Arthropods Arthropoda - “ jointed legs. Largest animal phylum; includes insects, spiders shrimp, and centipedes. Jointed appendages include, legs, antennae, claws, & pinchers.
Body Cavity & digestive system; possess mouth & anus. Open circulatory system w/ a heart Nervous system is similar to annelids, but with larger brains Have compound eyes to detect color & motion Have featherlike gills, book gills or book lungs to respire
Skeletal Structure Have an external structure called an exoskeleton. Made up a protein & a carbohydrate called chitin. Sheds its exoskeleton as it grows in a process called molting. Is vulnerable to predators while new exoskeleton hardens
Class Insecta Three body regions: head, thorax, & abdomen. Head contains a pair of antennae, eyes, & a mouth. Insects are largest invertebrate class.
Thorax has 3 pair of jointed legs, & 1 or 2 pair of wings in most species. Abdomen is divided into 11 segments (No wings or legs attached to abdomen).
Only invertebrates capable of flight. - allows them to find food, home, and mates better and it allows them to escape predators.
Possess both simple & compound eyes (detect color and movement). Antennae are used for touch & smell. Open circulatory system carries food and waste. O 2 enters and CO 2 exits through spiracles (holes) on the abdomen and thorax.
Reproduction Reproduce sexually. Many undergo metamorphosis - series of changes controlled by hormones. Two types: Complete & Incomplete.
Complete Metamorphosis Most insects such as: butterflies, beetles, ants, bees, moths & flies develop through complete Metamorphosis. 4 stages: Egg, Larva, Pupa (resting), & Adult.
- Cephalothorax (fusion of head & thorax) & abdomen - 5 pairs of walking legs, 1st pair are claws. Abdomen Mandible Second antenna First antenna Cephalothorax Walking legs Cheliped Swimmerets Tail Carapace
Millipedes Round bodies with 2 pairs of legs per body segment. Possibly over 100 segments Feed on dead & decaying plant matter Roll up in a ball when disturbed. Some can expel cyanide gas or unpleasant chemicals as a defense mechanism.