ARTHROPODA

Subphyla

• Crustaceans- Class Malacostraca -shrimp, lobster, crab

• Chelicerates- Class Arachnida -spiders, mites, scorpions

• Myriapeds- centipedes, millipedes

• Hexapods- Class Insecta

• This phylum is the largest with over 1,000,000 species

Characteristics

• Exoskeleton, segmented body, jointed appendages

• “arthros” means joint, “podos” means foot or leg

• Bilateral symmetry• Metamorphosis-

larva, pupa, adult• Molting

Anatomy

• Appendages can be wings, antennae, legs, mouthparts

• Exoskeleton – protects and helps prevent evaporation of water

• Open circulatory system

• Coelomates• Ganglia – mass of

nerves serves as brain

Anatomy

• Respiration occurs through lungs or exoskeleton if land organism. If lives in water, gills.

• Arthropods have full muscular and excretory systems.

• Body covering is exoskeleton

Feeding

• Every feeding type is represented in phylum arthropoda

• Scavengers, predators, herbivores, parasites, carnivores, omnivores,

Reproduction

• Almost all reproduce sexually

• Asexual- A few reproduce by parthenogenesis where an egg can develop into an adult with no sperm (ants, bees, wasps, and aphids)

Habitat

• Arthropods can be found in almost every habitat on Earth

• niche• Biotic factors• Abiotic factors

Adaptations

• Mouthparts:• Butterfly tongue is

long and sticky, an ant has a sharp mouth for cutting, a fly’s tongue is like a sponge

• Exoskeleton• Camouflage

Crustaceans

• Shrimp, lobsters, and crabs

• 2-3 body sections• 5 or more pairs of

legs• 2 pairs of antennae• Most have gills• metamorphosis

Arachnids

• Spiders, ticks, mites, and scorpions

• 2 body sections – head and abdomen

• 4 pairs of legs• No antennae• These are usually

predators – some have venom

Centipedes and Millipedes

• 2 body sections- head and abdomen

• Many pairs of legs• Centipedes – have

1 pair of legs per segment

• Millipedes- have 2 pairs of legs per segment

• Terrestrial habitat

Hexapods

• All insects• 3 body sections- head,

thorax, and abdomen• 1 pair antennae• 1-2 pairs of wings• Airholes in exoskeleton

called spiracles• Metamorphosis• Camouflage