Invertebrate Zoology 8 Major Phyla

Phylum Arthropoda Means “jointed foot” - all appendages have hinges Most numerous of all animals 5 major Classes grouped by pairs of legs (1,2,3,4,5)

Phylum Arthropoda: Class Chilopoda: Centipedes 1 pair of legs per segment Fast, carnivores Many poisonous (remember “Purple Death”?)

Phylum Arthropoda: Class Diplopoda: Millipedes 2 pairs of legs per segment Slow, herbivore/scavenger of dead plants Roll into ball for defense

Phylum Arthropoda: Class Insecta 3 Pairs of Legs TOTAL Most numerous and successful of all animals 10 million+??? (75% of all known animals are insects) Great adaptations

Even More Insects

Insect Mimic The Viceroy Butterfly (left) evolved to look like the Monarch Butterfly (right). BOTH species taste bad to birds (the Monarch is poisonous)

Insect Mimics

Phylum Arthropoda: Class Arachnida: Spiders 4 Pairs of Legs TOTAL 2 Body Segments (head and chest fused) No antenna All Make Silk but not all spin webs Incredible insectivores Only 2 deadly enough to kill humans in the U.S. California Trapdoor Spider

Phylum Arthropoda: Class Arachnida: Spiders Black Widow Brown Recluse

Other Arachnids Deer Tick Dust Mite Scorpions

Phylum Arthropoda: Subphylum Chelicerata: Class Meristomata: Horseshoe Crabs Their ancestors date back over 400 million years. They survived mass extinctions – more related to spiders.

Phylum Arthropoda: Subphylum Crustacea 5 Pairs of Legs (or more) Almost all aquatic Oldest Arthropod group Great body segmentation (shows relationship to what group?) Lobsters, crabs, shrimp Dog Lobster

Other Crustaceans Crayfish Isopod: known as Pill bug or Sow bug. Isopod: Woodlouse Copepod

Other Crustaceans King Crab Barnacles