Arthropods

Chapter 28Biology

Auburn High Schoolp. 760 – 783

28.1: Characteristics of Arthropods

p. 761 – 766

General Characteristics

Phylum Arthropoda• Meaning – arthron = joint; pod = foot

• Jointed appendages, exoskeleton, varied life cycles, bilateral symmetry, coelomate invertebrate

• Grow by molting (the shedding of old exoskeleton)

Habitat• Land, water or air

Locomotion• Flying, crawling, or swimming

General Characteristics Reproduction

• Sexually• Internal in land species, external in aquatic species

• Some are hermaphrodites (barnacles)• Some are parthenogenesis (bees, wasp, & ants)

• form of asexual reproduction in which a new individual develops from an unfertilized egg

Significance• Pollinators (bees)• Scavengers (ants, beetles, etc.)• Parasites (mosquitoes) • Control insect population (spiders)

28.2: Diversity of Arthropods

p. 767 – 775

Class Arachnida

Include: spiders, scorpions, mites, and ticks

4 pairs of legs No antenna Body regions: chephlothorax and

abdomen

Class Crustaceans

Aquatic or damp terrestrial locations Exchange gases through feathery gills 2 pairs of antennae Have mandibles for crushing food Compound eye 5 pairs of walking legs 2 or 3 body sections

Class Crustaceans

Include: crabs, lobsters, shrimp, crawfish, barnacles, water fleas, pill bugs, and sow bugs

Class Chilopoda Class Diplopoda

Flatten bodies Carnivorous 15 – 181 body segments Include: centipedes

Cylindrical bodies Herbivores; Stink glands 100+ body segments 2 pair of legs per segment Include: millipedes

Class Merostomata (Horseshoe Crab)

Living fossils Semicircular exoskeleton Long pointed tail 4 pairs of walking legs 5 or 6 pairs of appendages that move

water over gills (swimmerets) Eat sea weed, worms, and mollusks

Class Insecta

3 body divisions (head, thorax & abdomen) 6 legs attached to thorax Most adults have 1 or 2 pairs of wings Exoskeleton (molt to grow) Undergo metamorphosis (egg – larvae – pupa

– adult or egg – nymph – adult) Habitat

• Found in most places

Metamorphosis of Insects

Characteristics of Insects

Feeding• All types

Locomotion• Crawling, flying, jumping or swimming

Reproduction• Eggs fertilized internally (sexually)

Significance• Damage crops, spread diseases, eat other insects,

pollinate

Characteristics of Insects

Include: dragonflies, fruit flies, butterflies, grasshoppers, ants, bees, wasps, katydids, preying mantis, roaches, beetles, bowel weevil, lice, and etc.

Pictures of Insects