1. Invertebrates
Chapter 33

2. Most animals - invertebrates - do not have backbone.

4. 1Phylum Porifera
Sponges - lack nerves and muscles; sessile (non-motile).
Most marine, live in water.
Most hermaphrodites - each individual produces sperm and eggs.
Can regenerate lost parts.

6. Sponges perforated with holes so water can flow through them (suspension-feeding)
Water drawn through pores into central cavity (spongocoel) and flows out through larger opening (osculum)

8. 2Phylum Cnidaria 1st organisms to have true tissues.
Basic body plan - sac with central digestive compartment (gastrovascular cavity)
Jellyfish, corals, sea anemones, and hydras.
Have nerve nets - very primitive nervous systems that move towards stimuli.

10. 2 body plans in cnidarians.
1Polyp stage - sessile; some live whole life this way.
2Medusa stage - cnidarian can swim freely.
Can move through both stages during lifetime.

12. Cnidarians have nematocysts - stinging cells.
Phylum Cnidaria divided into 3 major classes: Hydrozoa (hydra), Scyphozoa (true jellyfish), and Anthozoa (sea anemones).
Cnidarians - carnivores - use tentacles to push food into gastrovascular cavity.

15. 3Phylum Ctenophora Comb jellies named for fused cilia.
Resemble medusa stage of cnidarians.
No stinging cells present.

17. 4Phylum Platyhelminthes
Flatworms, both parasitic and non-parasitic.
Flatworms have mesoderm - middle layer of tissues - makes them bilateral.

18. http://www. waterworxbali

19. Gastrovascular cavity with only 1 opening; absorb materials across tissue.
Flatworms are divided into four classes: Turbellaria, Monogenia,Trematoda (flukes), and Cestoidea (tapeworms).

20. Turbellaria

21. Trematoda

22. Cestoidea

23. Planaria - scavengers found in ponds.
No organs specialized for circulation or respiration; exchange gases across membranes.
Have eyespots for detecting light and lateral flaps for smell.
Nervous systems more advanced than cnidarians; reproduce asexually through regeneration (can sexually reproduce).

24. Planaria

25. Trematodes parasites with suckers to attach to victims.
Blood fluke - parasite of humans.
Tapeworms have suckers and hooks on head; anchor worm in digestive tract of host.

26. Blood fluke

27. 5Phylum Rotifera
Rotifers - complete digestive tract with separate mouth and anus.
Internal organs in pseudocoelom - body cavity not completely lined with mesoderm.
Functions as circulatory system -nutrients dissolved in cavity.
Have hydrostatic skeleton - movement.

29. Some rotifers exist only as females that produce more females from unfertilized eggs - parthenogenesis.

31. 6Phylum Mollusca Snails, slugs, clams, squid, and octopus.
Mollusks soft-bodied animals - most protected by hard shell of calcium carbonate.
All have similar body plan with muscular foot (locomotion), visceral mass with most of internal organs, and mantle.

33. Use radula to feed - allows them to scrape up food.
Most mollusks have separate sexes.
4 common classes - Polyplacophora (chitons), Gastropoda (snails and slugs), Bivalvia (clams, oysters, and other bivalves), Cephalopoda (squids, octopuses, and nautiluses).

35. Chiton

36.
Gastropod

37.
Bivalves

38. Cephalopod

39. Gastropods have shells that they can retreat into (means stomach-foot)
Lining of mantle acts like lungs - allows them to live on land (garden snails and slugs).

42. Bivalves - 2-shelled - clams, oysters, mussels, and scallops.
Most bivalves - suspension feeders, trapping fine particles in mucus that coats gills.
Usually sessile - cannot move during lifetime.

45. Cephalopods have reduced shell and include nautilus, squid, and octopus.
Nautilus - external shell.
Have well-developed nervous system with complex brain and well-developed sense organs.
Cephalopods have closed circulatory system.

46. Nautilus

47. 6Phylum Annelida Annelids - segmented worms.
Digestive system - pharynx, esophagus, crop, gizzard, and intestine.
Closed circulatory system with 5 chambers act as heart to pump blood.

49. Each segment - pair of excretory tubes, (metanephridia) - remove wastes from blood and coelomic fluid exits through pores.
Brainlike pair of cerebral ganglia lie above and in front of pharynx.
Some earthworms reproduce asexually (regeneration), also reproduce sexually.

51. Hermaphrodites - exchange sperm which are stored, then later fertilize egg.
Phylum Annelida divided into 3 classes: Oligochaeta (earthworms), Polychaeta (bristle worms), and Hirudinea (leeches).

52.
Polychaeta

54. http://kentsimmons. uwinnipeg

55. Segmentation of worms allow for specialization.
Hirudinea - leeches – parasitic, suck blood off hosts.
Used in medicine because they promote circulation in areas of body.

56. Hirudinea

57. 7Phylum Nematoda Roundworms - found in wet environments.
Complete digestive tract - use fluid in pseudocoelom to transport nutrients (lack circulatory system)
Reproduce sexually, can be parasitic (trichinosis)

59. 8Phylum Arthropoda
Characterized by body segmentation, a hard exoskeleton, jointed appendages.
Body of arthropod completely covered by cuticle - exoskeleton constructed from layers of protein and chitin.
Have to molt in order to grow.

61. Arthropods have well-developed sense organs, including eyes for vision, olfactory receptors for smell, antennae for touch and smell.
Arthropods - open circulatory system - fluid pumped by heart through short arteries into sinuses surrounding tissues and organs.

63. Aquatic arthropods - gills for breathing; terrestrial arthropods - internal structures for breathing.
Insects - tracheal tubes to breathe.

65. Trilobites - extinct arthropods - no specialization.
Chelicerates mostly extinct; 4 species, (i.e. horseshoe crab) still alive.
Modern chelicerates members of class Arachnida (scorpions, spiders, ticks, and mites).

66. Trilobite

67. Horseshoe crab

70. Most spiders - book lungs allow them to breathe.
Some can inject poison to kill prey.

72. Millipedes - worm-like with 2 pairs of walking legs on each segment.
Centipedes - terrestrial carnivores.
Insects (class Insecta) outnumber all other forms of life combined - 26 orders.

73. Millipede

74. Insects - ability to fly.
Metabolic wastes removed from fluid by Malpighian tubules, pockets of digestive tract.
Respiration done by branched, chitin-lined tracheal system - carries O2 from spiracles directly to cells.
Nervous system - pair of ventral nerve cords with several segmental ganglia.

77. Metamorphosis occurs in insects; can be either incomplete (grasshoppers) or complete (butterflies).
Reproduction in insects usually sexual, with separate male and females.

79. Many arthropods live in water.
Crustaceans include lobsters, crabs, crayfish, shrimp, and barnacles.

81. Small crustaceans exchange gases across thin areas of cuticle; larger species have gills.
Circulatory system open - heart pumps fluid into short arteries then into sinuses that bathe organs.
Nitrogenous wastes excreted by diffusion through thin areas of cuticle, glands regulate salt balance of fluid (hemolymph).

82. http://limnology. wisc

83. Crustaceans - different sexes.
3 groups of crustaceans: isopods (pill bugs, or wood lice), copepods (small crustaceans) and decapods (lobsters, crayfish, crabs, and shrimp).
Barnacles also crustaceans.

85. Phylum Echinodermata Most echinoderms sessile, or slow-moving.
Most - prickly skin.
Water vascular system - network of hydraulic canals branching into extensions (tube feet) used for movement, feeding, gas exchange.

87. Sexual reproduction in echinoderms - release of gametes by separate males and females into seawater.
6 classes: Asteroidea (sea stars), Ophiuroidea (brittle stars), Echinoidea (sea urchins, sand dollars), Crinoidea (sea lilies, feather stars), Holothuroidea (sea cucumbers), Concentricycloidea (sea daisies)

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89. Sea stars can attach to objects with tube feet.
Can regenerate lost parts.
Brittle stars do not have suckers on tube feet - have long and flexible arms.

91. Sea star

92. Brittle star

93. Sea urchins and sand dollars - no arms, have 5 rows of tube feet used for locomotion.
Sea lilies attached to objects by stalks, feather stars crawl using their long, flexible arms.
Sea cucumbers lack spines - have tube feet.

94. Sea urchin

95. Sea lily

96. Sea cucumber