9B, C

14. Bivalves
Have shells divided into 2 halves and include clams, oysters, mussels, and scallops
Figure 18.9D

15. Cephalopods Adapted to be agile predators and
include squids and octopi
Figure 18.9E, F

16. Phylum Arthropoda
The largest animal phylum- 1 million species of crabs, shrimp, spiders, scorpions and insects make up this phylum
Have jointed appendages; segmented bodies
Exoskeletons made of chitin
Molt; have heads with many sensory organs.
Bilateral
Simple and complex eyes that detect only light intensity and form images
Antennae that smell chemical substances in the environment

17. Phylum Arthropods (cont.)
Sexual Reproduction- where sperm is released inside the female’s body, not in water.
Larvae of many species develop into very different adults, a process called metamorphosis.
Can develop resistance to insecticides- demonstrates how quickly they adapt to a changing environment.
Short generations and many offspring increase the chance that random mutations will produce a few resistant individuals

18. Ar thropods are segmented animals with jointed appendages and an exoskeleton
Antennae
(sensory
reception)
Head
Thorax
Cephalothorax
Abdomen
Swimming
appendages
Walking legs
Mouthparts (feeding)
Pincer (defense)
Figure 18.11A

19. Chelicerates
Include horseshoe crabs and arachnids, such as spiders, scorpions, mites, and ticks
A scorpion (about 8 cm long)
A black widow spider (about
1 cm wide)
A dust mite (about 420
µm long)
Colorized SEM 900
Figure 18.11B, C

20. Millipedes and Centipedes
Are identified by the number of jointed legs per body segment
Figure 18.11D

21. - Are nearly all aquatic - Include crabs, shrimps, and barnacles
Crustaceans
- Are nearly all aquatic
- Include crabs, shrimps, and barnacles
Figure 18.11E

22. Insects are the most diverse group of arthropods
Insects have a 3 -par t body consisting of
Head, thorax, and abdomen
Three sets of legs
Wings (most, but not all insects)
Many insects undergo incomplete or complete metamorphosis

23. A. Order Orthoptera B. Order Odonata
Grasshoppers, crickets, katydids, and locusts
B. Order Odonata
Dragonflies and damselflies
Head
Thorax
Abdomen
Antenna
Forewing
Eye
Mouthparts
Hindwing
Figure 18.12B
Figure 18.12A

24. C. Order Hemiptera D. Order Coleoptera
Bedbugs, plant bugs, stinkbugs, and water striders
D. Order Coleoptera
Beetles
Figure 18.12C
Figure 18.12D

25. E. Order Lepidoptera F. Order Diptera Moths and butter flies
Flies, fruit flies, houseflies, gnats, mosquitoes
Figure 18.12E
Haltere
Figure 18.12F

26. G. Order Hymenoptera
Ants, bees, and wasps
Figure 18.12G

27. Phylum Echinodermata Sea stars and sea urchins. Reproduce sexually.
Sperm and eggs are released in water, where they join and fertilize
Movement by seawater into and out of a system of internal tubes.

28. The water vascular system - has suction cup–like tube feet used for respiration and locomotion
Anus
Spines
Tube feet
Canals
Stomach
Figure 18.13A

29. Phylum Echinodermata

30. Phylum Chordata
Vertebrates-fish, amphibians, reptiles, birds, and mammals.
Full development of organ systems
Mostly sexual reproduction
4 defining characteristics:
Stiff dorsal rod helps to organize the embryo's development.
The central nervous system (brain and spinal cord) is tubular
Their sides have slits just behind the head. These pharyngeal slits (pharynx means “throat”) becomes gill slits of adult fish. In air-breathing chordates, they develop into various organs such as internal parts of the ears
They have a tail; in humans it’s the tailbone, or coccyx, which curls internally.

31. Phylum Chordata

32. Lampreys are ver tebrates that lack hinged jaws and paired fins
Figure 18.16A
Most vertebrates have hinged jaws which may have evolved from skeletal supports of the gill slits
Gill
slits
Skeletal
rods
Skull
Mouth
Figure 18.16B

33. CLASS: Fish
Jawed ver tebrates with gills and paired fins include sharks, ray-finned fishes, and lobe-fins

34. Have a flexible skeleton made of car tilage Include sharks and rays
Chondrichthyans
Have a flexible skeleton made of car tilage
Include sharks and rays
Figure 18.17A

35. Ray-finned Fishes
A skeleton reinforced with a hard matrix of calcium phosphate
Operculi that move water over the gills
A buoyant swim bladder
Gills
Bony skeleton
Dorsal fin
Anal fin
Swim bladder
Heart
Pectoral fin
Operculum
Pelvic fin
Rainbow trout,
a ray-fin
Figure 18.17B

36. Have muscular fins suppor ted by bones
Lobe-fins
Have muscular fins suppor ted by bones
Figure 18.17C

37. CLASS: Amphibians
The first tetrapods—ver tebrates with 2 pairs of limbs allowing movement on land
Bones
supporting
gills
Tetrapod
limb
skeleton
Figure 18.18A

38. Include frogs, toads, and salamanders
Most amphibian embryos and larvae must develop in water
Figure 18.18B–D

39. Terrestrial adaptations include
CLASS: Reptiles
Amniotes — tetrapods with a terrestrially adapted egg
Terrestrial adaptations include
Waterproof scales
A shelled, amniotic egg
Ectothermic
Figure 18.19A, B

40. Dinosaurs were the most diverse reptiles to inhabit land
Largest animals ever to inhabit land
May have been endothermic, producing their own body heat
Figure 18.19C

41. Considered feathered reptiles with adaptations for flight
CLASS: Birds
Considered feathered reptiles with adaptations for flight
Birds thought to have evolved from small, two-legged dinosaurs called theropods
Wing claw
(like dinosaur)
Teeth
Feathers
Long tail with
many vertebrae
(like dinosaur)
Figure 18.20A

42. Birds are reptiles that have
Wings, feathers, endothermic metabolism, and many other adaptations related to flight such as light bones
Flight ability is typical of birds but there are a few flightless species
Figure 18.20B
Figure 18.20C

43. CLASS: Mammals
Amniotes that have hair, produce milk, and are endothermic
Hair, which insulates their bodies
Mammary glands, which produce milk
Monotremes lay eggs
Figure 18.21A

44. The embryos of marsupials and eutherians are nur tured by the placenta within the uterus
Marsupial offspring complete development attached to the mother, usually inside a pouch
Figure 18.21B

45. Eutherians- placental mammal complete development before bir th
Figure 18.21C

46. The End of Animalia Notes!